Protecting passwords and biometrics against back-end security breaches

• US 9,887,989 B2
• Filed: 04/22/2016
• Issued: 02/06/2018
• Est. Priority Date: 06/23/2012
• Status: Active Grant

• Current Assignee: Pomian & Corella LLC
• Original Assignee: Pomian & Corella LLC
• Inventors: Corella, Francisco, Lewison, Karen Pomian
• Primary Examiner(s): King, John B
• Application Number:
  US15/136,834
• Publication Number:
  US 20160269393A1
• Time in Patent Office: 655 Days
• CPC Class Codes: G06F 21/32 using biometric data, e.g. fingerprints, iris scans or voiceprints
• CPC Class Codes: G06F 21/33 using certificates
• CPC Class Codes: G06F 21/41 where a single sign-on provides access to a plurality of computers
• CPC Class Codes: G06F 21/45 Structures or tools for the administration of authentication
• CPC Class Codes: H04L 63/045 wherein the sending and receiving network entities apply hybrid encryption, i.e. combination of symmetric and asymmetric encryption cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• CPC Class Codes: H04L 63/0807 using tickets, e.g. Kerberos cryptographic mechanisms or cryptographic arrangements for entity authentication using tickets or tokens H04L9/3213
• CPC Class Codes: H04L 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226
• CPC Class Codes: H04L 63/0861 using biometrical features, e.g. fingerprint, retina-scan cryptographic mechanisms or cryptographic arrangements for entity authentication using biological data H04L9/3231
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics
• CPC Class Codes: H04L 9/3213 using tickets or tokens, e.g. Kerberos network architectures or network communication protocols for entities authentication using tickets in a packet data network H04L63/0807
• CPC Class Codes: H04L 9/3226 using a predetermined code, e.g. password, passphrase or PIN network architectures or network communication protocols for supporting authentication of entities using passwords in a packet data network H04L63/083
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

A method and system are provided for authenticating a user to an application back-end using a key pair and one or more bearer tokens such as a password, a biometric code, or a biometric key, while protecting the bearer tokens against back-end security breaches. In one embodiment, an application front-end authenticates the user by sending the bearer tokens and a public key to the application back-end, and demonstrating knowledge of a private key. The application back-end compares an authentication-phase tag derived from a joint hash of the public key and the bearer tokens against a registration-phase tag stored in a device record within a back-end database. The public key is not stored in the database, thereby depriving an adversary who breaches back-end security of information needed to test guesses of the bearer tokens.

Claims

1. A multifactor authentication method for authenticating a user of an application while mitigating back-end security breaches, the application comprising an application front-end running on a computing device and an application back-end running on a server, the server being part of a back-end subsystem, the back-end subsystem comprising a back-end storage medium, the method comprising:

during a registration phase, the application front-end sending to the application back-end one or more registration-phase bearer tokens;

during the registration phase, the application back-end computing a registration-phase tag derived from a registration-phase joint hash of a public key and the one or more registration-phase bearer tokens, the public key being a component of a key pair pertaining to an asymmetric cryptosystem, the public key being treated by the application as a secret shared between the application front-end and the application back-end, wherein the public key is never communicated by the application front-end or the application back-end to any third party;

during the registration phase, the application back-end storing the registration-phase tag in the back-end storage medium;

during the registration phase, the application back-end deleting the public key and the one or more registration-phase bearer tokens from the back-end subsystem after computing the registration-phase tag;

during an authentication phase, the application front-end sending to the application back-end the public key and one or more authentication-phase bearer tokens;

during the authentication phase, the application front-end proving to the application back-end knowledge of a private key associated with the public key, the private key being a component of the key pair;

during the authentication phase, the application back-end computing an authentication-phase tag derived from an authentication-phase joint hash of the public key and the one or more authentication-phase bearer tokens;

during the authentication phase, the application back-end deleting the public key and the one or more authentication-phase bearer tokens from the back-end subsystem after computing the authentication-phase tag; and

during the authentication phase, the application back-end verifying that the authentication-phase tag is equal to the registration-phase tag.

2. The method of claim 1, wherein the public key and the associated private key pertain to an asymmetric digital signature cryptosystem and the application front-end proves knowledge of the private key to the application back-end by using the private key to compute a signature, the signature being verified by the application back-end.

3. The method of claim 1, wherein the public key and the associated private key pertain to an asymmetric key-exchange cryptosystem and the application front-end proves knowledge of the private key to the application back-end by using the private key to perform a key exchange with the application back-end.

4. The method of claim 1, wherein the public key and the associated private key pertain to an asymmetric encryption cryptosystem and the application front-end proves knowledge of the private key to the application back-end by using the private key to decrypt a nonce encrypted by the application back-end.

5. The method of claim 1, wherein one of the one or more registration-phase bearer tokens is a registration-phase password, and one of the one or more authentication-phase bearer tokens is an authentication-phase password.

6. The method of claim 1, wherein the application front-end is part of a front-end subsystem that comprises a front-end storage medium, and one of the one or more authentication-phase bearer tokens sent by the application front-end to the application back-end is derived from a joint hash of a salt stored in the storage medium and an authentication-phase password.

7. The method of claim 1, wherein one of the one or more authentication-phase bearer tokens is an authentication-phase biometric key.

8. The method of claim 1, wherein the application front-end is part of a front-end subsystem that comprises a front-end storage medium, and one of the one or more authentication-phase bearer tokens sent by the application front-end to the application back-end is derived from a joint hash of a salt stored in the front-end storage medium and an authentication-phase biometric key.

9. The method of claim 1, wherein one of the one or more authentication-phase bearer tokens is an authentication-phase biometric code and computing the authentication-phase tag comprises computing an authentication phase biometric key derived from the authentication-phase biometric code.

10. A system for authenticating a user while mitigating back-end security breaches, comprising:

a computing device;

a network;

a server connected to the computing device by the network, the server being part of a back-end subsystem, the back-end subsystem comprising a back-end storage; and

an application comprising an application front-end running on the computing device and an application back-end running on the server,

wherein the application front-end and the application back-end jointly perform a method of authenticating a user of the application, the method comprising;

during a registration phase, the application front-end sending to the application back-end one or more registration-phase bearer tokens;

during the registration phase, the application back-end computing a registration-phase tag derived from a registration-phase joint hash of a public key and the one or more registration-phase bearer tokens, the public key being a component of a key pair pertaining to an asymmetric cryptosystem, the public key being treated by the application as a secret shared between the application front-end and the application back-end, wherein the public key is never communicated by the application front-end or the application back-end to any third party;

during the registration phase, the application back-end storing the registration-phase tag in the back-end storage medium;

during the registration phase, the application back-end deleting the public key and the one or more registration-phase bearer tokens from the back-end subsystem after computing the registration-phase tag;

during an authentication phase, the application front-end sending to the application back-end the public key and one or more authentication-phase bearer tokens;

during the authentication phase, the application front-end proving to the application back-end knowledge of a private key associated with the public key, the private key being a component of the key pair;

during the authentication phase, the application back-end computing an authentication-phase tag derived from an authentication-phase joint hash of the public key and the one or more authentication-phase bearer tokens;

during the authentication phase, the application back-end deleting the public key and the one or more authentication-phase bearer tokens from the back-end subsystem after computing the authentication-phase tag; and

during the authentication phase, the application back-end verifying that the authentication-phase tag is equal to the registration-phase tag.

11. The system of claim 10, wherein one of the one or more registration-phase bearer tokens is a registration-phase password, and one of the one or more authentication-phase bearer tokens is an authentication-phase password.

12. The system of claim 10, wherein the application front-end is part of a front-end subsystem that comprises a front-end storage medium, and one of the one or more authentication-phase bearer tokens sent by the application front-end to the application back-end is derived from a joint hash of a salt stored in the storage medium and an authentication-phase password.

13. The system of claim 10, wherein one of the one or more authentication-phase bearer tokens is an authentication-phase biometric key.

14. The system of claim 13, wherein the authentication-phase biometric key is a randomized biometric key derived from an authentication-phase biometric code and biometric helper data.

15. The system of claim 10, wherein the application front-end is part of a front-end subsystem that comprises a front-end storage medium, and one of the one or more authentication-phase bearer tokens sent by the application front-end to the application back-end is derived from a joint hash of a salt stored in the front-end storage medium and an authentication-phase biometric key.

16. The system of claim 15, wherein the authentication-phase biometric key is a randomized biometric key derived from an authentication-phase biometric code and biometric helper data.

17. The system of claim 10, wherein one of the one or more authentication-phase bearer tokens is an authentication-phase biometric code and computing the authentication-phase tag comprises computing an authentication phase biometric key derived from the authentication-phase biometric code.

18. The system of claim 17, wherein the authentication-phase biometric key is a randomized biometric key that is further derived from biometric helper data.