GENERATION OF RANDOMIZED MESSAGES FOR CRYPTOGRAPHIC HASH FUNCTIONS

• US 20140298038A1
• Filed: 11/20/2013
• Published: 10/02/2014
• Est. Priority Date: 03/26/2013
• Status: Active Grant

• Current Assignee: TATA Consultancy Services Limited (Tata Sons Pvt Ltd.)
• Original Assignee: TATA Consultancy Services Limited (Tata Sons Pvt Ltd.)
• Inventors: Gauravaram, Praveen
• Granted Patent: US 9,444,619 B2
• Time in Patent Office: Days
• US Class Current: 713/189
• CPC Class Codes: H04L 9/0643 Hash functions, e.g. MD5, SHA, HMAC or f9 MAC
• CPC Class Codes: H04L 9/0869 involving random numbers or seeds

Abstract

Method(s) and system(s) for generation of randomized messages for cryptographic hash functions are described herein. The method includes obtaining a random value based on a randomization criterion to randomize a message. Further, a last data block of the message is populated with a randomization parameter to obtain a randomized message. The randomization parameter populated in the last block is computed using the random value.

Claims

1. A randomized message generation system comprising:

;

processor(s);

a primary randomization module coupled to the processors, the primary randomization module obtains a random value based on a randomization criterion to randomize a message; and

a secondary randomization module coupled to the processors, the secondary randomization module populates a last data block of the message with a randomization parameter to obtain a randomized message for use in a cryptographic hash function, wherein the randomization parameter is computed using the random value.

2. The randomized message generation system as claimed in claim 1, wherein the secondary randomization module further determines:

space occupied by padding bits in the last data block;

available space in the last data block based on the space occupied by the padding bits and message bits in the last data block to compute the randomization parameter.

3. The randomized message generation system as claimed in claim 1, wherein the primary randomization module further:

determines a block length of a compression function, wherein the compression function is a component of the cryptographic hash function used for hashing the randomized message;

divides the message into a predetermined number of data blocks based on the block length of the compression function; and

concatenates the random value to itself a predetermined number of times, based on the block length of the compression function.

4. The randomized message generation system as claimed in claim 3, wherein the secondary randomization module randomizes each of the predetermined number of data blocks using the concatenated random value, wherein the concatenated random value is mixed with a data block using a mixing function.

5. The randomized message generation system as claimed in claim 1, wherein the secondary randomization module further:

ascertains whether a current last data block of the message can accommodate the randomization parameter; and

appends an additional data block at the end of the message, when the current last data block cannot accommodate the randomization parameter.

6. The randomized message generation system as claimed in claim 1, wherein the secondary randomization module further:

appends a data block at the beginning of the message; and

populates the data block with a random factor, wherein the random factor is based on the random value and a block length of a compression function.

7. A method for generating randomized messages for cryptographic hash functions comprising:

obtaining a random value based on a randomization criterion to randomize a message; and

populating a last data block of the message with a randomization parameter to obtain a randomized message, wherein the randomization parameter is computed using the random value.

8. The method for generating randomized messages as claimed in claim 7, wherein the last data block further includes padding bits.

9. The method for generating randomized messages as claimed in claim 7, wherein the method further comprises:

ascertaining whether a current last data block of the message can accommodate the randomization parameter; and

appending an additional data block at the end of the message, when the current last data block can not accommodate the randomization parameter.

10. The method for generating randomized messages as claimed in claim 7, wherein the method further comprises:

dividing the message into a predetermined number of data blocks based on the block length of a compression function;

concatenating the random value to itself a predetermined number of times, based on the block length; and

randomizing each of the predetermined number of data blocks using the concatenated random value.

11. The method for generating randomized messages as claimed in claim 7, wherein the method further comprises:

appending a data block at the beginning of the message; and

populating the data block with a random factor, wherein the random factor is based on the random value and a block length of a compression function.

12. The method for generating randomized messages as claimed in claim 7, wherein the method further comprises:

determining space occupied by padding bits in the last data block; and

determining available space in the last data block based on the space occupied by the padding bits and message bits in the last data block to compute the randomization parameter.

13. A non-transitory computer-readable medium having embodied thereon a computer program for executing a method for authenticating a user, the method comprising:

obtaining a random value based on a randomization criterion to randomize a message; and

populating a last data block of the message with a randomization parameter to obtain a randomized message, wherein the randomization parameter is computed using the random value.

14. The non-transitory computer-readable medium as claimed in claim 13, wherein the method further comprises:

ascertaining whether a current last data block of the message can accommodate the randomization parameter; and

appending an additional data block at the end of the message, when the current last data block cannot accommodate the randomization parameter.

15. The non-transitory computer-readable medium as claimed in claim 13, wherein the method further comprises:

dividing the message into a predetermined number of data blocks based on the block length of a compression function;

concatenating the random value to itself a predetermined number of times, based on the block length; and

randomizing each of the predetermined number of data blocks using the concatenated random value.

16. The non-transitory computer-readable medium as claimed in claim 13, wherein the method further comprises:

appending a data block at the beginning of the message; and

populating the data block with a random factor, wherein the random factor is based on the random value and a block length of a compression function.