Iris security authentication protocol based on inner product function encryption

Abstract

The invention belongs to the field of information security, and discloses an iris security authentication protocol based on inner product function encryption, and entities involved in the scheme comprise a key distribution center KGC, a user, a client and a server. The scheme is mainly divided into a registration stage and a matching stage, and the matching stage generally comprises five processes: 1, initializing an iris recognition system; 2, generating an iris data ciphertext; 3, generating an iris identification key; 4, decrypting and calculating the iris data; and 5, judging an iris recognition result. According to the iris security authentication protocol based on inner product function encryption disclosed by the invention, the original iris data and the matched iris data cannot be leaked, so that the security of iris identification authentication is improved.

Description

Technical Field

[0001] The present invention belongs to the field of function encryption technology and information security; in particular, it relates to a design of an iris security authentication protocol based on inner product function encryption in response to the need for privacy protection of biometric features in biometric feature recognition. Background Art

[0002] Inner product function encryption is a special type of function encryption that can safely calculate the inner product of two vectors without leaking any data in the two vectors while having the characteristics of function encryption. Currently, inner product function encryption is mainly used in data mining, privacy protection and machine learning.

[0003] Normalized Hamming distance is a measure of the difference between two strings of equal length, but the result is normalized (or standardized) to a certain range, usually between 0 and 1. This normalization helps to compare between strings of different lengths, or provide a uniform scale when comparing Hamming distance with other metrics.

[0004] Currently, most of the research on biometric identification is aimed at its efficiency and accuracy. The present invention aims at the security of biometric identification and the protection of biometric privacy, and realizes the combination of biometric identification and inner product function encryption. Summary of the invention

[0005] The present invention proposes an iris security authentication protocol based on inner product function encryption, which can perform iris recognition without revealing the user's iris features.

[0006] An iris security authentication protocol based on inner product function encryption includes the following steps:

[0007] Step 1: User registration; the user's original iris data is used for subsequent identification, divided into iris feature value and mask, and stored in the server after XOR encryption;

[0008] Step 2: Initialize the iris recognition system; the key distribution center KGC runs the initialization algorithm Setup to generate two pairs of master private keys and public keys, of which the two public keys are sent to the client;

[0009] Step 3: Generate iris data ciphertext; the client runs the encryption algorithm Encrypt, calculates two sets of ciphertext, and sends them to the server;

[0010] Step 4: Iris recognition key generation: The key distribution center KGC runs the key generation algorithm KeyGen, calculates two decryption keys, and sends them to the server.

[0011] Step 5: Decryption calculation of iris recognition parameters: The server runs the decryption algorithm Decrypt to calculate the recognition parameters and Hamming distance;

[0012] Step 6: Determine the iris recognition result; the server determines the recognition result and sends the determination result to the client.

[0013] Some advantages of the present invention are:

[0014] Compared with common iris recognition authentication, the present invention combines inner product function encryption with iris recognition on the premise of ensuring the recognition accuracy, thereby realizing privacy protection in biometric identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 : System flow chart of the present invention;

[0016] Figure 2 : System flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to facilitate a better understanding of the purpose, structure and function of the present invention, the following is a further detailed description of the on-chain multi-institution credit assessment method and system based on indistinguishable confusion of the present invention in conjunction with the accompanying drawings and implementation examples. It should be understood that the implementation examples described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0018] Please see Figure 1 The present invention provides an iris security authentication protocol based on inner product function encryption, and the entities involved include a key distribution center KGC, a user, a client and a server.

[0019] It is assumed that a specific implementation example includes a key distribution center KGC, a user, a client and a server.

[0020] So if Figure 2 As shown, an iris security authentication protocol based on inner product function encryption includes the following steps:

[0021] Step 1: User registration; the user's original iris data is used for subsequent identification, divided into iris feature value and mask, and stored in the server after XOR encryption;

[0022] Step 1 of the present invention is further described in detail as follows:

[0023] Step 1.1: The user uses the device to scan the iris to extract the original iris feature value X and mask M, and set two temporary keys K x and K m , where X, M, K x , K m ∈{0,1}2028 ;

[0024] Step 1.2: The user combines the original iris feature value X and mask M with two temporary keys K x and K m Perform XOR encryption, that is, S = X ⊕ K x , T=M⊕K m ;

[0025] Step 1.3: The user sends the XOR-encrypted ciphertext S and T to the server for storage.

[0026] Step 2: Initialize the iris recognition system; the key distribution center KGC runs the initialization algorithm Setup to generate two pairs of master private keys and public keys, of which the two public keys are sent to the client;

[0027] Step 2 of the present invention is further described in detail as follows:

[0028] Step 2.1: The key distribution center KGC generates two secure prime numbers of length 256 according to the security parameter λ=1024: p'=prime(λ / 4), q'=prime(λ / 4);

[0029] Step 2.2: The key distribution center KGC calculates p = 2p' + 1 and q = 2q' + 1, and determines whether p and q are large prime numbers. If so, proceed to the next step, otherwise return to step 2.1;

[0030] Step 2.3: The key distribution center KGC calculates the integer N=pq;

[0031] Step 2.4: The key distribution center KGC generates a random number Calculate g = g' 2N mod N 2 ;

[0032] Step 2.5: The key distribution center KGC generates a master private key msk consisting of a random number with a length of l = 2028 1 =(s 1,1 ,s 1,2 ,…,s 1,l ) and msk 2 =(s 2,1 ,s 2,2 ,…,s 2,l ),in

[0033] Step 2.6: The key distribution center KGC calculates the public key mpk 1 =(h 1,1 ,h 1,2 ,…,h 1,l) and mpk 2 =(h 2,1 ,h 2,2 ,…,h 2,l ),in

[0034] Step 2.7: The key distribution center KGC sends the master private key msk 1 and msk 2 And the public key mpk 1 and mpk 2 Sent to the client.

[0035] Step 3: Generate iris data ciphertext; the client runs the encryption algorithm Encrypt, calculates two sets of ciphertext, and sends them to the server;

[0036] Step 3 of the present invention is further described in detail as follows:

[0037] Step 3.1: The server sends the encrypted user's iris mask T to the client, and the client decrypts it to obtain the iris mask M = T ⊕ K m ;

[0038] Step 3.2: The client XORs the iris feature value X' to be identified to obtain the ciphertext β = X'⊕K x , where X'∈[0,1} 2028 ;

[0039] Step 3.3: Client Calculation and x 2 =(x 2,1 ,x 2,2 ,…,x 2,l ) = M·M';

[0040] Step 3.4: The client generates two random numbers

[0041] Step 3.5: Client Calculation and

[0042] Step 3.6: Client Calculation

[0043] Step 3.7: The client sends the ciphertext ct 1 =(ct 1,0 ,x 1,1 ,…,x 1,l ) and ct 2 =(ct 2,0 ,x 2,1 ,…,x 2,l ) is sent to the server.

[0044] Step 4: Iris recognition key generation: The key distribution center KGC runs the key generation algorithm KeyGen, calculates two decryption keys, and sends them to the server.

[0045] Step 4 of the present invention is further described in detail as follows:

[0046] Step 4.1: The server calculates two decryption vectors and 2 =(y 2,1 ,y 2,2 ,…,y 2,l )=(1,1,…,1), sent to the key distribution center KGC;

[0047] Step 4.2: The key distribution center KGC calculates two decryption keys and

[0048] Step 4.3: The key distribution center KGC will decrypt the key sk y1 and sk y2 Send to the server.

[0049] Step 5: Decryption calculation of iris recognition parameters: The server runs the decryption algorithm Decrypt to calculate the recognition parameters and Hamming distance;

[0050] Step 5 of the present invention is further described in detail as follows:

[0051] Step 5.1: Server-side calculation and

[0052] Step 5.2: The server calculates the decryption result and

[0053] Step 5.3: The server calculates the Hamming distance

[0054] Step 6: Determine the iris recognition result; the server determines the recognition result and sends the determination result to the client;

[0055] Step 6 of the present invention is further described in detail as follows:

[0056] Step 6.1: The server identifies the parameter d 2 And the Hamming distance NHD judgment, if NHD < τ and d 2 >η, it proves that the two sets of iris data are taken from the same iris, where τ and η are NHD and d 2The threshold determines the accuracy of recognition and the security of the protocol. In the protocol, both are fixed and the specific value needs to be set after testing the iris feature extraction algorithm used in advance.

[0057] Step 6.2: The server sends the judgment result to the client.

[0058] The present invention implements a delegable inner product function encryption method based on the inner product function encryption algorithm. The scheme can realize controllable sharing of decryption authority under the premise of maintaining the security of inner product encryption.

[0059] It should be understood that parts not elaborated in detail in this specification belong to the prior art.

[0060] It should be understood that the present invention is described by some embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all fall within the scope of the claims of the present application.

Claims

1. An iris security authentication protocol based on inner product function encryption, characterized in that: The following steps are involved: Step 1: User registration; the user's original iris data is used for subsequent identification, divided into iris feature value and mask, and stored in the server after XOR encryption; Step 2: Initialize the iris recognition system; the key distribution center KGC runs the initialization algorithm Setup to generate two pairs of master private keys and public keys, of which the two public keys are sent to the client; Step 3: Generate iris data ciphertext; the client runs the encryption algorithm Encrypt, calculates two sets of ciphertext, and sends them to the server; Step 4: Iris recognition key generation: The key distribution center KGC runs the key generation algorithm KeyGen, calculates two decryption keys, and sends them to the server. Step 5: Decryption calculation of iris recognition parameters: The server runs the decryption algorithm Decrypt to calculate the recognition parameters and Hamming distance; Step 6: Determine the iris recognition result; the server determines the recognition result and sends the determination result to the client.

2. The iris security authentication protocol based on inner product function encryption according to claim 1 is characterized in that: Step 1 includes the following specific steps: Step 1.1: The user uses the device to scan the iris to extract the original iris feature value X and mask M, and set two temporary keys K x and K m , where X, M, K x , K m ∈{0,1} 2028 ; Step 1.2: The user combines the original iris feature value X and mask M with two temporary keys K x and K m XOR encryption is performed, that is Step 1.3: The user sends the XOR-encrypted ciphertext S and T to the server for storage.

3. The iris security authentication protocol based on inner product function encryption according to claim 1 is characterized in that: Step 2 includes the following specific steps: Step 2.5: The key distribution center KGC generates a master private key msk1 consisting of random numbers with a length of l=2028=(s 1,1 ,s 1,2 ,…,s 1,l ) and msk2=(s 2,1 ,s 2,2 ,…,s 2,l ),in Step 2.6: The key distribution center KGC calculates the public key mpk1 = (h 1,1 ,h 1,2 ,…,h 1,l ) and mpk2=(h 2,1 ,h 2,2 ,…,h 2,l ),in Step 2.7: The key distribution center KGC sends the master private keys msk1 and msk2 and the public keys mpk1 and mpk2 to the client.

4. The iris security authentication protocol based on inner product function encryption according to claim 1 is characterized in that: Step 3 includes the following specific steps: Step 3.1: The server sends the encrypted user's iris mask T to the client, and the client decrypts it to obtain the iris mask Step 3.2: The client XORs the iris feature value X' to be identified to obtain the ciphertext where X'∈{0,1} 2028 ; Step 3.3: Client Calculation and x2=(x 2,1 ,x 2,2 ,…,x 2,l )=M·M'.

5. The iris security authentication protocol based on inner product function encryption according to claim 1 is characterized in that: Step 4 includes the following specific steps: Step 4.1: The server calculates two decryption vectors and y2=(y 2,1 ,y 2,2 ,…,y 2,l )=(1,1,…,1) and sent to the key distribution center KGC.

6. The iris security authentication protocol based on inner product function encryption according to claim 1 is characterized in that: Step 5 includes the following specific steps: Step 5.3: The server calculates the Hamming distance 7. The iris security authentication protocol based on inner product function encryption according to claim 1 is characterized in that: Step 6 includes the following specific steps: Step 6.1: The server judges based on the recognition parameter d2 and the Hamming distance NHD. If NHD<τ and d2>η, it proves that the two sets of iris data are taken from the same iris. τ and η are the thresholds of NHD and d2, respectively, which determine the accuracy of recognition and the security of the protocol. In the protocol, the two are fixed and the specific values ​​need to be set after testing the iris feature extraction algorithm used in advance; Step 6.2: The server sends the judgment result to the client.

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