WO2008122236A1

WO2008122236A1 - Method, device and system for protecting biometric feature data

Info

Publication number: WO2008122236A1
Application number: PCT/CN2008/070662
Authority: WO
Inventors: Quan Feng; Hongwei Liu; Fei Su; Jiwei Wei
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-04-05
Filing date: 2008-04-02
Publication date: 2008-10-16
Also published as: CN101282217A

Abstract

A method, a device and a system for protecting a biometric feature template are provided, which belong to the recognition field, wherein the method includes: encrypting a user biometric feature data by using a key, and generating the encrypted biometric feature data; binding the data of the user biometric characteristic with the key, and generating a biometric key corresponding to the encrypted biometric feature data. The present invention encrypts the biometric feature data by using a conventional key, binds the data of the user biometric characteristic with the conventional key, and generates the biometric key corresponding to the encrypted biometric feature data; thereby the security and the reliability of the biometric feature data protection could be improved, meanwhile, the security and the reliability of the biometric certification could be improved as well.

Description

Method, device and system for protecting biometric data

The present invention relates to the field of identification technologies, and in particular, to a method, device and application for protecting biometric data. Background of the invention

Biometric authentication is an effective method of identity authentication. This method usually relies on the biometric samples provided by the user on site and the biometric templates generated during the registration phase. If they match, the user identity is confirmed.

However, in addition to the reliability of the biometric authentication technology itself, the key factor affecting its large-scale application is security. Among several security-related issues, the protection of biometric templates is an extremely important issue. It can be said that it is biometric. The basis of security.

In the prior art, the biometric template can be protected by using a traditional encryption method. In this method, the security of the biometric template depends on the security of the encryption key. Generally, the key is encrypted by the user password. However, simple passwords are easy to guess, complex passwords are difficult to remember, and passwords are not non-repudiation, which is very disadvantageous in the case of using key signatures. Therefore, the method of protecting the biometric template by using the traditional encryption method still has a large security risk. Summary of the invention

Embodiments of the present invention provide a method, device, and application for protecting biometric data, by encrypting biometric data by using a traditional key, and binding the traditional key and the biometric data of the user to generate the encrypted biometric. The bio-key corresponding to the data achieves the purpose of improving the security and reliability of biometric data protection, and at the same time improves the security and reliability of biometric authentication.

The embodiment of the invention provides a method for protecting biometric data, including:

Encrypting user biometric data by using a key to generate encrypted biometric data;

Generating biometric data of the user according to the biometric data of the user;

Binding the key to the biometric data of the user to generate a biometric key corresponding to the encrypted biometric data.

The method for protecting biometric data provided by the embodiment of the invention includes:

Recovering the key from the biometric key using the user's biometric sample;

The encrypted biometric data is decrypted using the recovered key to obtain biometric data. The method for biometric authentication provided by the embodiment of the invention includes: Encrypting biometric data with a key to generate encrypted biometric data;

Binding the key to the biometric data to generate a biometric key;

Depositing the encrypted biometric data and the biometric key into the same biometric certificate;

Recovering the key from the biometric key using the user's biometric sample;

The encrypted biometric data is decrypted by using the recovered key to obtain biometric data; the biometric sample of the user is matched with the biometric data, and when the matching is correct, the user identity is confirmed.

The protection device for biometric data provided by the embodiment of the invention includes:

An encrypted biometric data generating unit, configured to encrypt user biometric data by using a key to generate encrypted biometric data;

a biometric key generating unit, configured to generate biometric data of the user according to the biometric data of the user, and bind the key to biometric data of the user to generate a biometric corresponding to the encrypted biometric data. key.

a biometric key processing unit for recovering a key from a biometric key using a biometric sample of the user; an encrypted biometric data processing unit for encrypting the biometric using the key pair recovered from the biometric key processing unit The feature data is decrypted to obtain biometric data.

The protection system for biometric data provided by the embodiment of the invention includes:

a registration unit, configured to encrypt user biometric data by using a key, generate encrypted biometric data, generate biometric data of the user according to the biometric data of the user, and generate the key with the user's biometric Binding the characteristic data to generate a biometric key corresponding to the encrypted biometric data; storing the generated encrypted biometric data and the biometric key;

And a decryption unit, configured to recover the key from the biometric key by using the biometric sample of the user; and decrypt the encrypted biometric data by using the recovered key to obtain biometric data.

The system for biometric authentication provided by the embodiment of the invention includes:

a registration unit, configured to encrypt user biometric data by using a key, generate encrypted biometric data, generate biometric data of the user according to the biometric data of the user, and generate the key with the user's biometric Binding the characteristic data to generate a biometric key corresponding to the encrypted biometric data; storing the generated encrypted biometric data and the biometric key; a decryption unit, configured to recover a key from the biometric key by using the biometric sample of the user; and decrypt the encrypted biometric data by using the recovered key to obtain biometric data;

The identification unit is configured to match the biometric sample of the user with the biometric data, and confirm the identity of the user when the matching is correct.

It can be seen from the technical solutions provided by the foregoing embodiments of the present invention that the embodiments of the present invention provide a method and a device for protecting biometric data by encrypting biometric data by using a traditional key, and using the traditional key and the user's biometric data. Binding together to generate the biometric key corresponding to the encrypted biometric data, thereby achieving the purpose of improving the security and reliability of the biometric data protection, and improving the security and reliability of the biometric authentication. BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic flowchart of a method for protecting biometric data according to an embodiment of the present invention;

2 is a schematic flowchart of a method for protecting biometric data according to still another embodiment of the present invention;

3 is a schematic flowchart of a method for biometric authentication according to an embodiment of the present invention;

4 is a schematic structural diagram of a biometric data protection apparatus according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a biometric data protection apparatus according to still another embodiment of the present invention; FIG.

6 is a schematic structural diagram of a biometric data protection system according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a system for biometric authentication according to an embodiment of the present invention. Mode for carrying out the invention

The method, device and system of the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

First, the method for protecting the biometric data according to the embodiment of the present invention is described. Specifically, the application of the biometric data protection method in the biometric template in the embodiment of the present invention is described in detail.

The method in the embodiment of the present invention is as shown in FIG. 1 , and specifically includes the following steps:

Encrypting the biometric data in the biometric template to generate the encrypted biometric data, and the biometric template storing the encrypted biometric data may be referred to as an encryption template;

Selecting a plurality of feature points from the biometric data, the feature points may be referred to as biometric data; binding the key KEY used in the encryption technology to the biometric data to obtain binding information; using the fuzzy vault method The interference information is added to the binding information, that is, the biometric data is hidden in a group of random interference data to generate a biometric key;

The generated biokey and encryption template are stored in the same biometric certificate.

The following takes the fingerprint in the biometric as an example to protect the biometric data in the embodiment of the present invention. The application in the feature template is illustrated. Here, the feature point (ie, biometric data) selected from the biometric data may be a fingerprint minutiae point, the biometric template is a fingerprint template, and the biometric key is a fingerprint key.

First, the cryptographic technology is used to encrypt the minutiae in the fingerprint template. The fingerprint template obtained by the encryption may be referred to as an ciphering template, and the ciphering template is stored in the biometric certificate, and the biometric certificate may be stored in the server. It can also be distributed to the user and saved by the user; the encryption technology refers to a key generated by the user password or the encryption system, the specific process of generating the key KEY, and the specific process of encrypting the fingerprint template by using the key. There are mature solutions in the technology, so I will not repeat them here.

Then, the key KEY and the fingerprint minutiae used in the above encryption process are bound, the minutiae point refers to the tip point or the bifurcation point in the fingerprint, and the tip point refers to the end point of a stripe line, bifurcation Point refers to a point where a stripe line branches into two branches. The tip or minutiae point can be represented by a triplet (χ, γ, θ), where ^ is the plane coordinate of the location of the minutiae point, and 0 is the direction of the minutiae point, ie the direction of the associated ridge. In the specific binding process, the plane coordinates of the minutiae point can be used for binding, or the triad coordinates can be used for binding. The following is only a plane coordinate as an example to illustrate the specific binding process.

In the specific implementation process of the embodiment of the present invention, the key KEY and the fingerprint minutiae point may be bound by using a multivariate linear function. For example, if the length of the encryption key KEY is 128 bits, N (for example, N=9) real points having the same security effect as the 128-bit encryption key KEY can be selected as the condition for recovering the key. In this way, a multivariate linear function of 9 variables can be used:

Fiu) = a ^T u mod(_p ) =

Mod( p ) ( 1 ) where fl = [£/ ₀ t/i ... a ₈ ^T ] , « = [wo ... M ₈ ].

The key KEY is divided into 8 segments that do not overlap each other, respectively. . . , ^, 16 bits per segment, let αο ^, α si, ... , α _Ί = . Combine "^~« ₈ into a 128-bit number string KEYC aoai...^, and calculate the CRC-16 value C of the string KEYC, which is a 16-bit check value, let a ₈ = :. Mod ( ^ means to modulate the multivariate function value, p is the closest to 2 ¹⁶ -1, but is greater than one of its prime numbers, which is 65537.

Use F to represent the set of detail point plane coordinates in the fingerprint template, ie

(x yi), . . . , ( Ν-Ι,7Ν-Ι)} . where N is the total number of template minutiae points. For the convenience of later calculation, each detail point plane coordinate c and y can be mapped to [0, 255], respectively, and then they are connected in series to form a data binding unit w, which is a 16-bit data. This will give you a set of M = { _W o, _Wl , «7!^ }. For each w, =0—Nl, as a seed of a 16-bit random number generator, sequentially generate 8 random numbers, r ₁ , so that for each min. w, a vector ": uimi" is obtained. = [ u _i0 u _iX ... «; ₈ ] = [mi m ... r«]. will be Substituting into the above formula (1), calculating the corresponding

Thus, the set G of fingerprint keys consists of M and the linear function values corresponding to the elements: G = {( moJ[ ₀ (m ₀ )), (mij[ui(mi))) (OT _N-1 , X« _N-1 (OT _N-1 ))) };

In order to further improve the security of the fingerprint key, the fuzzy vault method can be used to protect the fingerprint key, that is, an interference set C can be constructed, and the role of C is to protect the security of the fingerprint key. It is composed of M point pairs. A set of constituents: C = {(cuc^ dA), ..., (c _M-1 , c/ _M-1 )}, where _C and 4·, =0—Ml are random numbers. The distance from w / must be greater than a certain threshold, and 4 ≠ _ / (c).

Add all the elements of the above set G and set C to a list VL and mix them thoroughly; if (v, w) is used to uniformly represent one element in G or C, then VL can be expressed as: VL = {( v ₀ ,w ₀ ), {(vi,wi), ..., (VM ₊ NI,WM ₊ NI)} . VL is a new, protected fingerprint key obtained by the Fuzzy vault method, which is stored Go to the same biometric certificate that holds the encryption template above.

A further embodiment of the present invention provides a method for protecting biometric data, which is specifically described in the application of the biometric data protection method according to the embodiment of the present invention.

As shown in FIG. 2, the method in the embodiment of the present invention specifically includes the following steps:

Binding information is obtained by binding the biometric sample of the user and the biometric key;

Recovering the key KEY from the binding information;

Decrypting the encryption template by using the key KEY to obtain a biometric template;

The application of the biometric data protection method according to another embodiment of the present invention in the biometric template will be described in detail below by taking the fingerprint in the biometric as an example.

As shown in Figure 2, when the user needs to use the key KEY, the KEY can be recovered from the binding information. At this time, the user provides a fingerprint sample on the spot. After the system aligns and preprocesses the fingerprint sample and the biokey, the query detail point set Q, Q={(x _g o, y _g o), is extracted from the fingerprint sample. (x _g y _g i), . . . , (3⁄4Ν*-Ι,3⁄4Ν*-Ι)} , Ν* is the total number of minutiae points in Q, usually Ν*≠Ν. The plane coordinates JC and y of the minutiae points are mapped to [0, 255] as well. Take ^,..., ^^^ from VL. They are all 16-bit numbers, which are split into two 8-bit numbers. As a plane coordinate, you can get a set.

o Use the elements in Q to locate the elements in Rc. If the distance between a certain detail point A in the set Q and a certain detail point B in the set Rc is less than a threshold, then A and B can be considered as a pair of matching points. , you can add the corresponding B to the matching point set Ro, namely:

For all 0< N* ((x _qi ,y _q d≡ Q) and 0</-<V+M ((x _vj ,y _vj )≡ Rc)

If O((x _qi ,y _qi ), ix _j ,y _v j))≤T then iy^wj)≡ RQ Where r is a threshold.

If it is a real user, using Q can produce a smaller R _e . Suppose that R _e has K points, usually K ≤ N * « V + M, which can greatly narrow the search range when recovering the key. In order to recover the key KEY, K should have at least 9 points. Even for real users, false points are mixed into R _G , because usually the live fingerprint and the template fingerprint are only partially overlapping, and there is noise, so the points in Q and the points in set F only partially match. Those mismatched points in Q may still find the paired points from the interference set C, and these points do not help to reconstruct the key. Use all possible combinations of 9 points in Ro to recover the KEY. For each 16-bit random number generator using the same parameters as the key binding phase, ν,· is used as a seed to generate 8 random numbers, m, r _i2 , ..., r _{8 in} sequence. Thus for each V ERG, you get a vector ^:

u _vi = [ u _i() Ui\ ... u _t [ = [vi r ... r/ ₈ ]

And its corresponding multivariate linear function value

Wj = "w) = au _vi mod(_p ) = ad Ui+ nn +... +£3⁄47 7+£3⁄48"8 mod(p ) (2) For a particular combination {(νο,τνο), {(vi, Wi), (v ₈ , w ₈ )}, you can get a linear system of equations: wo = ado3⁄4o+adi3⁄4i+ -.. +ad73⁄47+«d83⁄48 mod(p )

Wi = adoMi,o+adiMi,i+ ... +adiowi,7+adiiwi, ₈ mod( ) w ₈ = ado3⁄4o+a _d i3⁄4i+ ... +ad ₇ M ₈ , ₇ +a _d8 M ₈ , ₈ mod( Jf ) Let C/ ... w ₈ ] ^T , fld = [OdO Odl

The group can be simplified to:

τ

w = Ua^ mod(p) (3)

Since _V1 , ..., _V13 as seeds are not the same, in general, each row of the random matrix is irrelevant, and the determinant |U|≠ 0, which can be guaranteed to be reversible, and thus solved from (3) Fl ^T :

If 3⁄4, w ₀ ), ... , (v ₈ , w ₈ ) is an element in G, then there is fl _d ^T = fl ^T . It can be verified by CRC test whether fl _d ^T is true. Connect a _d o, a _d i, _{d7 in} series to form a 128-bit string KEYC*, and calculate its CRC-16 value. If the value is exactly equal to a _d8 , then (v., w ₀ ), ... , ( v ₈ , w ₈ ) has a very high probability of belonging to G, and has a very high probability equal to _fl ^T . The CRC is just a method of error detection. It does not reveal any information about the key KEY itself. Without the actual live sample condition, the attacker cannot directly use the CRC check to unlock the Finger vault.

If fl passes the CRC test, it will be a _d . , a _dl , ... , a _{d7 are} connected in series to form a number string KEY*, KEY*=KEY, This restores the key KEY.

Finally, the encryption template is decrypted by using the key KEY to obtain a fingerprint template. The fingerprint template is matched with the fingerprint sample provided by the user on the site to complete the authentication process.

The above method is described by taking a key generated by a symmetric encryption algorithm as an example, that is, the encryption key and the decryption key use the same key, and the embodiment of the present invention is also applicable to the non-pairing encryption algorithm, gP, When registering, the biometric data in the biometric template is encrypted by using the encryption key, and then the decryption key is matched with the selected fingerprint detail point. When the authentication is performed, the decryption key recovered from the biometric key template is used. The fingerprint details are restored, and the other processing is similar to the method described above, and will not be described here.

The embodiment of the present invention can also bind the user's secret to the key. For example, if the user's secret is S, it can be the user's password, user name or other things, and some combination of these things, using a function. It is transformed into a string of numbers SV equal to the key Key to be protected, BP : SV = /(S).

When the key is bound, it is assumed that the Key is 128 bits. As in the previous method, the SV is divided into 8 segments that do not overlap each other, svo, svi, ..., sv ₇ , each segment 16 bits (128/16 = 8), In the formula (1), let ao = s ₀ ® sv ₀ , ai = si @ sv ... , αη = ten ^ 7. We combine αο~α ₈ into a 128-bit number string KEYC aoai ...^, and calculate its CRC-16 value C, so that a ₈ =:. Thus the coefficients of equation (1) are determined, and other calculations can be performed as described above.

When the key is reconstructed, α is obtained as described above. , αχ, ... , α _Ί , the user-supplied S can still be formed. , SV . . . , sv ₇ , Bay 1^ ₀ = " ₀ ten ^o, 1 = "1 ten ^i,... , s ₇ = a ₇ @ sv ₇ , Key= s ₀ si s ₂ S3 s ₄ s ₅ s ₆ s

The present invention also provides a method for performing biometric authentication by using the above-mentioned biometric data protection method. As shown in FIG. 3, the method includes:

When registering, the biometric data in the biometric template is encrypted by using an encryption technology to generate encrypted biometric data, and the biometric template may be referred to as an encryption template at this time; the key and the biometric in the encryption technology are The biometric data selected in the template is bound to generate a biometric key; the biometric key and the encrypted template are stored in the same biometric certificate;

At the time of authentication, the user's biometric sample is used to recover the biometric data bound to the key from the biometric key, and the key is recovered; and the encrypted template is decrypted by the recovered key to obtain the biological Characteristic data

The biometric samples of the user are matched with the biometric data. When the matching is correct, the user identity is confirmed. Since the specific matching process has a mature solution, it will not be described here.

The protection device for biometric data according to the embodiment of the present invention will be described in detail below.

As shown in FIG. 4, the protection device for the biometric template according to the embodiment of the present invention includes: The encrypted biometric data generating unit is configured to encrypt the biometric data in the biometric template by using an encryption technology to generate the encrypted biometric data, and the biometric template storing the encrypted biometric data may be referred to as encryption. The algorithm used by the encryption technology may be a symmetric encryption algorithm or an asymmetric encryption algorithm;

a biometric key generating unit configured to bind a key in the encryption technology to the biometric data of the user by using a multivariate linear function to generate a biometric key; the biometric data may be biometric data from the biometric template Multiple feature points selected in the image, for example, fingerprint detail points.

The device also includes:

a biometric certificate storage unit, configured to store an encryption template obtained from the encrypted biometric data generating unit and a biometric key obtained from the biometric key generating unit, where the biometric credential storage unit is located in the server or at the user equipment .

The biometric key generating unit may specifically include:

The binding module is configured to bind the key to the biometric data by using a multivariate linear function to generate binding information, where the binding process has been described in detail in the method, and is not described herein again;

The interference module is configured to protect the binding information by using a Fuzzy vault method, that is, adding interference information to the binding information to generate a biometric key.

The protection device for biometric data according to still another embodiment of the present invention will be described in detail below.

As shown in FIG. 5, the protection device of the biometric data specifically includes:

a bio-key processing unit for recovering a key from a bio-key by solving a multivariate linear function using a biometric sample of the user;

The encrypted biometric data processing unit is configured to decrypt the encrypted biometric data by using the key recovered by the biometric key processing unit to obtain biometric data.

The biometric key processing unit may specifically include:

The interference cancellation module is configured to: when the interference information is added to the biometric data with the key bound by using the Fuzzy vault method, the interference cancellation module is configured to recover the binding information from the biometric key;

Unbinding module: recovers the key from the binding information by solving the multivariate linear function.

The embodiment of the present invention further provides a protection system for the biometric data, as shown in FIG. 6 , which specifically includes: a registration unit, configured to encrypt biometric data in a biometric template by using an encryption technology to obtain an encrypted biometric The feature data, the biometric template storing the encrypted biometric data may be referred to as an encryption template; the algorithm used by the encryption technology may be a symmetric encryption algorithm or an asymmetric encryption algorithm; Binding the key in the encryption technology to the biometric data of the user by using a multivariate linear function to generate a biometric key; storing the obtained encryption template and the biometric key;

The decryption unit recovers the key from the biometric key by solving the multivariate linear function by using the biometric sample of the user; and then decrypting the encrypted template by using the key to obtain biometric data in the biometric template.

The embodiment of the present invention further provides a system for biometric authentication. As shown in FIG. 7, the biometric authentication system may include:

a registration unit, configured to encrypt the biometric template by using an encryption technology to generate an encryption template; the algorithm used by the encryption technology may be a symmetric encryption algorithm or an asymmetric encryption algorithm; and the registration unit uses a multivariate linear function to encrypt The key in the technology is bound to the biometric data of the user to generate a biometric key; the obtained encryption template and the biometric key are stored;

The identity unit is responsible for matching the biometric sample of the user with the biometric data in the biometric template, and confirming the identity of the user when the matching is correct.

The specific implementation process of the device according to the embodiment of the present invention has not been specifically described herein because it has been described in detail in the foregoing method.

In summary, the embodiment of the present invention encrypts a fingerprint template by using a key, and then binds the key and the fingerprint detail point by using a multivariate linear function. In the authentication, only the user needs to provide the on-site sample feature. The key is restored to decrypt the biological template for more precise comparison, thereby improving the security and reliability of the fingerprint template protection.

Herein, the embodiment of the present invention only uses the application of the biometric data protection method on the biometric template as an example, and specifically uses the fingerprint in the biometric as an example to illustrate the protection method and application of the fingerprint template. However, those skilled in the art should be aware that the embodiment of the present invention is also applicable to the biometric template protection to other biometrics other than fingerprints, such as iris, palm print, voice, etc., and the implementation process is similar to the method described above; In addition, the embodiment of the present invention can be applied to all scenarios that need to protect the biometric data in addition to the protection of the biometric template. In this case, only a slight change can be implemented in the embodiment of the present invention. I won't go into details.

The above is only a preferred embodiment of the present invention, but the scope of protection of the embodiments of the present invention is not limited thereto, and any person skilled in the art is within the technical scope disclosed by the embodiments of the present invention. Variations or substitutions that are conceivable are intended to be included within the scope of the embodiments of the invention. Therefore, the scope of protection of the embodiments of the present invention should be determined by the scope of the claims.

Claims

Rights request

A method for protecting biometric data, comprising:

2. The method of claim 1 wherein

The step of generating biometric data of the user according to the biometric data of the user includes: selecting a plurality of feature points from the biometric data of the user to obtain biometric data of the user; and the key and biometric data The steps of binding and generating a biometric key include:

The biometric data is bound to the key using a multivariate linear function to generate a biometric key.

The method according to claim 2, wherein the step of binding the biometric data with a key by using a multivariate linear function to generate a biometric key comprises:

Binding the biometric data to the key by using a multivariate linear function to generate binding information; adding interference information to the binding information to generate a biometric key.

The method according to any one of claims 1 to 3, wherein the method further comprises: storing the generated encrypted biometric data and the biometric key in the same biometric certificate.

5. A method for protecting biometric data, comprising:

Recovering the key from the biometric key using the user's biometric sample;

The encrypted biometric data is decrypted using the recovered key to obtain biometric data.

The method according to claim 5, wherein the step of recovering the key from the biometric key by using the biometric sample of the user comprises:

Selecting a plurality of feature points from the biometric sample;

According to the feature points in the biometric sample, the biometric key is decrypted by using a multivariate linear function to obtain a key for encrypting the biometric data.

The method according to claim 5, wherein the step of recovering the key from the biometric key using the biometric sample of the user comprises:

Recover binding information from the biokey;

The key is recovered from the binding information using a multivariate linear function.

8. A method of biometric authentication, comprising: Encrypting biometric data with a key to generate encrypted biometric data;

Binding the key to the biometric data to generate a biometric key;

Recovering the key from the biometric key using the user's biometric sample;

9. A device for protecting biometric data, comprising:

The device according to claim 9, wherein the device further comprises:

a biometric certificate storage unit, configured to store the obtained encrypted biometric data and the biometric key.

The device according to claim 9 or 10, wherein the biometric key generating unit specifically comprises:

a binding module, configured to bind the key to the biometric data by using a multivariate linear function to generate binding information;

The interference module is configured to add interference information to the binding information to generate a biometric key.

12. A device for protecting biometric data, comprising:

The device according to claim 12, wherein the bio-key processing unit comprises: a de-interference module, recovering binding information from the bio-key;

The unbinding module recovers the key from the binding information by using a multivariate linear function.

14. A system for protecting biometric data, comprising:

a registration unit, configured to encrypt user biometric data by using a key to generate encrypted biometric data, Generating the biometric data of the user according to the user biometric data, and binding the key with the biometric data of the user to generate a biometric key corresponding to the encrypted biometric data; The encrypted biometric data and the biometric key are stored;

15. A biometric authentication system, comprising:

a decryption unit, configured to recover a key from the biometric key by using the biometric sample of the user; and decrypt the encrypted biometric data by using the recovered key to obtain biometric data;