DE102008020825B4 - Concept for the secure distribution of information - Google Patents

Abstract

A management message generator (100) for generating at least two message parts carrying information for decrypting content in terminals of different security classes, comprising:
encryption means (103) for encrypting a content key (106); and
a message generator (104) for generating a first message part (101) and a second message part (102),
wherein the encryption means (103) is adapted to encrypt the content key (106) with a first service key (107) to generate a first encrypted content key (109), and wherein the encryption means (103) is adapted to store the content key (103). 106) with a second service key (108) to generate a second encrypted content key (110), the first service key (107) being different from the second service key (108); and
wherein the message generator (104) is adapted to generate the first message part (101) such that the first message part (101) associates the first encrypted content key (109) and a first security class identifier (111) associated with the first service key (107) is, includes, ...

Description

embodiments of the present invention relate to a management message generator, a content key provider, a content and management message generator, a content delivery and further processing apparatus, a system for encrypted transmission a content key, a system for the secure distribution of information and associated procedures and a corresponding computer program.

These enable for example, a regulated access to protected multimedia content. They are used, for example, where digital content is distributed and consumed, e.g. B. over a digital audio and video broadcasting system (DAB, DVB system), a mobile communication system (GSM, UMTS, CDMA system) digital multimedia system (DMB system), an internet protocol communication system (IP system) or a digital navigation or driver assistance system.

digital Rights management systems or DRM systems refer to procedures to control the use and distribution of digital media can. Especially with digitally available film and sound recordings, but also with software, electronic documents, electronic books or electronic services use digital usage management. It allows Providers of such digital rights management systems for Use control of their data, new billing options, for example by means of licenses or rights of use rights data rather than the data itself.

author and recyclers often have an interest in the dissemination and use of their spiritual To control or restrict ownership even after disclosure. One digital rights management system should help by providing the Use of data only in that of the respective rights holders defined framework, d. H. the license.

meanwhile find digital rights management systems but also in many others Areas application, z. In companies to protect documents, and are also referred to herein as corporate rights management systems.

digital Rights management systems are a technical security measure, to give a right holder of information goods the possibility of the kind the use of his property by users based on a previously technically enforce the agreement. Additionally allow digital rights management systems the exploitation of digital content beyond a pure standard fee and allow for individual licensing or billing according to frequency, Duration or extent of use. Thus, on the one hand, the unlimited Use restrictable, on the other hand become business models on request, that were hardly realizable before.

Examples digital rights management systems are the OMA DRM 1.0 and 2.0 System of as "Open Mobile Alliance " Standard, the "ISMA Encryption and Authentication System of the as "Internet Streaming Media Alliance " and the "EUROCRYPT" system of the ETSI standard EN 50094. Additionally there is a big one Number of proprietary digital rights management systems, eg B. "Fair Play" of the provider Apple, "Windows Media DRM "of the Provider Microsoft.

In Future could digital rights management systems in many other areas as well, as in the automotive sector, d. H. for software protection or for online navigation or play a bigger role in embedded systems.

digital Rights management systems realize the idea of access control digital content using cryptographic methods. implemented This is done by adding any digital content through encryption clearly bound to a license. Without the to the digital content associated valid license Although the user can use the device or the disk and acquire digital content, but not access the content.

Of the Content Management Computer manages the digital content to be protected and encrypts these for use in a digital rights management system, whereby the contents become unreadable for the time being. The license management calculator Generates the required licenses along with the associated keys for the User Authentication and Content Decryption, which are from the corresponding Identifiers are calculated. Would like to the user on a protected Access content, and there is a bidirectional connection between digital rights management control and license management computer, requests the digital rights management control from the license management computer the license necessary for the reproduction. If authenticity and integrity of the playback program have been successfully verified, the content will be in the License key decrypted on made that way readable again and to the playback program passed.

Conditional access systems or access encryption systems, including CA systems called, z. As used in pay-TV systems for encryption and decryption of the program content, which are now used in digital radio / radio systems and vehicle assistant systems.

In order to a receiver is able to decode the contents, he needs a constantly changing Control word. To send this control word to the recipient and only certain recipients to address is the task of conditional access systems.

Of the Provider sends separate data packets parallel to the user data as administrative messages or "ECM messages". By means of these ECM messages a correspondingly authorized recipient can calculate the valid control word at that time and submit to the content decoder. This can decrypt the received content. At the receiver side an access authorization system, eg. B. bound by a customer Authorization card in the form of a "smart card" and a customer-anonymous access authorization module. The module filters doing the packets with administrative messages from the data stream and calculated by means of the given information in connection with the Authorization card the corresponding control word. The logic of Conditional access system is distributed on the one hand to the module and on the other hand on the authorization card. It is customary, custom Data on the authorization card and these are not readable to make it through third.

In addition to the information that is already on the authorization card of the customer The procedures send administrative messages about the administrative commands contain incoming data stream. These administrative messages, too referred to as EMM commands, are used for specific activation or Deactivate the loyalty cards. There is also the possibility the customer more or less rights regarding individual offer packages grant, without the customer needing to swap the authorization card.

Examples digital conditional access systems are the "Betacrypt" and the "Betacrypt 2" system for digital pay-TV, that for developed an application called "D-Box" and the video Guard "system for pay-TV, broadband television and mobile applications as well as the "Nagra Vision Aladin" system, that for both Satellite as well as cable television access authorization procedures offering.

There Receiver usually unable to confirm received messages and Also, not all are turned on, all messages, for example repeatedly to ensure high quality reception. In order to achieve a high security standard, the conditional access messages are so securely encrypted, that a decryption without valid access key either economically not feasible or technically almost impossible. Furthermore, different individual conditional access systems in the way of each other separated, that they can not influence each other.

The Content is encrypted before distribution. In additional Administrative messages become the usage rules, as well as required cryptographic key for decryption content distributed to users. The contents can be at your service be grouped. The users of a service are a group of People. These can be different terminals have. Typical terminals are z. A mobile phone, a personal digital assistance system, d. H. a PDA, a portable navigation assistance system, d. H. one PNA, a fixed or portable computer, d. H. a PC, a firmly installed receiver device in the car, d. H. an OEM device. The terminal side Implementation and validation is the responsibility of the respective device manufacturer.

The Differentiation between DRM and CA systems is increasingly losing in importance. Requirements and concepts of both systems merge. OMA DRM 2.0 was z. For example, it has been expanded to include a func-related concept ("GRANNY DRM V 2.0 Extensions for Broadcast Support ").

Next the application in the area of "Pay-TV" or pay-TV are digital radio systems, eg. B. DAB / DMB with predominantly portable terminals without return channel ( "Unidirectional Connection ") a possible one Operation area. Hereby can both encrypted as well as unencrypted Service content, eg. B. transferred from the field of traffic telematics become.

Previous proprietary digital rights management systems and conditional access systems (DRM and CA systems), where all system components are from one manufacturer come, and one for the user unknown function, also as "Black Box ", increasingly lose importance. Open digital rights management systems and Conditional Access Systems (DRM and CA systems), which are used on a variety of physical (Hardware) platforms run and developed by various companies and integrated, are increasingly used. The increasingly colorful market of terminals leaves straight Mistrust and skepticism arise on security-related issues.

digital Rights Management Systems and Conditional Access Systems (DRM and CA systems) are particularly vulnerable to attacks by unauthorized persons Persons exposed z. B. want to compromise service key. For maximum security of the overall system should all terminal devices with security modules after latest standard ("state of the art "or stand the technique) be, z. B. with a crypto chip card or a SIM card for user identification. The used terminals However, they do not have a uniform safety standard.

The in digital rights management systems and conditional access systems (DRM and CA systems) used terminals differ in terms of their safety standards, but also with regard to active life, price, Complexity, capacity ("Performance"), analysis options, User profile and manufacturer.

For example show a personal digital assistive device, d. H. a PDA, and a permanently installed receiver device in the car, d. H. an OEM device, partially contrary Parameter:

One personal digital assistant device has a low active lifetime and should be low in price have, what little complexity, a low efficiency ("Performance") and if necessary good analysis options entails. For example, the user is young and interested in technology, he could to be a potential attacker.

One firmly installed receiver device, d. H. an OEM device, in a vehicle has a long active life, a high Price, a high complexity, a high performance and poor analysis options, the user is usually not a potential attacker.

On the one hand can be a uniform safety standard due to the different Characteristics and Requirements, e.g. B. price and performance, can not be achieved. On the other hand, the different security concepts are difficult to judge and compare, especially since the manufacturers in this regard only reluctant to disclose security-related information.

in the Some rights administration systems or conditional access systems are described below.

Independent of The cryptographic algorithms used are based on digital Rights management systems or conditional access systems (DRM systems) and CA systems) always on a multi-level key hierarchy. The multimedia content is encrypted with a symmetric content key that cyclically changes. Examples of such systems are described in the standards "OMA DRM V2.0 Extensions for Broadcast Support "of the" Open Mobile Alliance "standardization or "ISMA Encryption and Authentication "the" Internet Streaming Media Alliance "standardization or "Access control system for the MAC / packet family EUROCRYPT ", EN 50094 ETSI standardization. In the legitimate terminal should the respective content key for decryption of the content. The content key itself becomes this in encrypted Form distributed with a management message. The content key is for example, encrypted with the service key. The authorized and registered terminals have the respective service key and can thus the current one. content key decrypt. A service key has a long life and can be used, for example, for all devices the permission for have a specific service and the same security class belong, be equal.

The naming of the keys and administrative messages described above may be different in digital rights management systems and conditional access systems (DRM and CA systems). 4a shows an example of the two standardizations OMA and EUROCRYPT. For example, the content key is referred to as "Traffic Encryption Key (TEK)" for encrypting and decrypting the service content in OMA standardization, while the same is referred to in the EUROCRYPT standardization as "Control Word (CW ) "(" Control word "). The management message transporting the content key to the terminal is referred to in the OMA standardization as a "Short Term Key Message" and in the EUROCRYPT standardization as an "Entitlement Control Message (ECM)" or Entitlement Control Message; The service key used to encrypt / decrypt the content key is referred to in the OMA standardization as the "Service / Program Encryption Key (SEK / PEK)" and in the EUROCRYPT standardization as a "service key" or service key; the management message, which transports the service key to the terminal, is called "Long Term Key Message" in OMA Standardization and Entitlement Management Message (EMM) or Entitlement Management Message in EUROCRYPT Standardization.

An example of the key hierarchy is in 4b for OMA standardization. Standardization distinguishes four different layers in the key hierarchy, which are the encrypted content 442 , the encrypted In hold key 432 , the encrypted service key 422 and the device registration data 403 transport: A first layer (layer 1) or registration layer 401 , a second layer (layer 2) or long-term key message layer 402 , a third layer (layer 3) or short-term key message layer 403 and a fourth layer (layer 4) or content encryption layer 404 , The content 440 is in the content encryption layer 404 via a content coder 441 to an encrypted content 442 encrypted and sent to a content decoder 443 transferred from the encrypted content 442 the content 444 reconstructed which is the original content 440 equivalent. The transmission of the encrypted content 442 may be directed or undirected, that is to say with the recipient's name or without indication of the recipient or receivable for all recipients.

To encrypt the content 440 in the content coder 441 is a content key 430 necessary with which the content 440 is encrypted. The content key 430 becomes in the short-term key message layer 403 generates or is available. He is needed to get the content 440 but at the same time via the content key encryptor 431 to an encrypted content key 432 encrypted and via the short-term key message layer 403 as an encrypted content key 432 transfer. At the receiving end, the encrypted content key becomes 432 in a content key decryptor 433 decrypted and the reconstructed content key 434 that's the content key 430 corresponds to, is used to decrypt the encrypted content 442 in the content decoder 443 used.

For encryption of the content key 430 in the content key encryptor 431 is another key as a service key 420 necessary. This service key 420 is in the long-term key message layer 402 it is created and available to the content key encrypter 431 forwarded. Similarly, the service key 420 even encrypted, with encryption in a service key encryptor 421 takes place. The service key encrypter 421 generates an encrypted service key 422 which is transmitted to the receiver. The recipient has a service key decryptor 423 with which he receives the encrypted service key 422 can decrypt and thus the reconstructed service key 424 present, the service key 420 corresponds to this with the encrypted content key 432 in the content key decoder 433 to decode. To encrypt the service key 420 in the service key encrypter 421 and for decrypting the encrypted service key 422 in the service key decryptor 423 is a minor key 402 necessary in the registration layer 401 is generated or this is available.

The sender has device registration data 403 and a public device key 404 in front. The device registration data 403 be with the public device key 404 in a registry encryptor 405 it is encrypted and it becomes the subordinate key 402 generated. The device registration data 403 are transmitted to the receiver, which consists of these in a device registry data encrypter 406 using the private device key 407 the subkey 402 generated. The subordinate key 402 is sent to the service key decryptor 423 passed with this key from the encrypted service key 422 the service key 424 reconstructed the service key 420 equivalent.

The frequency with which key and content data is transferred varies from layer to layer. The device registration data 403 For example, they are only transferred when the device is registered. The service key 420 in the long-term key message layer 402 is rarely transmitted and is valid for a longer period or even fixed. The content key 430 becomes in the short-term key message layer 403 Frequently transferred, it also changes at short intervals. The content 440 is in the content encryption layer 404 permanently or at least regularly transmitted.

The WO 2005/045554 A2 describes a system and method for using digital rights management to control conditional access to digital broadband content. A system and method for providing digital rights management in a broadcast environment is described. According to one embodiment, the digital rights management system broadcasts encrypted service keys over the mobile telephone network to a mobile terminal. The mobile terminal receives and uses the encrypted service key to decrypt encrypted content keys received from a DVB set-top box. The decrypted content keys are sent to the set-top box via a local connection where they are used to decrypt the encrypted broadcast content. In addition, the describes WO 2005/045554 A2 a mobile receiver power management technique that allows the receiver hardware to shut down during part of the rendering process.

The Object of the present invention is to provide a concept for to find secure distribution of information that takes into account that information to different devices with different security standards be distributed and that contributes to the compromise a device low-security does not compromise other devices with higher Safety standard.

The present problem is solved by a management message generator for generating at least Two message parts containing information for decrypting a Content in terminals wear different security classes, according to claim 1, or a method for producing the same, according to claim 23. Furthermore, the object is achieved by a content key provider for providing a content key for decryption a data content based on a management message that a plurality of encrypted ones content keys includes, where the encrypted content key assigned to different security classes, according to claim 13, or a method for providing the content key according to claim 24. The solution also includes a system for encrypted transmission a content key, the encryption mechanism from a content key according to the assigned security class, according to claim 32nd

Farther includes the solution a content and management message generator according to claim 25, a method for generating an encrypted content and a management message according to claim 27, a content providing and processing device according to claim 26, a method of providing a content key and to decrypt a content according to claim 28, a secure information distribution system according to claim 29 and a computer program according to claim 36.

One The core idea of the invention is that terminals have different security classes assign and an identical service depending on the security class different service keys assign. This gives devices different Security classes different service keys. So it is not anymore possible, at Compromise a terminal a low security class, d. H. Obtaining his service key, with this service key a machine higher Compromise security class because of the higher security class device another service key was assigned. Furthermore, it is possible to provide services for terminal classes Switch off centrally at the transmitting end, without this having an effect terminals other classes has.

The The concept described here classifies the terminals and leads to identical ones Services various service keys one. It is intended to prevent the compromise of a device, i. H. Analysis of the service key with low security standard compromising the whole digital rights management system or conditional access system (DRM and CA systems).

to solution The task defines different security classes of terminals, For example, integer security classes from 1 to n. The security classes can arising from disclosed security criteria or proprietary proprietary security classes be.

For example can be any device at least one security class. The assignment For example, in the production process or at a later date happen. Is a terminal For example, if exactly one security class is assigned, the same applies this class for everyone for the terminal unlocked services. Alternatively, a terminal may be dependent on the service Security classes are assigned. Each terminal can have its own Security class or its security classes.

For one identical service can assign different service keys depending on the security class and in the respective terminals get saved.

The used content key and cryptographic methods can be used for devices of all security classes be equal.

Instead of just generate a recent management message that matches the the service key encrypted content key transported to the terminal, can several administrative messages are generated and transmitted in parallel. For example, they each contain an identification that the Safety class represents, and the one encrypted with the corresponding service key Content key. For different Security classes may be different from the encoding of administrative messages be.

For example can in a single management message also multiple identifications, which represent the security classes and multiple times the identical content key is transmitted. This one can each encrypted with the service key assigned to the respective identification.

The terminal knows, for example, its own security class and its assigned Service key. The assignment of the service keys can for example take place via the same channel as the content distribution by means of a management message. Alternatively, for example, a transmission by an external interactive channel or a pre-initialization in device manufacturing is possible.

With Knowledge of the security class and the service key can the terminal the currently valid content key decrypt.

Of the Service content needs for all terminal types transmitted encrypted once only to become.

preferred embodiments The present invention will be described below with reference to FIG the enclosed drawings closer explained. Show it:

1 a block diagram of a management message generator according to an embodiment;

2 a block diagram of a content key provider according to an embodiment;

3a an example of a system consisting of two management message generators and four content key providers;

3b another example of a system consisting of two management message generators and four content key providers;

4a an example for naming the keys and corresponding key messages in the standardization for OMA and EUROCRYPT;

4b an example of executing the key hierarchy in OMA standardization;

5 an example of the key hierarchy from OMA standardization with integration of the security class concept;

6 an example of the security classes and assignment to the terminals;

7 an embodiment of the management message carrying the content key with two message parts or with a message part; and

8th an embodiment of a digital rights management or conditional access system with integration of the security class concept.

1 shows a block diagram of a management message generator 100 for generating at least two message parts 101 and 102 which carry information for decrypting a content in terminals of different security classes. The management message generator 100 includes an encryption device 103 and a message generator 104 , The management message generator 100 generates administrative messages 105 that the first message part 101 and the second message part 102 include. The administrative messages 105 represent, for example, the short-term key messages 432 out 4b used in OMA standardization to transmit the encrypted content key 432 can be used. The management message generator 100 can the in 4b specified content key encryptor 431 replace that from a content key 430 an encrypted content key 432 and the management message generator 100 from a content key 106 administrative messages in this embodiment 105 can generate the first message part 101 and a second message part 102 include.

This is the content key 106 an encryption device 103 supplied the content key 106 with a first service key 107 to a first encrypted content key 109 encrypted and the content key 106 with a second service key 108 to a second encrypted content key 110 encrypted. The service keys 107 . 108 can be analogous to 4b from the long-term key message layer 402 originate and are, for example, at the entrance of the management message generator 100 at. It is also possible to use the first and second service keys 107 . 108 directly in the management message generator 100 to create.

A difference to the concept according to 4b is that in the management message generator 100 according to 1 the content key 106 not with a single service key 420 but with a first service key 107 and a second service key 108 is encrypted. Both service keys are assigned to different security classes. Such is the first service key 107 a first security class identifier 111 zugeord net and the second service key 108 a second security class identifier 112 assigned. While at the management message generator 100 according to 1 the encryption device 103 the content key 106 only with two service keys 107 . 108 Encrypted, the encryption device 103 in an alternative embodiment, the content key 106 encrypt with all service keys associated with security classes. In other words, one uses, for example, nine different security classes, as in 6 specified, so can the content key 106 be encrypted with nine different service keys. For n different security classes, the content key can 106 be encrypted with n different service keys. In the embodiment according to 1 is the first security class identifier 111 associated with a first security class and the second security class identifier 112 assigned to a second security class, wherein the first security class differs from the second security class. For example, for nine or n security classes, there are 9 or n different security class identifiers and, accordingly, so many service keys. The security class identifiers 111 and 112 become the management message generator 100 supplied externally, for example, the security class identifiers 111 . 112 in the registration layer 401 corresponding 4b be generated and from there the encryption device 103 be supplied. However, it is also possible to use the security class identifiers 111 . 112 directly in the management message generator 100 to generate or save.

The message generator 104 generated with the first encrypted content key 109 , the second encrypted content key 110 , the first security class identifier 111 and the second security class identifier 112 a first message part 101 and a second message part 102 which the security class or security class identifier 111 respectively. 112 and the encrypted content key 109 respectively. 110 exhibit. Inside the message generator 104 generates, for example, a first message subgenerator 113 the first message part 101 from the first encrypted content key 109 and the first security class identifier 111 , A second message subgenerator 114 generates the second message part 102 from the second encrypted content key 110 and the second security class identifier 112 , For other security classes, the message generator 104 be executed with other message sub-generators that generate more message parts according to the additional security classes. The administrative messages 105 include the respective message parts 101 . 102 or more in other security classes. An example of such a management message is in 7 which will be explained later.

A Of course, differentiation of different message generators is not required, but serves here only for illustration. The production the message parts can with a single device or through a single computer program can be realized.

2 shows a block diagram of a content key provider, 200 according to an embodiment of the present invention. The content key provider, 200 For example, in the key hierarchy 4b of the OMA standard the content key decryptor 433 that is the short-key message 432 carrying the encrypted content key, the content key 434 reconstructed, correspond. The content key provider 200 decrypts one of the in the management message, 201 contained encrypted content key, 204 . 205 . 206 and provides a decrypted content key, 202 ready. The management message, 201 This usually contains not only an encrypted ten content key, as is the case in the OMA standard, but it contains a plurality of different encrypted content keys, which are assigned, for example, the security classes. For example, the management message includes 201 9 different encrypted content keys for 9 security classes, 204 . 205 . 206 , From the management message 201 will be in the facility 203 for providing an encrypted content key, an encrypted content key 207 generated. The management message 201 in this embodiment comprises a plurality of encrypted content keys, here represented by a first encrypted content key 204 , a second encrypted content key 205 and a last encrypted content key 206 , The device for providing an encrypted content key 203 determined from the management message 201 the part that has the corresponding encrypted content key, that is an attached security class information 208 or optionally a service information 209 equivalent.

In this embodiment, the security class information 208 to the first security class, which is why the management message 201 for example, the message part with the first encrypted content key 204 (which is assigned to the first security class) is selected and as an encrypted content key 207 provided.

The provided encrypted content key 207 is in the facility for decrypting the provided encrypted content key 210 with an associated service key 211 it decrypts and it becomes the decrypted content key 202 provided.

The security class information 208 with the administrative message 201 is searched for the corresponding encrypted content key, for example, results from a service type 213 wherein the means for providing security class information 212 for a first service type 214 a first security class information 216 provides and for a second type of service 215 a second security class information 217 provides. The provided security class information 208 the first security class information 216 or the second security class information 217 is used in the means for providing an encrypted content key 203 the encrypted content key 207 from the management message 201 provide.

The content key provider 200 is implemented, for example, on a first terminal. This terminal is assigned a security class, for example according to the exemplary embodiment in FIG 6 , If this first terminal uses only a single service, it needs only a single security class, but in general it is possible to perform different services on the first terminal. Each service can be assigned a different security class. The service type 213 indicates which service is involved and allows an association of a security class assigned to the corresponding service type. In this embodiment, the service type becomes 213 in the facility for providing security class information 212 a security class information 208 certainly. The device for providing security class information 212 can also be outside the content key provider 200 be implemented. The service type 213 or the security class information 208 can either be in the content key provider 200 present, or for example in the registration layer 401 according to 4b determined and the content key provider 200 or, for example, in the long-term key message layer 402 according to 4b be transmitted to the recipient, or in the form of device registration data 403 in the registration layer 401 be transferred to the recipient.

The service type 213 For example, it may have all possible service types, but it is also possible for the content key provider 200 only those types of service are supplied that correspond to services that are also assigned to the respective terminal. The service type 213 is a service key 211 assigned to decrypt the encrypted content key 207 in the device for decrypting the provided encrypted content key 210 needed to get the content key 202 provide.

The service key 211 for example, to the content key provider 200 from the outside and for example via the long-term key message layer 402 according to 4b transferred to the recipient or directly in the content key provider 200 present or optional (the dashed arrow line from 2 accordingly) from the service type 213 be determined. For example, this may be optional in the service key provider 218 be effected for the first type of service 214 a first service key 219 and for the second type of service 215 a second service key 220 provides. Depending on the applicable service type 213 becomes the service key provided 211 then the institution 210 to decrypt the provided encrypted content key 207 fed.

The content key provider 200 For example, in the key hierarchy in 4b specified content key decoder 433 replace, with the difference being that the content key provider 200 from a management message 201 the encrypted content key 207 which is assigned to a security class specified by the respective service type. That is, the content key provider 200 determined with the respective safety class 212 service key corresponding to the service 211 the associated content key 202 from the one in the management message 201 contained encrypted content key 207 , the service type 213 the appropriate security class 212 assigned. For each service type 213 the result is preferably a different content key 202 according to the chosen service. Preferably, each terminal type is assigned a different security class and, in addition, each type of service 213 also a different security class 212 be assigned so that different security classes 212 for each one terminal type and one service type each 213 can be distinguished. This relationship will be further discussed in 3a and 3b clarified.

3a shows a system that has two management message generators 300 . 320 and four content key providers 334 . 337 . 338 . 339 includes. This creates a management message generator 300 the administrative messages 302 . 322 for a first service. The first service is a first content key 301 from which in the management message generator for the first service 300 a first management message 302 is produced. The first management message 302 has a first encrypted content key 303 and a second encrypted content key 304 on. At the management message generator for the first service 300 lie a first service key 305 with a first security class identifier 306 so like a second service key 307 with a second security class identifier 308 so that the management message generator for the first service 300 the management message 302 with all encrypted content keys 303 . 304 which identifies the security class identifiers 306 . 308 for which the first service is unlocked. The service key 309 is in accordance with the name in 3a generally specified or grouped or linked with two indexes, in the form that the first index 310 denotes the service and the second index 311 the security class 212 denotes, in this embodiment, the first service two security classes 212 are assigned and thus two service keys 305 and 307 at the management message generator for the first service 300 issue.

As mentioned earlier, the content key 301 for the first service also with several service keys 305 . 307 the corresponding security classes 306 . 308 be encrypted. Then assigns the first management message 302 multiple encrypted content keys 303 . 304 depending on how many security classes 212 the first service with the first content key 301 is unlocked. That is, the first management message 302 then includes as many elements as security classes 212 are defined for the first service. The elements designate the encrypted content keys 312 which as the first index 313 the service and as a second index 314 the security class 212 exhibit. The security class identifier 315 can also be described as an element with two indices, where the first index 316 the service and the second index 317 the security class 212 designated.

In this embodiment, the second service becomes the management message generator 320 edited for the second service and provides from a second content key 321 a second management message 322 ready. At the management message generator for the second service 320 lie a third service key 325 with associated third security class identifier 326 and a fourth service key 327 with associated fourth security class identifier 328 at. The service keys 325 . 327 and the security class identifiers 326 . 328 are denoted by two indexes, where the index is for the service 310 a 2 has according to the second service and wherein the security class 311 for the third service key 325 a 1 and for the fourth service key 327 has a 2. However, it is also possible to define different security classes for the second service than for the first service. Another embodiment in this regard is in the following 3b specified. In 3a become from the first content key 301 and the second content key 321 a first management message 302 and a second management message 322 generated, which are supplied to the receivers.

The system consists of four content key providers on the receiver side 334 . 337 . 338 . 339 where two terminals 330 . 342 are shown, the two content key providers 334 . 337 . 338 . 339 exhibit.

A first terminal 330 In this embodiment, two services are assigned. The first service needs the first content key 301 in the first terminal 330 can be reconstructed. The second service needs the second content key 321 in the first terminal 330 can also be reconstructed. The content key 301 for the first service may be in the first terminal 330 by means of the content key provider 334 for the first service on the first terminal from the received management message 333 to be provided. The management message 333 includes the first encrypted content key 303 , the second encrypted content key 304 , the third encrypted content key 335 and the fourth encrypted content key 336 , That is, the management message 333 In this embodiment, all encrypted content keys included by the first message management message generator 300 and the management message generator for the second service 320 generated according to the unlocked security classes for the two services. According to the security class identifier associated with the first service type 306 can the management message 333 according to the associated encrypted content key 303 be searched with the associated service key 305 can be decrypted. The security class identifier 306 and the service key 305 are in this example the first type of service on the first terminal 330 assigned. The content key provider for the first service on the first terminal 334 represents from the management message 333 the first content key 301 ready.

For the second service on the first terminal 330 can be a second content key 321 be reconstructed. The management message 333 has a similar structure, ie it comprises a first encrypted content key 303 , a second encrypted content key 304 , a third encrypted content key 335 and a fourth encrypted content key 336 , The content key provider 337 for the second service on the first terminal searches the management message 333 by means of the security class identifier associated with the second service type 326 according to the associated encrypted content key 335 from. The second type of service on the first terminal 330 associated encrypted content keys 335 is with the associated service key 325 of the second service on the first terminal 330 decrypted and the content key provider 337 for the second service on the first terminal provides the second content key 321 ready.

On the second terminal 342 is, for example, a content key provider 338 implemented for the first service on the second terminal and a content key provider 339 for the second service on the second terminal. The management message 333 can from the content key provider 338 for the first service on the second terminal and by means of the associated security class identifier 308 , the first type of service for the second terminal 342 is assigned after the encrypted content key 304 be searched. The found encrypted content key 304 can with the associated service key 307 are decrypted for the first service on the second terminal, so that the content key provider 338 for the first service on the second terminal, a first content key 301 which is necessary to decrypt the first service.

In a content key provider 339 for a second service on the second terminal, the management message 333 received by the content key provider and by means of associated security class identifier 328 , the second type of service on the second terminal 342 assigned to the appropriate encrypted content key 336 be searched. The encrypted content key 336 can by means of associated service key 327 decrypted assigned to the second service on the second terminal. The content key provider 339 for the second service on the second terminal provides the second content key 321 ready to receive the contents of the second service on the second terminal 342 to decode.

The system in this embodiment includes two management message generators 300 . 320 that are administrative messages for two services 302 . 322 generate the respective encrypted content key 303 . 304 . 335 . 336 include. Preferably, different encrypted content keys 303 . 304 . 335 . 336 depending on the service 313 and after security class 314 used. On the producer side, for example, administrative messages 302 . 322 generates the encrypted content key 303 . 304 . 335 . 336 for all services offered and for all security classes that can be assigned to existing terminals. On the receiver side can from the management message 333 the individual encrypted content key associated with the security class identifier of the corresponding terminal is selected.

3b shows an embodiment of a block diagram having the same structure as the block diagram of the embodiment 3a , The difference is that the management message generator for the first service 300 the generated administrative message 349 different encrypted content keys 304 . 345 assigns as opposed to the example 3a different service keys 307 . 343 and security class identifiers 308 . 344 at the management message generator for the first service 300 issue. The same applies to the management message generator for the second service 320 ,

The management message generator 300 for example, the first service may be from the first content key 301 an administrative message 349 generate an encrypted content key 304 includes that of the second security class 314 for the first service 313 and an encrypted content key 345 includes, the sixth security class 314 for the first service 313 is assigned. The management message 349 can depend on the service key 307 , the second security class 311 for the first service 310 and the security class identifier 308 , the second security class 317 for the first service 316 assigned as well as the service key 343 , the sixth security class 311 for the first service 310 and the security class identifier 344 , the sixth security class 317 for the first service 316 is assigned to be generated.

The management message generator for the second service 320 for example, from the second content key 321 an administrative message 350 produce. The management message 350 can be an encrypted content key 346 , the fifth security class 314 for the second service 313 and an encrypted content key 347 , the ninth safety class 314 for the second service 313 corresponds to include. The management message 350 can from the second content key 321 using the service key 375 , the fifth security class 311 for the second service 310 and the security class identifier 376 , the fifth security class 317 for the second service 316 is assigned, and the service key 377 the ninth safety class 311 for the second service 310 is assigned, as well as the Si cherheitsklassenidentifizierer 378 , the ninth safety class 317 for the second service 316 is assigned to be generated.

At the receiver side, the system comprises a first terminal 360 and a second terminal 361 for example, different from the first terminal 330 and the second terminal 342 out 3a are executed. The first terminal 360 in this embodiment includes a content key provider for the first service on the first terminal 361 , and a content key provider for the second service on the first terminal 362 , The second terminal 361 comprises a content key provider for the first service on the second terminal 363 and a content key provider for the second service on the second terminal 364 , All four content key providers receive the same management message 351 which is different from, for example, the management message 333 from the embodiment according to 3a , because the two terminals off 3b In this embodiment, other security classes are assigned than the terminals 3a , Although the management message 351 in this example, includes other encrypted content keys than the management message 333 out 3a Thus, the content key provider for the first service reconstructs on the first terminal 361 however, the same first content key 301 for the first service, which is also on the first terminal 330 in 3a is reconstructed. In this case, the management message 351 using the security class identifier 308 for example, the first service 316 on a device of the second security class 317 is assigned after the encrypted content key 304 which are searched with the service key 307 For example, the first service can be decrypted 310 on devices of the second security class 311 equivalent. As a result of decryption, the first content key 301 to be provided.

The content key provider for the second service on the first terminal 362 can the management message 351 with the security class identifier 376 who is the second service 316 on devices of the fifth security class 317 is assigned after the encrypted content key 346 search and the encrypted content key 346 with the service key 375 who is the second service 310 on devices of the. fifth safety class 311 is assigned to decrypt the second content key 321 provide.

On the second terminal 361 For example, the content key provider for the first service may be on the second terminal 363 the management message 351 by means of the security class identifier 344 for example, the first service 316 on devices of the sixth security class 317 is assigned after the encrypted content key 345 search and the encrypted content key 345 with the assigned service key 343 , the first service 310 on devices of the sixth security class 311 is assigned, decrypt to the first content key 301 provide.

The content key provider for the second service on the second terminal 364 can the management message 351 by means of the security class identifier 378 for example, the second service 316 for devices of the ninth safety class 317 assigned to the encrypted content key 347 search and the encrypted content key 347 with the service key 377 who is the second service 310 for devices of the ninth safety class 311 is assigned to decrypt the second content key 321 provide.

4a shows an association of the various terms content key, service key and management messages that transport the content key to the terminal or transport the service key to the terminal for the two standards OMA and EUROCRYPT. Details have already been explained in the upper part of this application.

4b shows a block diagram of the key hierarchy of the OMA standard, which can also be applied to other standards. The key hierarchy is in four layers 401 . 402 . 403 . 404 built the encrypted content 442 , the encrypted content key 432 , the encrypted service key 422 and the device registration data 403 transport. Further details have already been explained in the upper part of this application.

5 shows an embodiment of a key hierarchy, in which the security class concept according to the invention can be integrated, for example. The key hierarchy consists of four layers: a fourth layer (layer 4) 404 to transport the encrypted content 442 , a third layer (layer 3) 403 for transporting short-term key messages 432 , a second layer (layer 2) 402 for the transport of long-term key messages 422 and a first layer (layer 1) 401 to transport the registration data 403 ,

In layer 4 404 the encrypted content transport layer is, for example, according to the OMA standard, as in 4b described the content 440 a content coder 441 Trains leads the content 440 using the content key 430 encrypted and the encrypted content 442 generated. This is transported to the recipient and there with the help of a content decoder 443 using the content key 434 decrypted, so that on the receiver side the content 444 is present.

In the content 440 . 444 it may, for example, be a stream of audio or video data or multimedia data conveying voice information or image information or messages. In the content 440 . 444 they can also be objects such as control information of a navigation or driver assistance system or a computing system or information for which a user is interested. Furthermore, the content 440 . 444 For example, a file that is provided to a user by a service provider.

The content key 430 to encrypt the content 440 becomes in the third layer 403 Generating short-term message layer or is available there. The function of the content key encryptor 431 out 4b can in 5 the management message generator 100 take. This can be from the content key 430 with the help of a service key 420 or multiple service keys and one or more security class identifiers 111 . 112 an administrative message 432 generate one or more encrypted content keys, depending on how many security class identifiers 111 . 112 with assigned service keys 420 exist. The administrative messages 432 For example, they include multiple message parts and can handle the management messages 105 correspond. The administrative messages 432 arrive at the receiver side on the content key provider 200 and there they are using the service key assigned to the receiver 424 and the service type assigned to the recipient 213 decrypted, and it becomes the content key 434 provided.

The (optional) second layer 402 includes the long-term key messages 422 and puts the service key 420 or for several security classes, the service keys 420 ready. The service keys 420 become for the management message generator 100 needed to get the content key 430 to encrypt and the administrative messages 432 to create. The service keys 420 can through a service key encryptor 421 with the help of a subkey 402 be encrypted and as long-term key messages 422 be transmitted to the recipient. The receiver can notify the long-term key messages 422 in the service key decryptor 423 using the subkey 402 decrypt and the service keys 424 provide for the content key provider 200 needed to manage the administrative messages 432 to search for the encrypted content key and the content key 434 provide.

In the (optional) first layer 401 or the registration layer can on the sender side registration data 403 containing one or more service types 213 and one or more security class identifiers 111 . 112 be provided. The security class identifiers 111 . 112 can the management message generator 100 be fed so that this from the content key 430 provide an associated encrypted content key for each security class. The registration data 403 can in the first layer 401 for example, with a public device key 404 in the registry data encrypter 405 be encrypted and transmitted to the recipient. In the receiver may be in the first layer 401 from the registration data 403 in encrypted form, in the registry data decryptor 406 For example, using the present in the receiver private device key 407 the subordinate key 402 be decrypted. From the registration data 403 For example, the types of service 213 read out and the content key provider 200 be made available so that this from the encrypted content keys in the administrative messages 432 can be included, one of its service type 213 corresponding content key 434 can provide. It can, for example, for different types of service 213 from the administrative messages comprising the encrypted content keys 432 different content keys 434 be reconstructed.

The assignment of the security class identifiers 112 . 111 as well as the service types 213 is the task of the registration layer in this embodiment 401 , Alternative assignments are also possible, ie the security class identifiers 111 . 112 may also be in the management message generator 100 be generated or the service types 213 can be in the content key provider 200 be generated. It is also possible to use the security class identifiers 111 . 112 or the service types 213 over the second layer 402 by means of long-term key messages 420 transferred to. Furthermore, it also makes sense, for example, to use an external channel to transmit the security-relevant information.

In this embodiment, the key hierarchy of the OMA standard has been varied in such a way that the content key encryptor 431 by the management message generator 100 replaced and the content key decrypter 433 through the content key provider 200 was replaced. The ger of the management message generator 100 generated administrative messages 432 can compare with the short-term key messages 432 the OMA standard next to the encrypted content key contain a countable number of other encrypted content key, for example, for each content key 430 as many encrypted content keys as different security class identifiers can be generated 111 . 112 exist or should be used. Thus, if only an encrypted content key is transmitted in the OMA standard, so many encrypted content keys can be transmitted in the method according to the invention as security classes are defined or should be used.

The security classes 111 . 112 and the service types 213 can in the registration layer 401 can be provided and via the registration data encryptor 405 within the registration data 403 be transferred to the recipient. While in the OMA standard according to the embodiment of 4b a service key via the service key encrypter 421 is transferred to the receiver, in the embodiment of the invention even for a single service a plurality of service keys 420 which corresponds to the majority of the security classes assigned to the terminals.

The management message generator 100 In one embodiment, it may be configured such that the first message part of the management messages 432 additionally a service type 213 and that the second message part is generated so that the second message part additionally the service type 213 includes. First and second news section of the administrative news 432 For example, in one embodiment, the management message may be encoded as a function of the security class identifier 111 . 112 having. For example, a coding can be used which depends on the security class identifier 111 . 112 the administrative message 432 assigns a different number of code units, so that message parts of the management messages 432 which are assigned to a higher or higher security class, are mapped by a higher-order code or to a larger number of code units.

In the same way, the management message generator 100 for example, message parts 101 . 102 the administrative news 105 that a higher security class 111 . 112 match, assign greater redundancy so that the encrypted content key 432 a higher security class 111 . 112 are protected to a greater extent against interference during transmission.

In one embodiment, the management message generator is 100 for example, designed to be the content key 430 with a symmetric cryptographic key using an AES block encryption algorithm or a DES block encryption algorithm. For example, a symmetric cryptographic key refers to an encryption method in which both the sender and the recipient are assigned the same key. Or in which their keys are different but can be derived from each other by means of a known relationship. Block encryption algorithms, for example, use a block of plain text and a key, and generate a block of encrypted text of the same length. Since messages are usually longer than a single block, a method is needed to tie together successive blocks. Several methods have been developed in this regard, some with higher safety in one aspect, others with higher safety in another aspect.

To secure the transfer of keys in the administrative messages 422 . 432 ie in EMM 422 and ECM 432 Messages, the keys themselves are encrypted. In one embodiment, the service keys may be after the AES 256 Procedures and the content keys according to the AES 128 Procedures are encrypted. In either case, the ECB mode, also referred to as the "Electronic Code Book" mode, may be employed as described in the aforementioned NIST Standard.

Message authentication will be the management messages 432 and the long-term key messages 422 with an electronic signature or authentication according to a MAC method, or "message authentication code" or message authentication code method called authenticated. The sender attaches an authentication code to each message, and the recipient verifies that the authentication code matches the message, thereby verifying their authentication. For example, the administrative messages 432 or the long-term key messages 422 authenticated according to an OMAC procedure, ie a one key message authentication code method. The OMAC procedure is described in the NIST standardization. For example, a message authentication code can be used in which a plurality of parameters are transmitted by Huffman coding become. The administrative messages 432 may also include a timestamp to facilitate reconstruction at the receiver.

An example of the assignment of security classes to terminals is in 6 specified. As in 6 By way of example, at least one security class can be assigned to each device. Here are a total of nine security classes shown, which can be extended to any integer number of security classes. Alternatively, fewer security classes can be used. The table in the left column lists the security class and the right column lists criteria that devices should meet to be assigned to the appropriate security class. For example, security class 1 only has devices that use a crypto-smartcard or an intelligent encryption card or SC-card for secure storage of all keys and security-relevant parameters. The crypto-smartcard interprets and processes all administrative messages, no key leaves the crypto-smartcard and also the content is decrypted only in the crypto-smartcard.

Of the For example, security class 2 is associated with devices that have a crypto-smartcard for secure storage of all keys and security relevant Use parameters, with the crypto-smartcard all administrative messages interpret and process, and only the short-lived content key the Crypto SmartCard leaves. The decryption the content happens in the terminal.

Of the Security class 3 is, for example, a crypto-smartcard or a other external security device, z. B. a security card for digital media, also as an SD card assigned, if both devices for secure storage the key and the safety-related parameters are used and the interpretation and processing all administrative messages and decryption content in the terminal happen.

In For example, security class 4 may be an OEM device Device one Be classified third party, which is permanently installed in the vehicle and therefore very difficult to access can be. The use of in-vehicle safety components will with this device causes.

In For example, security class 5 may be classified as a portable terminal be that has an integrated built-in processor chip, the exclusively all digital rights management and conditional access system relevant Tasks takes over. The chip or processor can withstand special hardware-based attacks be protected.

In For example, security class 6 may be classified as a portable terminal be that has an integrated built-in processor chip that exclusively all digital rights management and conditional access system relevant Takes over tasks, where the chip may be a standard chip, the is not protected against special hardware based attacks.

In For example, security class 7 may be classified as a portable terminal be that one called "WinCE" Operating system of the manufacturer Microsoft has and no additional contains hardware-based security modules.

In For example, the security class 8 may be classified as a PC-based terminal be that one called "Obfuscation" Method uses.

In For example, security class 9 may be a proprietary device of a Manufacturer "XY" classified which does not disclose implementation details.

It can For example, follow other security classes associated with devices can be. Of course another assignment of safety classes to device types is possible.

7 shows an embodiment, which parts of the management messages according to the invention 105 out 1 consisting of a first message part 101 and a second message part 102 , may include. For example, the administrative messages 105 the first message part 101 according to a first message field 700 include and the second message part 102 according to a second message field 701 include. This is through the management message 700 that the content key 106 transported addressed for type 1 terminals, and the parallel management message 701 that have the identical content key 106 transported, but which is addressed for type 5 terminals, in the upper part of the 7 illustrated.

In another embodiment, it is also possible that both message parts are described by a single management message. In this other embodiment, in the lower part of the 7 is an administrative message 702 shown the content key 106 transported, which is addressed for type 1 and 5 terminals.

Is the management message 105 from two message parts 101 . 102 so does the ers te message part, in this example with 700 denotes a security class identifier 711 and a content key encrypted with the first service key 710 , The second message part, in this example with 701 includes a security class identifier 713 and a content key encrypted with the fifth (generally, another) service key 712 , The first message part 700 is for example generated for terminals of the first security class, while the second message part 701 is generated for terminal with the fifth security class (in general: another security class). The first message part 700 can still use a service identifier 714 and the second message part 701 can use the same service identifier 714 include, for example, both message parts 700 and 701 transport encrypted content keys of the same service. Furthermore, the first message part 700 and the second message part 701 a field for further parameters 715 respectively. 716 include. The coding of the first message part 700 or the second message part 701 can depend on the security class, ie higher-order code or greater redundancy can be used, for example, for higher-grade security classes.

In another possible embodiment, the management message 105 contain only a part of a security class identifier 711 for the first security class, a content key encrypted with the first security class service key 710 and a security class identifier of the fifth security class 713 (general: another security class) and a content key encrypted with the service key of the fifth security class (generally: another security class) 712 includes. Furthermore, the management message, in this example with 702 also identifies the service identifier 714 include. Furthermore, it is possible to use the management message 702 build in the way that the two message parts 700 and 701 be added in a row and so the management message 702 produce. In this case, the service identifier would be 714 twice in the management message 702 be included. The management message 702 may also be associated with parameters associated with the first security class 715 and parameters associated with the fifth security class 716 include. The parts of the management message associated with the first security class 702 may be coded depending on the first security class, while the parts associated with the fifth security class may be administrative message 702 can be coded depending on the fifth security class.

According to this embodiment 7 the encryption of the content key and the message structure for two security classes is shown by way of example, namely with the first security class and the fifth security class. In another embodiment, in addition to or instead of the two message parts 700 and 701 also more message parts are generated. For example, for an integer number of security classes 711 . 713 the same number of message parts are generated containing an encrypted content key 710 . 712 which is encrypted with one of the service keys, respectively. The management message 702 can handle all encrypted content keys 710 . 712 using service keys of existing security classes 711 . 713 Encrypted include, but it can also be summarized individual message parts and in one, two or more administrative messages 702 be transmitted.

The first message part 700 or the second message part 701 For example, it can be made up of a necessary part and an optional part. The necessary part may then, for example, the content key encrypted with the service key 710 respectively. 712 while the optional part includes the security class identifier of the first security class 711 or the fifth security class 713 may include. For example, existing terminals that have not been assigned or can not be assigned a security class can then receive only the necessary part of the management messages containing the content key encrypted with the service key 710 . 712 includes. The security class identifier 711 . 713 then, for example, in the optional part of the management message 105 be transmitted, so that terminals have been assigned a security class, the management message 700 . 701 . 702 with the security class identifier 711 respectively. 713 and the content key encrypted with the service key of the associated security class 710 respectively. 712 can receive. This makes it possible, even devices that have not been assigned a security class or the extended by security class message parts 700 . 701 . 702 can not understand, to address.

Alternatively, a zeroth device class can be defined, for example, denoted by "0", which automatically includes all terminals. This is referred to below as the base class. Service providers, for example, who do not want to support the concept presented and the associated additional administrative messages, for example, service their services via the base class. For example, it would be possible to assign the zeroth security class to the base class so that the first message part 700 in the management message 105 to egg is transmitted to the base class receiver of the message part encoded with the zeroth security class 700 can read. This would be possible, for example, if the first message part 700 for the base class without security-class-dependent coding.

8th shows a block diagram of an embodiment of a system 800 for the secure distribution of information between a service provider 801 and a service user 802 , The service provider 801 For example, provides a service that the service user 802 can use. The system 800 includes a content and management message generator 803 , a transmission device 804 and a content providing and processing device 805 , Even though in this figure only the fourth layer 404 as well as the third layer 403 according to the key hierarchy 4b or 5 are shown, the system can 800 also (optionally) the lower layers, ie the second layer 402 and the first layer 401 include.

The content and management message generator 803 can from the content 440 by means of the content encryptor 441 an encrypted content 442 produce. The content encrypter 441 For example, it encrypts the content 440 with the content key 430 , The content key 430 can in the management message generator 100 with a service key 420 the associated security class identifier 111 . 112 encrypted and encrypted content keys and associated security class identifiers 111 . 112 an administrative message 432 generate, which together with the encrypted content 442 via the transmission device 804 can be transmitted to the receiver. In the content providing and processing device 805 the recipient may receive the encrypted content 442 the content provider 443 feeds and the management message 432 the content key provider 200 be fed.

The content key provider 200 can from the management message 432 with the help of the service terminal assigned to the corresponding terminal 424 and the service type 213 on the terminal assigned security class the content key 434 determine this and the content provider 443 feed the encrypted content 442 to decode and the content 440 to reconstruct. The content 440 may be a content providing and processing device 805 a further processing device 808 be supplied. A further processing of the content 440 For example, an evaluation of the data, a transfer to another device or a reproduction of the content 440 include. The further processing device 808 For example, it may comprise an audio code decoder or be an audio player or may comprise a video code decoder or be a video player. The further processing device 808 For example, it may also be a navigation device, or a mobile phone or a personal digital assistant device or a digital multimedia receiving cable receiver or a digital multimedia receiving satellite receiver or a communication system for internet protocols or a driver assistance system or a personal computer, or part thereof. Generally, the content 440 So be provided to an electronic content receiver.

The system 800 for the secure distribution of information between a service provider 801 and a service user 802 can be a subsystem 806 which is designed for the encrypted transmission of a content key. This subsystem 806 for encrypted transmission of a content key in this embodiment comprises a management message generator 100 , a management message transmission device 807 and a content key provider 200 , The system 806 for encrypted transmission of a content key, a content key 430 be supplied as well as one or more service keys 420 and associated security class identifiers 111 . 112 , From these input variables, the management message generator 100 an administrative message 432 generated by the administrative message transmission device 807 can be transmitted to the receiver. The recipient can use the content key provider 200 include the administrative message 432 by means of a service key present on the terminal 424 or multiple service keys 424 and one the service keys 424 assigned service type 213 or multiple service types 213 searches for the corresponding encrypted content key and from it the content key 434 provides.

The system 806 For encrypted transmission of a content key, a subsystem of the system 800 for the secure distribution of information between a service provider 801 and a service user 802 be. The system 806 may be the transmission of an encrypted content key from a management message generator implemented in the sender 100 to a content key provider implemented in the receiver 200 include. The system 800 can the content 440 a service provider service 801 along with the associated content key 430 in a secure manner to a service user 802 Distributed here, being secured here means that a class of terminals have a security class and that for each class of terminal with own security class a separate encrypted content key in the management message 432 can be transferred. Additionally, each service type can 213 be assigned a separate security class on a terminal. Depending on the service, different security classes can be assigned to a terminal or, if a terminal is assigned exactly one security class, this class can apply to all services enabled for the terminal. The system 800 may be designed, for example, according to one of the standards OMA, ISMA or EUROCRYPT; The same applies to the second system 806 , The transmission device 804 or the management message transmission device 807 may be a digital or analog broadcasting system (eg, a digital audio broadcasting system or a digital video broadcasting system) or a mobile radio communication system or a satellite navigation system or an Internet Protocol system. Transmission of the data may be by cable or by radio or by satellite or optically or in any other way.

The management message generator 100 the content key provider 200 , the content encrypter 441 and the content provider 443 may be constructed in digital or analog logic, such as electronic or photonic circuitry. Depending on the circumstances, the method according to the invention can be implemented in hardware or in software. The implementation may be on a digital storage medium, in particular a floppy disk or a CD with electronically readable control signals, which may interact with a programmable computer system such that the corresponding method is executed. In general, the invention thus also consists in a computer program product with program code stored on a machine-readable carrier for carrying out the method according to the invention when the computer program product runs on a computer. In other words, the invention can thus be realized as a computer program with a program code for carrying out the method when the computer program runs on a computer.

In this case, the management message generator 100 may be implemented as a method (e.g., for execution on a digital processor), as well as the content key provider 200 as a method (e.g., for execution on a digital processor), as well as the content and management message generators 803 or the content providing and processing device 805 ,

It for example, is proprietary Services that address only to terminals to a specific security class, for example, a "B2B Service" Service for equipment of the type or security class 9. The management information, that transmit the content key, can only one security class and once the content key. It does not need parallel management information for different ones Transfer security classes to become.

In addition, can a device class or security class are defined, for. For example, "0" to which all automatically terminals belong. It can be referred to below as the base class. Service provider, also referred to as a "service provider", the the concept presented and the associated additional Management messages do not support their can Services over to handle the base class.

The presented here concept for the introduction of security classes for devices and use of different service key for one identical service refers to Digital Rights Management Systems and conditional access systems (DRM and CA systems) and supports dissemination DRM and CA systems based on open standards. diverse terminal implementations and terminal platforms lead from different manufacturers to a colorful terminal landscape. The assignment of the terminals to rudimentary Security classes and using different service keys per security class for one identical service lead to an encapsulation. This prevents the analysis from simple devices with low safety standard, an effect on the overall system Has.

Proprietary services, the for proprietary terminals are determined are also supported.

If a service provider or service provider a service with low Security requirements, he can choose the base class, the all devices are assigned automatically.

The Concept leads to no restrictions, since it's the previous business models, as described, maps. It was due to current needs develops and dissolves the problem in a lean, flexible way.

Thus, in some embodiments, secure distribution of analog or digital content, e.g. B. audio content, video content or data content allows for transmission of various media, such. B. a terrestrial round radio system, a satellite broadcasting system, an Internet broadcasting system (eg by providing content streams). Vulnerability of the secure or encrypted transmission with respect to potential cryptographic attacks is significantly reduced in some systems.

Claims (36)

Management Message Generator ( 100 ) for generating at least two message parts carrying information for decrypting a content in terminals of different security classes, comprising: an encryption device ( 103 ) for encrypting a content key ( 106 ); and a message generator ( 104 ) for generating a first message part ( 101 ) and a second message part ( 102 ), wherein the encryption device ( 103 ) is designed to store the content key ( 106 ) with a first service key ( 107 ) to encrypt a first encrypted content key ( 109 ) and the encryption device ( 103 ) is designed to store the content key ( 106 ) with a second service key ( 108 ) to encrypt a second encrypted content key ( 110 ), the first service key ( 107 ) of the second service key ( 108 ) distinguishes; and wherein the message generator ( 104 ) is adapted to the first message part ( 101 ) so that the first message part ( 101 ) the first encrypted content key ( 109 ) and a first security class identifier ( 111 ), the first service key ( 107 ), and to the second message part ( 102 ) so that the second message part ( 102 ) the second encrypted content key ( 110 ) and a second security class identifier ( 112 ), the second service key ( 108 ). Management Message Generator ( 100 ) according to claim 1, wherein the message generator ( 104 ) is designed to receive a management message ( 105 ) generating the first message part ( 101 ) and the second message part ( 102 ). Management Message Generator ( 100 ) according to claim 2, wherein the message generator ( 104 ) is designed to handle the management message ( 105 ) so that the management message ( 105 ) additionally a service identifier ( 714 ). Management Message Generator ( 100 ) according to one of the preceding claims, in which the message generator ( 104 ) is adapted to the first message part ( 101 ) so that the first message part ( 101 ) additionally a service identifier ( 714 ) and to the second message part ( 102 ) so that the second message part ( 102 ) additionally the service identifier ( 714 ). Management Message Generator ( 100 ) according to one of claims 1 to 4, in which the message generator ( 104 ) is adapted to a coding of the first message part depending on the first security class identifier ( 111 ), or where the message generator ( 104 ) is adapted to a coding of the second message part ( 102 ) depending on the second security class identifier ( 112 ) to choose. Management Message Generator ( 100 ) according to claim 1, wherein the encryption device ( 103 ) is designed to store the content key ( 106 ) with a cryptographic key ( 107 . 108 ) using an encryption algorithm. Management Message Generator ( 100 ) according to claim 6, wherein the encryption device ( 103 ) is designed to store the content key ( 106 ) using an encryption method with one of the service keys ( 107 . 108 ) to encrypt. Management Message Generator ( 100 ) according to one of the preceding claims, in which the message generator ( 104 ) is adapted to the message parts ( 101 . 102 ) add an electronic authentication or signature using a MAC message authentication method. Management Message Generator ( 100 ) according to one of Claims 1 to 8, in which the encryption device ( 103 ) is designed to receive the first encrypted content key ( 109 ) and the second encrypted content key ( 110 ) so that the first encrypted content key ( 109 ) from the second encrypted content key ( 110 ) is different. Management Message Generator ( 100 ) according to one of claims 1 to 9, in which the message generator ( 104 ) is designed to provide a first security class identifier ( 111 ) and a second security class identifier ( 112 ), different from the first security class identifier ( 111 ), the first security class identifier ( 111 ) is associated with a first class of terminals or terminals of a first device manufacturer or a first service provider, the second security class identifier ( 112 ) a second class of terminals or end is associated with devices of a second device manufacturer or a second service provider, and wherein the first class of terminals or terminals of the first device manufacturer or the first service provider has a different security standard compared to the second class of terminals or terminals of the second device manufacturer or the second service provider, the security standard indicates how easy it is for an attacker to obtain a service key contained in one of the terminals ( 107 . 108 ) to get. Management Message Generator ( 100 ) according to one of claims 1 to 10, in which the message generator ( 104 ) is adapted to the first message part ( 101 ) with a necessary part and an optional part and where the necessary part ( 710 . 712 ) the encrypted content key ( 109 . 110 ). Management Message Generator ( 100 ) according to claim 11, wherein the first security class identifier ( 111 ) is assigned to a base class of terminals and wherein the first security class identifier ( 111 ) through the optional part ( 711 ) of the first message part ( 101 ) is included. Content key provider ( 200 ) for providing a content key ( 202 for decrypting data content based on a management message ( 201 ) containing a plurality of encrypted content keys ( 204 . 205 . 206 ), the encrypted content keys ( 204 . 205 . 206 ) are assigned to different security classes, having the following features: a device for providing security class information ( 212 ) depending on a selected service type ( 213 ), the means for providing security class information ( 212 ) is adapted to a first type of service ( 214 ) a first security class ( 216 ) and a second service type ( 215 ) a second security class ( 217 ), which differ from the first safety class ( 216 ) distinguishes; a device for providing an encrypted content key ( 203 ) of the plurality of in the management message ( 201 ) contain encrypted content keys ( 204 . 205 . 206 ) depending on the security class information ( 208 ); and means for decrypting the provided encrypted content key ( 210 ) using a service key ( 211 ). Content key provider ( 200 ) according to claim 13, wherein said means for providing an encrypted content key ( 203 ) is designed to vary depending on the security class information ( 208 ) a content of a security field corresponding data field ( 204 . 205 . 206 ) of the management message ( 201 ) as the encrypted content key ( 207 ), whereby different security classes ( 216 . 217 ) different data fields ( 204 . 205 ) assigned. Content key provider ( 200 ) according to claim 13 or 14, wherein the means for decrypting the provided encrypted content key ( 210 ) is designed to vary depending on the type of service selected ( 213 ) the provided encrypted content key ( 207 ) using a first service key ( 219 ) or using a second service key ( 220 ), whereby the first service key ( 219 ) of the second service key ( 220 ), the first service key ( 219 ) the first service type ( 214 ) and the second service key ( 220 ) the second service type ( 215 ), and wherein the first service type ( 214 ) of the second service type ( 215 ) is different. Content key provider ( 200 ) according to claim 15, wherein the means for providing the encrypted content key ( 203 ), depending on the selected service type ( 213 ) for a first service type ( 214 ) a first encrypted content key ( 204 ) or for a second service type ( 215 ) a second encrypted content key ( 205 ), the first encrypted content key ( 204 ) from the second encrypted content key ( 205 ) is different. Content key provider ( 200 ) according to any one of claims 13 to 16, wherein the means for providing an encrypted content key ( 203 ) is designed to encrypt the encrypted content key ( 207 ) depending on the security class information ( 208 ) and service information ( 209 ) based on the management message ( 105 ). Content key provider ( 200 ) according to claim 17, wherein the content key provider ( 200 ) is designed to be included in the management message ( 201 ) select a message part corresponding to one of the security class information ( 208 ) corresponding security class identifiers ( 216 . 217 ) and one of the service information ( 209 ) corresponding service identifier ( 214 . 215 ) based thereon the encrypted content key ( 207 ). Content key provider ( 200 ) according to one of claims 13 to 18, wherein the means for decrypting the provided encrypt ten content key ( 210 ) is designed to encrypt the encrypted content key ( 207 ) with a cryptographic key ( 211 ) using an encryption algorithm. Content key provider ( 200 ) according to claim 19, wherein the means for decrypting the provided encrypted content key ( 210 ) is designed to encrypt the encrypted content key ( 207 ) using a decryption method with the service key ( 211 ) to decode. Content key provider ( 200 ) according to any one of claims 13 to 20, wherein the means for providing an encrypted content key ( 203 ) is designed to handle the management message ( 201 ) using a MAC message authentication method or in the management message ( 201 ) to check the electronic signature contained. Content key provider ( 200 ) according to any one of claims 13 to 21, wherein said means for providing security class information ( 212 ) is adapted to the first service type ( 214 ) the first security class ( 216 ) and the second service type ( 215 ) the second security class ( 217 ), the first security class ( 216 ) is assigned to a first class of terminals or terminals of a first device manufacturer or a first service provider, the second security class ( 217 ) of a second class of terminals or terminals of a second device manufacturer or of a second service provider, and wherein the first class of terminals or terminals of the first device manufacturer or the first service provider a different security standard compared to the second class of terminals or terminals of the second device manufacturer or the second service provider, wherein the security standard indicates how easily it is possible for an attacker to obtain a service key contained in one of the terminals ( 211 ) to get. Method for generating at least two message parts ( 101 . 102 ) carrying information for decrypting content in terminals of different security classes, the method comprising the steps of: encrypting the content key ( 106 ) with a first service key ( 107 ) to receive a first encrypted content key ( 109 ) to create; Encrypt the content key ( 106 ) with a second service key ( 108 ), a second encrypted content key ( 110 ), the first service key ( 107 ) of the second service key ( 108 ) distinguishes; Generating the first message part ( 101 ) such that the first message part ( 101 ) the first encrypted content key ( 109 ) and a first security class identifier ( 111 ), the first service key ( 107 ) is associated; Generating the second message part ( 102 ) such that the second message part ( 102 ) the second encrypted content key ( 110 ) and a second security class identifier ( 112 ), the second service key ( 108 ). Method for providing a content key ( 202 for decrypting data content based on a management message ( 201 ) containing a plurality of encrypted content keys ( 204 . 205 . 206 ), the encrypted content keys ( 204 . 205 . 206 ) different security classes ( 216 . 217 ), the method comprising the steps of: providing security class information in dependence on a selected service type, wherein a first type of service ( 214 ) a first security class ( 216 ) and a second service type ( 215 ) a second security class ( 217 ), which differs from the first security class ( 216 ) distinguishes; Providing an encrypted content key ( 207 ) of the plurality of in the management message ( 201 ) contain encrypted content keys ( 204 . 205 . 206 ) depending on the security class information ( 208 ); and decrypting the provided encrypted content key ( 207 ) using a service key ( 211 ). Content and Management Message Generator ( 803 ) for generating an encrypted content ( 442 ) with a content key ( 430 ) is encrypted, and a management message ( 432 ) containing the content key (s) associated with the encrypted content ( 109 . 110 ) in encrypted form, and the information for decrypting the encrypted content ( 442 ) in terminals of different security classes, with the following features: a content encryptor ( 441 ) for generating the encrypted content ( 442 ); and a management message generator ( 100 ) for generating at least two message parts ( 101 . 102 ) of the management message ( 105 ) according to claim 1, wherein the content encrypter ( 441 ) is designed to encrypt the encrypted content ( 442 ) by generating the content ( 440 ) of a service with the content key ( 430 ) and the management message ( 432 ) of the administrative news producer ( 100 ) generated message parts ( 101 . 102 ). Content providing and processing device ( 805 ) for providing a content key ( 434 ) from a plurality of encrypted content keys ( 204 . 205 . 206 ), to decrypt a content ( 440 ) with the content key ( 434 ) and for further processing of the content ( 440 ), the encrypted content keys ( 207 ) different security classes ( 111 . 112 ), with the following features: a content key provider ( 200 ) for providing the content key ( 434 ) according to any one of claims 13 to 22; a content provider ( 443 ) for providing a content ( 440 ); a further processing device ( 808 ) for further processing of the content ( 440 ), the content provider ( 443 ) is designed to provide encrypted content ( 442 ) with the content key ( 434 ) and decrypt the decrypted content ( 440 ) of the further processing device ( 808 ). Method for generating an encrypted content ( 442 ) with a content key ( 430 ) is encrypted, and a management message ( 432 ), which are the same with a plurality of service keys ( 420 ) encrypted content key ( 109 . 110 ) and the information for decrypting the encrypted content ( 442 ) in terminals of different security classes, the method comprising the steps of: generating the encrypted content ( 442 ) by the content ( 440 ) of a service with the content key ( 430 ) is encrypted; and generating at least two message parts ( 101 . 102 ) according to any one of claims 1 to 12. Method for providing a content key ( 434 ) from a plurality of encrypted content keys ( 204 . 205 . 206 ), to decrypt a content ( 440 ) with the content key ( 434 ) and for further processing of the content ( 440 ), the encrypted content keys ( 207 ) different security classes ( 111 . 112 ), the method comprising the steps of: providing a content key ( 434 ) according to any one of claims 13 to 22; Provide content ( 440 ) by encrypting the content ( 442 ) with the provided content key ( 434 ) is decrypted and provided; and further processing of the content ( 440 ). System ( 800 ) for the secure distribution of information between a service provider ( 801 ) and a service user ( 802 ) comprising: a content and management message producer ( 803 ) according to claim 25, adapted to receive content from the service provider ( 801 ) to recieve; a content providing and processing device ( 805 ) according to claim 26, which is adapted to communicate the content to the service user ( 802 ) to process further; and a transmission device ( 804 ) between the content and management message generator ( 803 ) and the content providing and processing device ( 805 ), so that the service user ( 802 ) the output signal of the transmission device ( 804 ), the content and management message generator ( 803 ) is designed to consist of a content ( 440 ) a service of the service provider ( 801 ) an encrypted content ( 442 ) and information for decrypting the encrypted content obtained by a security class assigned to the service and a terminal of the service user ( 111 . 112 ), in a management message ( 432 ) to create; and wherein the content providing and processing device ( 805 ) is designed to handle the content ( 440 ) of the service on the further processing device ( 808 ) of the terminal of the service user ( 802 ) to process further. System ( 800 ) according to claim 29, wherein the transmission device ( 804 ) is designed as a digital audio broadcasting system or a digital video broadcasting system or a mobile radio communication system or a satellite navigation system or an internet protocol system. System ( 800 ) according to claim 29, wherein the content providing and processing device ( 805 ) to be part of a mobile phone or a personal digital assistant device or a portable or built-in navigation device or a computer or a satellite receiving device for digital multimedia reception or a cable receiving device for digital multimedia reception. System ( 806 ) for encrypted transmission of a content key, wherein the encryption mechanism of a content key ( 430 ) assigned security class ( 111 . 112 ), with the following features: a management message producer ( 100 ) according to any one of claims 1 to 12; a content key provider ( 200 ) according to any one of claims 13 to 22; and a management message transmission device ( 807 ) between the management message generator ( 100 ) and the content key provider ( 200 ), so that the content key provider ( 200 ) the output signal of the management message transmission device ( 807 ) is supplied. System ( 806 ) according to claim 32, in which the management message transmission device ( 807 ) is designed as a digital audio broadcasting system or a digital video broadcasting system or a mobile radio communication system or a satellite navigation system or an internet protocol system. System ( 806 ) according to claim 32, wherein the content key provider ( 200 ) to be part of a mobile phone or a personal digital assistant device or a portable or built-in navigation device or a computer or a satellite receiving device for digital multimedia reception or a cable receiving device for digital multimedia reception. System ( 800 ) according to claim 29 or system ( 806 ) according to claim 32, which is designed according to one of the standards OMA, ISMA or ETSI EUROCRYPT. Computer program with a program code for executing the Method according to one the claims 23, 24, 27 or 28 if the computer program is on a machine running.