DE102009014919A1 - Method for authenticating user to system e.g. automated teller machine, involves comparing compressed recording value with stored recording value so that access to secured function is denied based on correlation of values - Google Patents

Abstract

The method involves acquiring biometric data (D) of a user by a reading device (2). Check is made whether the biometric data of the user correlate with stored biometric data, and access for the user to the system is permitted depending on the correlation result. A compressed recording value (K) is computed from the biometric data of the user, where the compressed recording value is formed as a hash value. The recording value is compared with a stored recording value so that the access to the secured function is denied based on the correlation of the compressed recording values. An independent claim is also included for a device for authenticating a user to a system, comprising a control device.

Description

The The invention relates to a method for authenticating a user on a system, wherein biometric data of the user in a reading device be captured, the biometric data of the user with stored Biometric data checked for compliance so that, depending on the comparison result allows the user access to a secure function of the system becomes.

Further The invention relates to a device for authenticating a User on a system with a reader for capture of biometric data of the user, a control device using the reading device is connected via an interface and the means for comparing the reading means having obtained biometric data with stored biometric data, so that depending on the comparison result a Access to a secure feature of the system allowed or denied and a biometric database for storing biometric data Majority of users.

From the EP 0 956 818 B1 For example, a method and a device for authenticating a user is known in which the identification of a user is based on the acquisition of biometric data of the same in a reading device. The biometric pattern for the biometric data may be a fingerprint, voiceprint, hand geometry, retinal image, or iris scan of the user. In order to authenticate the user, the biometric data of the user he is currently reading are checked for correspondence with biometric data stored in a database of the authentication device. If it has been determined in a computing device that the currently recorded biometric data of the user match the stored biometric data, access to a secure function, for example the transfer of a cash amount at an ATM, is permitted.

at the comparison between the currently determined biometric data and the stored biometric data must be taken into account that, for example, in fingerprints due to different Arrangement of the fingers on a scanner plate of the laser device different Fingerprint data available. These fingerprint data contain characteristic Characteristics of the fingerprint, such as minutia, with corresponding stored reference data are compared. In which Comparison must have a degree of overestimation (number of matches) between the recorded biometric data and the stored biometric data (reference data) exceed a predefined threshold, so that the User is identified as a valid user. The higher the predefined threshold is set, the larger is the probability that, on the one hand, due to different Fingerprint captures a valid user's access to the secured function is denied and another Fraudster is detected with manipulated fingerprint data. If the predefined threshold is set lower, the probability is greater that a valid user is detected will, however, that a fraudster wrongly access is granted. It can be seen that at the Implementation of an authentication process always a consideration must be done between the security requirement, scammers to allow no access, and the comfort requirement, valid User not to refuse. Another problem with biometric Authentication systems, between valid users and to distinguish fraudsters, it follows that the fraudster by listening to or recording the Biometric data transmission of a valid user between the reading device and the control device in the possession get the biometric data of the valid user can. These are the original ones by the reading device captured biometric data, the unencrypted to the controller be passed on. Would these "copied" biometric data fraudulently for access to one secured function would be used as part of the match comparison with stored biometric data exceeded the predefined threshold and thus an access of the fraudster to the secured Function allowed.

task The present invention is therefore a method and a Developing a device for authenticating a user such that with little effort the manipulation attempt of a user who is in the possession of biometric data of a valid user, ward.

to Solution of this problem is the invention Method in conjunction with the preamble of the claim 1 characterized in that from the biometric data of the user a compressed recording value is calculated, which is stored with Compressed recording value is compared, and in accordance with the access to compressed entry values to the secured function is denied.

To solve the problem, the device according to the invention in conjunction with the preamble of claim 6 is characterized in that a recording database for storing each of the detected in the reading device Biometric data of user-defined compressed capture values, means for calculating the compressed capture values from the biometric data of the user, means for comparing the compressed capture values obtained from the biometric data currently acquired by the reader with the number of compressed capture values stored in the capture database, and means for generating a refusal signal, if any no match is found between the currently determined acquisition value and a stored one.

Of the particular advantage of the invention is that simple Way a tampering attack, due to the spying of biometric data acquired in a reader of an access system takes place, can be detected and repelled. According to the invention it is provided that from detected by means of a reading device Biometric data (raw data) of a valid user a compressed one Recording value is generated in addition to the system is stored. This compressed recording value is unique in compressed form the biometric data recorded in the reading unit the user again. The compressed recording value contains or thus takes into account all essential and non-essential Characteristics of the biometric data of the reading device User. A manipulation attempt is then according to the invention detected if from the currently collected biometric data of the user a compressed recording value is calculated, which already has one stored compressed recording value is identical. this will as a significant indication that it is in the current biometric data currently recorded by the reading device fraudulent biometric data that are fraudulent should be used. The invention makes use of this, that usually the detected by the reading device Biometric data (raw data) of the user always differ. This also applies to biometric data of a single user. Different biometry data (raw data) are already recorded, if the same user, for example, a fingerprint the Finger in a different angular position on the scanning disc the reading device positioned. By doing that from the biometric Raw data is formed a compressed recording value, the memory requirements be substantially reduced for this test. Unlike the actual review to match the biometric data in the context of a Identification procedure in which the current biometric data with stored referencing biometric data of valid Users are compared, this is preferably additional Tamper Defense required at every Authentication of a user another compressed recording value is generated and stored. The number of compressed shot values thus increases proportionally with the number of authentication operations at.

To a preferred embodiment of the invention takes place the test, whether a compressed recording value of the user matches a stored compressed recording value, at the beginning of the authentication process and thus before the actual match comparison with the stored referencing biometric data. The manipulation attempt can thus be recognized relatively quickly, access to the secured Function denied and possibly triggered a silent alarm become.

To a development of the invention is the compressed recording value by a predetermined mathematical function of the acquired biometric data determined by the user. The compressed recording value thus represents a unique assignment to a relatively high set of values contained Biometric data.

To a development of the invention is the compressed recording value is formed as a hash value formed by a hash function. Advantageously, a standardized hash function can be used which are based on an n-bit block encryption algorithm (for example DES, DSS). For example, the hash function MD4 (message digest 4) of a size of 128 BIT or hash function SHA-1 with one size be used by 160 BIT. The hash value has a fixed value Length and is unique.

Further Advantages of the invention will become apparent from the other dependent claims.

One Embodiment of the invention will be described below explained in more detail in the drawings.

It demonstrate:

1 a block diagram of a device according to the invention for authenticating a user,

2 an association table of acquired biometric data and associated compressed acquisition values related to users and

3 a flowchart of an authentication test according to the invention.

A method according to the invention for authenticating a user can be used in systems with a secure function, for example in computer systems, POS systems, safes, cash tomatoes, cash dispensers or other end devices. An inventive device 1 Authenticating a user essentially comprises a reader 2 for capturing biometric data D of a user B and a control device 3 for processing the acquired biometric data D and performing an authentication process.

The reading device 2 For example, it can be designed as a fingerprint reader, by means of which fingerprint data can be acquired as biometric data D. Alternatively or additionally, the reading device 2 also be designed for detecting a face, a voice, a hand geometry, a retina image, iris scanner or the like. The control device 3 is a biometric database 4 associated, are stored in the respective valid users associated biometric data D as reference data R. The reference data R are determined by extraction from the biometric data D and contain the biometric features characterizing the respective user (Minutie), which are checked with corresponding reference data of the currently determined biometry data D of the user B for agreement within an identification procedure. For this purpose, the Steuereinrich device 3 comprising a microcontroller and / or a microprocessor, means for comparing the reading means 2 obtained biometric data D with the stored biometric data D and stored reference data R ₁ , R ₂ , ... R _m on. This comparison is made in the context of a main program 5 in which the identification routine (identification procedure) expires and, depending on the result of the comparison, allows or denies the user B access to the secure function of the system.

Preferably, for the comparison on the one hand, the current biometric data D of the user B in the reading device 2 detected, and in the control device 3 from this biometric data D generates a biometric data set R. This current biometric data set R is compared with the reference biometric data or reference biometric data sets R ₁ , R ₂ ,... R _m , which are in the biometric database 4 are stored, checked for compliance. If the comparison result exceeds a predetermined threshold value (match threshold), an access signal is generated so that the currently audited user is recognized as an authorized user and is granted access to the secure function. If the match score is less than the predetermined threshold, a deny signal is generated which does not allow the current user access to the secured feature. He is thus rejected. This known per se identification routine forms the main program 5 , which is a preliminary examination program 6 temporally upstream. Only when the pre-examination program 6 is completed without a denial signal has been generated, the main program closes 5 at.

In the preliminary examination program 6 will be the same actual biometric data D used in the reading device 2 according to step 7 in 3 have been recorded. From the biometric data D of the user B are transmitted after the same from the reading device 2 to the controller 3 via an interface 8th , For example USB interface, from the current biometric data D of the user B calculated a compressed recording value K, which uniquely identifies the current biometric data D (raw data) of the user B. In the control device 3 For this purpose, an arithmetic unit is integrated which determines the compressed recording value K using a mathematical function or an algorithm. For example, as a mathematical function a hash function, such as MD4, SHA-1 can be selected, so that for each recording of the reading device 2 a unique compressed recording value K characterizing this recording is formed which has a fixed length of, for example, 128 BIT or 160 BIT.

The control device 3 is a recording value database 9 assigned, in which the obtained from the acquired biometric data D compressed recording values K ₁ , K ₂ , ... K _{n are} stored. The number of compressed recording values K ₁ , K ₂ ,... K _n coincides with the number of readings by the reading device 2 recorded biometric data D1, D2, Dn. How out 2 It can be seen that a plurality of compressed acquisition values K ₁ , K ₄ , K ₈ can be assigned to a first user B1. This depends on the number of authentication processes that the first user B1 has undertaken. Is it the device 1 to a cash dispenser, with each cash dispensing operation, another compressed recording value K would be generated and stored.

How out 3 can be seen, after detecting the current biometric data D of the user B according to step 7 from these data the currently compressed recording value K is calculated, see step 10 , Subsequently, a comparison is made according to step 11 , Provides the comparison between the current compressed recording value K and that in the recording database 9 stored compressed recording values K ₁ , K ₂ , ... K _n no match, it is interpreted that there is no manipulation attempt. The current user B is considered as a provisionally valid user, the currently calculated compressed recording value K is in the record database 9 as further value K _n stored, see step 13 , Subsequently, by the expiration of the identification routine according to the main program 5 the actual identity check of the user B.

Would be made by a fraudster manipulation attempt in which by spying on the interface 8th Biometric data D of the user B have been brought into the possession of the fraudster and in which this biometric data D below the reading device 2 would be given in step 10 the same compressed acquisition value K can be calculated, which was previously according to step 13 as part of a successful identification routine 5 by a valid user B in the ad database 9 would have been saved. In the case of manipulation, the comparison would be 11 determine a match of the current value K with one of the previously stored values K ₁ , K ₂ , ... K _n , so that the authentication process is completed and according to step 12 a denial signal would be generated.

How out 2 It can be seen that the storage requirements for the data required for authentication are relatively small. In addition to the reference data R ₁ , R ₂ , R ₃ , ... R _m , each of which has been determined based on the user's original biometric data D1 of the user B ₁ , B ₂ ,... B _{n of} the user, only the compressed recording values K are determined ₁ , K ₂ , ... K _n by the reading device 2 recorded biometric data D ₁ , D ₂ , ... D _n stored. The of the reading device 2 detected biometric data D ₁ , D ₂ , ... D _{n of} the user B ₁ , B ₂ , ... B _n can be finally discarded after completion of the authentication process, since only the current biometric data D and the reference data R ₁ , R ₂ , R ₃ , ... R _m are used.

How out 3 is apparent, the authorization process would after the acquisition of the biometric data D of the user B in the reading device 2 the pre-examination program 6 and depending on the result of the pre-screening program 6 the main program 5 run through. In the preliminary examination program 6 becomes in the first step 10 from the currently detected biometric data D of the user B, the compressed recording value K in the control device 3 calculated. In a further step 11 the comparison of the currently calculated recording value K with that from the recording value database is performed 9 provided stored compressed recording values K ₁ , K ₂ , ... K _n . If a match is found, in step 12 the denial signal is generated, which prevents user B1's access to the secured function. Such a match would occur, for example, if by a fraudster at the interface 8th an attack on the biometric data D of the user B would have been done by recording or listening. This attack can be done by hardware or software that has been illegally injected into the system. Would the fraudster then using this spied biometry data D of the user B ₁ , which previously as a compressing ter recording value K ₈ in the recording database 9 have been stored, undertake a manipulation attempt and doing this corresponding biometric data D of the reading device 2 make available, this manipulation attempt would be recognized because of the biometric data D of the user B ₁ determined compressed recording value K ₈ matches the stored compressed recording value K ₁ . How out 2 It can be seen that with each valid authorization process further biometric data D _n and compressed acquisition values K _{n are} generated. Preferably only the compressed recorded values K _n are stored. In a given period of time, for example, the compressed recording values K ₁ , K ₄ and K _{8 are} stored for a first user B _{1, and} the recorded values K ₂ , K ₉ for a second user B ₂ .

1

contraption

2

reader

3

control device

4

Biometric database

5

main program

6

preliminary program

7

step

8th

interface

9

Recording values Database

10

step

11

step

12

step

13

step

B

user

D

biometric data

K

intake Level

R

reference data

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0956818 B1 [0003]

Claims (12)

A method for authenticating a user to a system, wherein biometric data of the user is acquired in a reading device, the biometric data of the user with stored biometric data is checked for conformity so that, depending on the comparison result, the user is allowed access to a secure function of the system, characterized in that from the biometry data (D) of the user (B) a compressed acquisition value (K) is calculated, which is compared with stored compressed acquisition value (K ₁ , K ₂ , ... K _n ), where the opposite compressed recording values (K, K ₁ , K ₂ , ... K _n ) denied access to the secure function. A method according to claim 1, characterized in that upon detection of a mismatch of the opposing compressed recording value (K, K ₁ , K ₂ , ... K _n ) an identification procedure ( 5 ) within which the current biometric data (D) of the user (B) is compared with the stored biometric data (R ₁ , R ₂ , ... R _m ) using at least one predetermined match threshold. Method according to claim 1 or 2, characterized in that in the identification procedure ( 5 ) from the current biometric data (D) of the user (B) a biometric data set (R) is extracted, which is compared with a reference biometric data set (R ₁ , R ₂ , ... R _m ) to match. Method according to one of claims 1 to 3, characterized in that the compressed absorption value (K) by a given mathematical function from the biometric data (D) of the user (B) is formed. Method according to one of Claims 1 to 4, characterized in that the compressed recording value (K, K ₁ , K ₂ , ... K _n ) is formed by a hash function from the biometric data (D). A device for authenticating a user to a system comprising - a reading device for acquiring biometric data of the user, - a control device which is connected to the reading device via an interface and which has means for comparing the biometric data obtained by the reading device with stored biometric data, then that, depending on the result of the comparison, access to a secure function of the system is allowed or denied, - a biometric database for storing biometric data of a plurality of users, characterized by - a retrieval database ( 9 ) for storing in each case in the reading device ( 2 ) recorded biometric data (D) of the user (B) characterizing compressed recording values (K), - means for calculating the compressed recording values (K) from the biometry data (D) of the user (B), - means for comparing the currently selected by the Reading device ( 2 ) recorded biometric data (D) compressed recording value (K) with the number of in the ad data ( 9 ) Stored compressed recording values (K _1, K _2, ... K _n), and - means for generating a refusal signal, if a match between the recording currently determined value (K) and a stored compressed recording value (K, K _1, K _2, ... K _n ) is detected. Device according to claim 6, characterized in that that the compressed recording value (K) by applying a mathematical Function on the biometry data (D) of the user (B) can be generated are. Device according to claim 6 or 7, characterized the compressed recording value (K) is formed as a hash value is. Device according to one of claims 6 to 8, characterized in that the biometric database ( 4 ) comprises a number of different reference users (B ₁ , B ₂ , ... B _m ) and extracted from the biometric data (D) reference biometric data sets (R ₁ , R ₂ , ... R _m ). Device according to one of claims 6 to 9, characterized in that the comparison between the currently detected by the reading device biometry data (D) of the user (B) with the in the biometric database ( 4 ) stored biometry data (R ₁ , R ₂ , ... R _m ) in a separate identification procedure ( 5 ) is integrated. Device according to one of claims 6 to 10, characterized in that a match signal can be generated if a number of matches between the in the reading device ( 2 ) recorded biometric data (D) of the user (B) on the one hand and in the biometric database ( 4 ) stored reference biometric data (R ₁ , R ₂ , ... R _m ) exceeds a predetermined threshold. Device according to one of claims 6 to 10, characterized in that the control unit ( 3 ) is integrated in a terminal, in particular in a computer or in a POS system or in an ATM or in a vault.