CN1169805A - Laser Disk Programmable Read-Only Memory - Google Patents

Abstract

Data on a CD-PROM disk is selectively accessed in a secure manner by selectively encoding binary digital passwords and decryption keys onto the same disk in a separate area. Passwords (66) and decryption keys (65) may be programmed onto the disk after manufacture, such as at the point of sale, by selectively obliterating the readability of bits in addressable sectors. A binary digital key is then later recognized as the result of a string of addressable sectors, with the readable and unreadable sectors providing the digital string. In an embodiment, a manufacturer may place several or all versions and features of a large program on a single CD-ROM, encrypted, and later provide keys to enable (66) only selected ones of the features and versions for retrieval. By programming a password or decryption key over an area of a programming region having a storage capacity of at least a megabyte, and in some cases several megabytes, existing methods of intercepting and defeating such security schemes may be defeated.

Description

Laser Disk Programmable Read-Only Memory

The technical field of the present invention

This invention relates to laser disc read only memory (CD-ROM) discs, and more particularly to programmable access control of data on such discs.

Background Art of the Invention

This application is a continuation-in-part of US Patent Application Serial No. 08/097,767, the contents of which parent application is hereby incorporated by reference.

Laser Disk ROMs are an extension of Audio Compression Disk, the music industry's high-quality disk technology. A conventional laser disk ROM with a disk diameter of only about 12 cm (4 3/4 inches) can store the contents of 250,000 pages of text documents, or the contents of 1,500 floppy disks, or 74 minutes of audio signals, or thousands of images . Computer-controlled laser disk ROM players can retrieve the content within seconds. Laser disk ROM products are used by people in many fields, such as library science, education, publishing, Internet data services, government, banking, insurance, legal, entertainment, and medical sectors.

Laser disk ROMs are read from the inside out through only one spiral track, about 4.827 kilometers (3 miles) long. The data on a track is divided into sectors, each sector is equal in length and contains the same amount of information as well as an absolute address. Figure 1 shows the standard data format, in this format, each sector 13 on the laser disk read-only memory 11 has 2,352 bytes of information, including 12 bytes of synchronization information, 4 words Section identification, 288 bytes of error correction code and 2,048 bytes of data.

Laser disk read-only memory master disks are made by using a high-power laser to form a series of tiny pits on a blank surface with a spiral track. The shape and length of the pits along the track represent the digital information to be recorded. The original blank disk is used to make the master disk, which is usually molded and replicated from a resistive material, resulting in the familiar laser disk ROM. The pattern of the master disc is replicated on the surface of the polymer substrate, which then forms a replica of the original disc. The replica with the indicia is coated with a highly reflective material, usually vapor deposited aluminum, and a protective coating is applied over the reflective film.

Early laser disk ROMs contained digitized analog information and were primarily designed to be used with limited playback user controls and linear formats. Other laser disk ROMs are programmed to take advantage of the player's microprocessor and limited internal memory.

To read data from a LaserDisk ROM, the drive in the LaserDisk ROM player changes its rotational rate so that the disk's rotational speed slows down as sectors move away from the center of the disk. As the disk is spinning, a low-powered laser read head is focused on the helical track through the thickness of the polymer disk. And the reflected light is detected by a light detector, thereby converting the presence or absence of a pit into an electrical signal that is interpreted by a computer as digital data. The laser read head views the pits from the opposite side from which the pits were created, thus viewing a pit as a bump relative to the laser source.

When the laser reading head hits the pitted surface, the focused laser light is scattered so much that the light reflected near the photodetector is blurred. On the other hand, when there are no pits, more light is reflected near the photodetector.

FIG. 2 shows a series of pits formed on the surface of the laser disk ROM 31. As shown in FIG. Surface 23 is the original disc surface, while 25 represents the depth from the original surface to the penetrating pit. The figure is not to scale because the pits are almost infinitesimally small relative to the thickness of the disc. The laser reading head runs in the direction of arrow 24 .

Laser disk read-only memory, much like other high-capacity storage systems, relies on channel codes for data storage and retrieval. The channel codes used in laser disk ROMs are often referred to as 8 to 14 modulation (EFM).

In the 8 to 14 modulation system, each disc movement translates the "edge" of the passing laser beam, and the reflected light intensity changes are decoded by the master reading system to a binary "1" for the transition period 27 of the signal. Whereas binary "0"s occur everywhere else, the number of "0"s between "1" transitions is a function of the surface spiral track length between pits. During operation, the track code is converted into digital bytes and digital blocks by reference to a stored look-up table. Typical systems for encoding and decoding are known in the prior art.

A complete LaserDisk ROM file system consists of three main parts: a logical format used to define the directory structure and operating characteristics of the disc through a decoder program that determines where files are found on the LaserDisk ROM directory, how the directory is structured, and how to perform error correction on the disk data; the initial program for writing data on the disk according to the logical format; and the destination program, which is to read and understand the logical format and use it to Files on read memory provide access, as well as components for reading and translating data structures.

Most LaserDisk ROMs have their own operating systems that respond to calls from file managers used exclusively by LaserDisk ROMs. The Laser Disk ROM also includes its own decoding routines that define the location of the sectors so the computer knows where to find the stored data. These retrieval decoders usually have a menu interface on the computer. A laser disk ROM program usually requires 640K bytes of computer memory to run, and its storage address can be allocated to the data access driver and the destination program on the computer hard disk.

Almost all existing LaserDisk ROMs and LaserDisk ROM players use the so-called High Sierra standard or the recently upgraded ISO9660 standard. Connections between laser disk ROM players and computers have also been standardized. Laserdisk ROM players typically interface to computers using a Small Computer System Interface (SCSI).

Laser disk ROMs appear to be a reasonable and convenient device with reasonable market prospects for large applications rather than commercial use using large numbers of floppy disks. They can easily provide enough space for a low cost. In mass production, the price is around $0.50 per disc. Laser disk ROM drives will also become more affordable.

While having clear advantages, there are some serious drawbacks in using laser disk ROMs to capture the market for large applications. The biggest problem is that there is no reliable way and mechanism to record various information and characteristics on a disc, but only certain parts of it can be used by specific consumers.

Another existing problem is the lack of satisfactory copy protection for laser disk ROMs. Laser disk ROMs are usually shipped for sale with a floppy disk containing data access drivers and object programs that must be installed in the user's computer to run the laser disk ROM. The floppy disk is copy-proof, but the laser disk ROM is not. This method of protection works extremely poorly compared to the copy protection normally used for floppy disks. The contents of the laser disk ROM can be copied to the hard disk, and the floppy disk protection mechanism can be deciphered by any optional copying program.

For example, multi-application packages like Ethernet, Windows, AutoCad, and other types have always come with multiple floppy disks. Many of these programs vary from 20 to 40 floppy disks to install a complete program on a mainframe.

What is needed is a device that allows a retailer of disparate and large applications to record a complete application on a laser disc ROM and selectively allow storage of data portions at the time of purchase. Pick. There is also a need for a device capable of copy-protecting laser disk ROMs so that floppy disks are no longer the only copy-protection tool. With these improvements, retailers can mass-produce at low cost a program with a complete product version on a laser disk ROM, make the laser disk ROM copy-proof, and selectively control its use Use of the Program. A user who only needs to make a one-time purchase of the basic software package on a disc can access other applications on the disc as long as he pays the retailer the required fee.

Summary of the invention

According to one embodiment of the present invention, there is provided a kind of method that host computer provides data and carries out data retrieval in laser disk read-only memory in a kind of safe way, and this method comprises the following steps: (1) store data in production process; and (2) programming a password into the Laser Disk ROM after fabrication of the Laser Disk ROM by modifying selected sectors on the Laser Disk ROM to make conventional Laser-readable control programs The sector could not be read. The sequence of numbers comprising the password is a sequence of numbers identified by a series of readable and unreadable sectors. The password is characterized in that it can be programmed in a programmable area of a laser disk read-only memory with a data storage capacity of at least one megabyte area large enough to enable existing interception programs and interception mechanisms invalid.

In some cases, the data to be read can avoid being recorded by means of an encrypted password and the password is the key for decoding.

According to another aspect of the invention, a large program with multiple features and versions can be placed on a laser disk ROM, and can be stored on the disk by programming preselected passwords and/or decryption keys on the disk. Selected parts are allowed at the point of sale.

Brief description of the drawings

Fig. 1 is the accessible sector content in a sector on the laser disk read-only memory of the prior art;

Figure 2 is a cross-sectional view of a track on a prior art laser disk ROM, showing pits for bit transitions;

3 is a plan view of a laser disk programmable read-only memory according to one embodiment of the present invention, showing data storage and programming areas;

4A is a projection view of a programming device according to an embodiment of the present invention;

Figure 4B is an enlarged illustration of the internal components of the programming device of Figure 4A;

Figure 4C is a cross-sectional view of a laser disk read-only memory located within the programming device of Figures 4A and 4B, showing a focused laser beam within the device;

Figure 5 is an illustration of the content of a password as a decryption key according to one embodiment of the present invention; and

FIG. 6 is a flowchart representing steps in a method of decrypting data according to one embodiment of the invention.

Detailed description of the invention

The invention is named Laser Disk Programmable Read Only Memory (CD-PROM). In one aspect, the present invention provides a device for selectively enabling data on a laser disk ROM after mastering and embossing, but before delivery to the end user. A conventional laser disk ROM has a data storage capacity of approximately 600 megabytes. Some of these bytes are allocated to the disk's operating system. Typically, large applications (such as Windows, Ethernet, and Autocad) require less than 100 megabytes of real memory. This leaves 500 megabytes of memory reserved for data access and other programming.

One aspect of the present invention relates to encoding a laser disk programmable read only memory into a digital format including encoded passwords allowing access to selected data on the laser disk by a dedicated laser programming device.

FIG. 3 is a plan view of a laser disk PROM 31 according to an embodiment of the present invention. A small area 33 near the inner opening 32 is allocated to the operating system of the disk. The operating system is automatically loaded into a host computer when the disk is placed on a drive attached to the CD player (here it is assumed that the computer's control system already has the drive configured). Area 35 of the disk occupies approximately 100 megabytes, which is used for data storage. All application-related data can be stored in this area H. All features and versions of programs such as Autocad can be stored in area 35, for example. The size of area 35 is variable, depending on the application.

All data in area 35 is encrypted. Various encryption methods exist, such as reverse Arabic characters, letter replacement, word conversion, number/letter replacement, and various combinations of these and other methods.

The remainder of the laser disk PROM is area 37, which can be up to 500 megabytes of programmable area. The login and programming of passwords takes place in this area. Means are provided in the programming area 37 to allow different parts of the data area 35 .

Figure 4A is a perspective view of a laser programming device according to one embodiment of the present invention. External device 39 may be a device that looks like a conventional laser disk read only memory. In this embodiment, it may have a tray 41 for receiving a laser disk ROM 34 , an open/close drive 43 , and a built-in switch 45 . In this embodiment, there may be other control drivers as well.

The laser programming device 39 is also like a conventional built-in laser disk ROM device, except that a laser readout unit is installed and a high power laser capable of destroying sectors on the laser disk ROM device is used. part. In addition, the laser components in device 39 are controlled to selectively destroy sectors for programming functions.

FIG. 4B is a diagram of the internal components of the laser programming device 39 . The circuitry therein is very similar to a standard laser disk ROM and is shown schematically in Figure 4B.

To operate the programming device 39, a laser disk ROM 34 is placed on the disk tray with the read side down, that is, the reflected laser light is on the opposite side of the laser device. The laser system is generally indicated at 46 and includes a laser generator, focusing elements, and tracking mechanism. The laser system is located in the vicinity of where the corresponding elements are located in the drive of the laser disc ROM.

In this embodiment, the control program operates on a host computer via a communications link to control circuitry 52 located on board to provide control operations to programming device 39 . The same control program provides a user interface on the display of the host computer, thereby allowing the operator to control and adjust the operation of the programming device 39 .

In operation, the laser beam 49 emitted from the laser generator 50 is selectively enabled when a signal is received from the host computer. In this embodiment, the laser beam 49 is focused on the spiral track of the laser disk ROM 34 through a prism 51 and an objective lens. Actuator 58 controls the focus adjustment, driver 55 rotates the laser disk ROM, and translation actuator 56 moves the laser system radially of the track so that it can follow the helical track.

FIG. 4C is an enlarged cross-sectional view of a portion of a spiral track of a laser disk ROM 34, showing the use of a focused laser beam through the thickness of the laser disk to reach the pits of the spiral track. The thickness D1 of the laser disk ROM 34 is about 1.2 mm, and the depth D2 of the recess is about 0.12 microns. The width of the tracks is typically 0.6 microns and the distance between two tracks is 1.6 microns. In this embodiment, the laser disk has a lacquer-coated surface layer 36 .

It can be seen that the magnitude of the recessed depth on the surface of the laser disk ROM is a small proportion compared to its thickness, so the recessed depth itself is quite shallow.

It is to be remembered that, given the relevant and typical dimensions above, there are at least two mechanisms that can be used to focus the energy of the laser beam 49 on the helical track without damaging the laser disk, and to The sectors selected in can be modified so that they cannot be read by conventional read mechanisms. One means is by focusing the beam 49 at a large angle (in angle A) so that the power in each cell area can be kept decreasing proportionally until reaching the track area. Another means is to choose the wavelength of the laser beam so that the disk material is laser transparent. In different embodiments of the invention, different combinations are used. In addition, a reflective layer at the track interface helps to clear the data record in selected areas, as does a portion of the laser energy to be reflected at the interface. Furthermore, it has been found that the alteration or damage caused by the laser beam 49 in the reflective layer itself is relevant to the ability to clear selected sectors.

In an embodiment of the present invention, the format of damaged or damaged and intact sectors is arranged sequentially along the spiral track in area 37 (see FIG. 3 ), thereby forming a sector that can be recognized by the operating system and stored in area 35. String of digits available when data is decoded. In general, any programmed information can be placed in selected areas on the laser disk ROM, thereby providing a laser disk ROM in accordance with a preferred embodiment of the present invention.

Passwords or other programmed data need not be allowed in a spiral sequence. There may be formats of formats, and the organization of sectors providing passwords or data for other purposes may be scattered throughout programming area 37 . There can be many passwords in a laser disk PROM, each capable of allowing a different application.

The concept of password permission in an embodiment of the present invention is shown in FIG. 5, which includes an index table 61 of passwords 63, each password generating a field 37 for permission according to the laser disk ROM of the present invention. Numeric key 65 for the selected part. The selected portion keyed by the password may be an application 66 such as Autocad or other available separate data set, as shown in FIG. 5 . Individual keywords allow individual boot features or versions of the application.

Such a password table is of course a useful mechanism for understanding the concept of option enabling of the present invention. The password table is not actually written all the way to memory. If so, it could also be copied and used to break code. Instead, the ability to discover passwords is programmed into the operating system, and the actual password is discarded once used.

A flow diagram of a password enabling function according to one embodiment of the present invention is shown in FIG. 6 . At the beginning a laser disk PROM is inserted at 67 into the disk drive. An operating system is loaded into the computer at 69 . The serial number is checked at check box 71 (at a different vendor). In this particular path, if the serial number of the license is not detected, the license process may be terminated at 73. The operating system in this embodiment then retrieves the first password for the programming area 37 at function block 75 .

When the operating system finds a password at 77, the password is sent to the decoder at 79 and used to release the data key address. The system then reads the release data at 83, typically loading the decoded data into some portion of the main system's hard drive. The password is discarded at function block 85 . The drop function does not have to be another step in the operation, it can be an automatic function of the data flow controlled by the operating system.

Control goes to 89 after all passwords have been found and the data that can be accessed has been accessed.

The "release" with a password can be as simple as allowing a range of page-ordered sectors with a starting address and a certain length to be read into memory, or it can be extremely complex. An example of a simple release mechanism is where the password gives the instruction "read every 5th sector at the beginning of a range at a particular address". Another mechanism can change the release instruction every day as needed, eg "if this is the twenty-third hour of the purpose, a predetermined number can be added to every 6th sector".

An example of a rather complicated release mechanism is as follows: The operating system looks for password number 1, that is to say an 8-digit number and finds it. The password is a key to an algorithm to be loaded that looks for another key in data area 37 in one of 24 different formats, each of which represents each hour of the purpose, which can be accessed by computer The clocks in are queued for determination. Password 2 is an actual permission key for all or any of the 24 retrieval formats. The added factor is time-based efficient retrieval with the first password, thus adding another layer that one must solve to break the system.

In another embodiment of the invention there is a means to give an enable password to a user who wants to access more applications on a laser disk PROM than he purchased. In this embodiment, the user interacts with the computer in a queue, typing in the actual password which is not required. Alternatively, the password can be appended to the CONFIG.SYS file, i.e. a keying sequence, or other password key that allows the operating system to find an existing password on the laser disk PROM, thereby freeing the application in the data area 37 program device.

Another feature lies in the internal copy protection, ie the data provided by the laser disk programmable read-only memory on the encrypted disk. The disk can be copied, but encrypted data cannot be used. Since the LaserDisk PROM is itself copy-protected, the method of providing copy protection on the accompanying floppy disk is somewhat redundant.

Due to the large capacity of the programmable area 31, the range available for programming is large. For example, the system can track the use of the address book from the use of the sold address book. An entire address book could be made on a laser disk PROM, sold with all the programs that used it to print address labels, cards, and even return addresses. These companies could charge users based on how many times the address book on the laser disk PROM was used. Programming the laser disk PROM that accompanies the operating system modifies the address book to include imaginary recipients with addresses to sellers. In this way, each time the customer uses the address book, the seller can receive a mail addressed to an imaginary recipient. This allows vendors to track together how many times the newsletter is actually used.

In another embodiment of the invention, a digital area having several hundred sectors is selected to include several megabytes of memory, and passwords are programmed in the area by destroying selected sectors on the laser disk ROM , as described above. An area of several hundred sectors extends from the first damaged sector to the last along the spiral recording track of a laser disk ROM and is considered the "protected" area. When a Laser Disk ROM is used in a host computer with a Laser Disk ROM drive, the password must be entered, as with other systems, otherwise the Laser Disk ROM cannot be read.

The efficacy of this embodiment relies on the fact that to copy data on a protected LaserDisk ROM, an "intercept" program must be used, and that program must copy the entire protected area to the host's RAM. access memory to read the data on the laser disk read-only memory. There are many practical limitations to the RAM on most computer motherboards which are also used to read the laser disk ROM, so just make sure the protected area is larger than the host's RAM complement. In some cases, it is necessary to have "good" data in undamaged sectors in such a protected area, and this is achieved by writing random data to the appropriate size at manufacturing time, where the Program by destroying selected sectors to get password.

In practice, this is typically as much as 16 megabytes on a personal computer, but the purpose of such a large amount of RAM is to be able to run fairly large operating systems, secondary systems like Windows ^™ , and even larger applications. After loading all the necessary software into the RAM, there is usually not 2-4 megabytes of storage space left in such a large RAM system for the interception program to destroy the supercomputer of the present invention. password.

A password field of 1 megabyte is enough to defeat interceptors in many existing personal computers, and a password field of 4 megabytes can defeat all interceptors with rare exceptions.

The fact that the superpassword concept of passwords is too large to be handled by existing interception procedures and techniques can also be applied to the decoding of keywords, such as described in the different embodiments above, and can also be used for multiple passwords and keys. Words, which are used for different and multiple application versions on a laser disk ROM. For example, the capacity of a recording area as shown in Figure 3 is 100 megabytes and the programming area is 500 megabytes, then a considerable amount of passwords and keywords can be programmed at the 500 megabytes area, to selectively Different parts of the same amount of data are enabled and decoded in one data area. For example, in the 500-megabyte area, 50 10-megabyte passwords and keywords can be programmed and then each extended over a 10-megabyte protected area.

It will be apparent to those of ordinary skill in the art that there are many alternatives for embodiments of the present invention. Some variations are described above. For example, provision could be made for a second level of access control to give users the option to "pay and go" to make other applications available on the laser disk PROM. Another variation is to add copy protection to the laser disk programmable read-only memory.

There are many equivalent ways, the characteristics of which have been described above. For example, the above-described embodiments can be implemented in different sized capacities, existing databases greater than 500 megabytes and databases that cannot fit on a laser disk PROM. In the present invention, the concept of monolithic laser disk programmable read-only memory involved can be extended to produce a group of laser disk programmable read-only memories, thereby accommodating additional large databases in the manner of the prior art, and on a disk Provides permission to copy protection. Another variant uses at least one 12-inch large video disk as a laser disk programmable read-only memory to store large-sized databases.

Those who are proficient in the technical field can modify and change the above-mentioned embodiments of the present invention within the scope of the present invention, and there are many equivalent solutions with respect to the above-mentioned implementations introduced as examples. The spirit and scope of the invention are protected only by the appended claims.

Claims (9)

1. A method of providing digital information on a laser disc read-only memory to a host computer in a secure manner, wherein said information is recorded in the physical structure of a recording track, said method comprising the steps : a) providing digital information in a formatted sector of a recording area on a laser disk read-only memory; and b) Program a password on the laser disk read-only memory by destroying the physical structure of the recording track of the selected sector in the programming area, thereby forming a sequence of physically destroyed and undamaged sectors, which is provided for allowing all The host computer reads out the password of the digital information in the recording area; Wherein said password is recorded on an area of said programming area, said programming area having a data storage capacity of at least 1 megabyte. 2. The method of claim 1, wherein said password is extended in a data storage area having at least 4 megabytes. 3. The method according to claim 1, wherein said data information is provided on said laser disk read-only memory in an encrypted manner, said encrypted manner requires a key for decryption, and is programmed into said The password in the programming area is recorded as a key for decrypting the encrypted digital information. 4. The method according to claim 1, wherein said digital information includes a plurality of files, each file requires a separate password to be accessed, and each password is programmed into said programming area to Different files are allowed. 5. The method of claim 3, wherein said digital information includes a plurality of encrypted files, each encrypted file requiring a separate key to be decrypted, and each key wherein is programmed into said The programming area is used to decrypt the plurality of encrypted files. 6. A method for providing access control to an individual computer file among a plurality of computer files stored on a laser disc read-only memory purchased by a user, wherein said information is recorded in a physical structure of a recording track , the method is characterized in that it comprises the following steps: a) providing individual computer files in formatted sectors of a recording area on a laser disk read-only memory; and b) programming a digital password into the programming area of said laser disk ROM, said password being used to allow access to computer files purchased by the user, by destroying the recording tracks of selected sectors in the programming area physical structure, thereby forming a sequence of physically damaged and non-destructed sectors; Wherein said password is recorded on an area of said programming area, said programming area having a data storage capacity of at least 1 megabyte. 7. The method according to claim 6, wherein said respective files are recorded in a laser disk read-only memory in an encrypted manner, and said encrypted manner requires a keyword for decryption, and said programming to the programming area The password in is the key to decrypt the encrypted digital information. 8. A laser disk read-only memory, characterized in that it comprises: a) a recording area in which digital information is stored digitally by physical structure in formatted sectors along a spiral track; and b) a programming area having formatted sectors in which a password is recorded by selectively destroying the physical structure of digital tracks in selected sectors in the programming area, thereby forming a physical A sequence of sectors, corrupted or not, providing a password for allowing access to digital information recorded in said recording area; Wherein said password is recorded on an area of said programming area, said programming area having a data storage capacity of at least 1 megabyte. 9. The laser disk read-only memory according to claim 8, wherein the digital information recorded in the recording area is recorded in an encrypted manner, and the password recorded in the programming area is a password for recording in the recording area. The key to decrypt the digital information in the zone.

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