Token authentication system and method

• US 20070050635A1
• Filed: 02/23/2005
• Published: 03/01/2007
• Est. Priority Date: 02/23/2004
• Status: Active Grant

• Current Assignee: Gen Digital Inc.
• Original Assignee: Symantec Corporation (NortonLifeLock Inc.)
• Inventors: Popp, Nicolas
• Granted Patent: US 8,639,628 B2
• Time in Patent Office: Days
• US Class Current: 713/185
• CPC Class Codes: H04L 63/0838 using one-time-passwords
• CPC Class Codes: H04L 63/0853 using an additional device, e.g. smartcard, SIM or a different communication terminal cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234
• CPC Class Codes: H04L 9/0863 involving passwords or one-time passwords network architectures or network communication protocols for using one-time keys in a packet data network H04L63/067
• 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 9/3228 One-time or temporary data, i.e. information which is sent for every authentication or authorization, e.g. one-time-password, one-time-token or one-time-key
• CPC Class Codes: H04L 9/3234 involving additional secure or trusted devices, e.g. TPM, smartcard, USB or software token network architectures or network communication protocols for supporting authentication of entities using an additional device in a packet data network H04L63/0853
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC

Abstract

A method for calculating a One Time Password. A secret is concatenated with a count, where the secret is uniquely assigned to a token. The secret can be a private key or a shared secret symmetric key. The count is a number that increases monotonically at the token with the number of one-time Passwords generated at the token. The count is also tracked at an authentication server, where it increases monotonically with each calculation of a one-time Password at the authentication server. An OTP can be calculated by hashing a concatenated secret and count. The result can be truncated.

Claims

1. A method for calculating a One Time Password, comprising:

concatenating a secret with a count, where the secret is uniquely assigned to a token and is shared between the token and an authentication server, and the count is a number that increases monotonically at the token with the number of One Time Passwords generated at the token and increases monotonically at the authentication server with each calculation at the authentication server of a One Time Password;

calculating a hash based upon the concatenated secret and count; and

truncating the result of the hash to obtain a One Time Password.

2. A method for authenticating a request for access to a resource, comprising:

receiving at an authentication server a request for authentication that includes a serial number that is uniquely associated with a token, a personal identification number associated with a user and a One Time Password generated at a token, wherein the One Time Password is based upon the value of a count at the token and a secret shared between the token and the authentication server;

retrieving at the authentication server the value of a count that corresponds to the token based upon the serial number;

retrieving at the authentication server the secret that corresponds to the token based upon the serial number;

calculating at the authentication server the value of a One Time Password based upon retrieved values of the count and the secret corresponding to the token;

comparing the calculated One Time Password with the received One Time Password; and

if the calculated One Time Password corresponds to the received One Time Password, the request is determined to be authenticated;

if the calculated One Time Password does not correspond to the received One Time Password, then incrementing the value of the count at the authentication server and recalculating the One Time Password based upon the incremented count and the secret, and comparing the recalculated One Time Password with the received One Time Password;

if the recalculated One Time Password does not correspond to the received One Time Password, then repeating to increment the count and to recalculate the One Time Password until the recalculated One Time Password corresponds to the received One Time Password.

3. The method of claim 2, wherein the hash function is SHA-1.

4. The method of claim 2, wherein the secret is a symmetric cryptographic key.

5. The method of claim 2, wherein incrementing the count and recalculating the One Time Password is repeated a predetermined number of times, and if the recalculated One Time Password does not correspond to the received One Time Password by the end of the predetermined number of times, the request is determined to be not authenticated.

6. A method for authenticating a request for access to a resource, comprising:

receiving at an authentication server a request for authentication that includes a username that is uniquely associated with a user, a personal identification number associated with a user and a One Time Password generated at a token, wherein the One Time Password is based upon the value of a count at the token and a secret shared between the token and the authentication server;

retrieving at the authentication server the value of a count that corresponds to the token based upon the username;

retrieving at the authentication server the secret that corresponds to the token based upon the username;

calculating at the authentication server the value of a One Time Password based upon retrieved values of the count and the secret corresponding to the token;

comparing the calculated One Time Password with the received One Time Password; and

if the calculated One Time Password corresponds to the received One Time Password, the request is determined to be authenticated;

if the calculated One Time Password does not correspond to the received One Time Password, then incrementing the value of the count at the authentication server and recalculating the One Time Password based upon the incremented count and the secret, and comparing the recalculated One Time Password with the received One Time Password;

if the recalculated One Time Password does not correspond to the received One Time Password, then repeating to increment the count and to recalculate the One Time Password until the recalculated One Time Password corresponds to the received One Time Password.

7. The method of claim 6, wherein the hash function is SHA-1.

8. The method of claim 6, wherein the secret is a symmetric cryptographic key.

9. The method of claim 6, wherein incrementing the count and recalculating the One Time Password is repeated a predetermined number of times, and if the recalculated One Time Password does not correspond to the received One Time Password by the end of the predetermined number of times, the request is determined to be not authenticated.