Multiplicative blinding for cryptographic operations

Patent metadata

Field	Value
Publication number	US-10594471-B2
Application number	US-201615073225-A
Country	US
Kind code	B2
Filing date	Mar 17, 2016
Priority date	Mar 20, 2015
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

A value corresponding to an input for a cryptographic operation may be received. The value may blinded by multiplying the value based on an exponentiation of a random number raised to an exponent value that is associated with a public key. A cryptographic operation may be performed based on the blinded value.

First claim

What is claimed is:

1. A method comprising:
receiving a value corresponding to an input for a cryptographic operation;
blinding, by a processor of an integrated circuit, the value by multiplying the value based on an exponentiation of a random number raised to an exponent value that is associated with a public key;
receiving a second exponent value from a private key that corresponds to the public key;
decrementing the second exponent value from the private key to generate a decremented private key exponent value; and
performing, by the processor of the integrated circuit, the cryptographic operation based on the blinded value and the decremented private key exponent value, wherein the cryptographic operation corresponds to an encryption operation or a decryption operation.

2. The method of claim 1 , wherein the public key comprises the exponent value and a modulus value.

3. The method of claim 2 , wherein the blinding of the value by multiplying the value based on the exponentiation comprises:
performing a modulo operation corresponding to the random number raised to the exponent value modulo the modulus value of the public key to generate an intermediate value; and
multiplying the value with the intermediate value to generate the blinded value.

4. The method of claim 3 , wherein the performing of the cryptographic operation based on the blinded value and the decremented private key exponent value further comprises:
performing an exponentiation of the blinded value raised to the decremented private key exponent value to generate a second intermediate value.

5. The method of claim 4 , wherein the performing of the cryptographic operation based on the blinded value and the decremented private key exponent value further comprises:
decrementing the exponent value of the public key to generate a decremented public key exponent value; and
performing an exponentiation of the second intermediate value raised to the decremented public key exponent value.

6. The method of claim 1 , wherein the cryptographic operation corresponds to an RSA cryptographic operation, and wherein the blinding of the value is associated with reducing susceptibility of a Differential Power Analysis (DPA) leak of an exponent value of a private key that is mathematically linked to the public key.

7. The method of claim 1 , wherein the cryptographic operation corresponds to an RSA cryptographic operation, and wherein the blinding of the value is associated with reducing information present in a result of the RSA cryptographic operation after a fault attack such that there is no information mathematically linked to a private key in the result.

8. A system comprising:
a memory; and
a processor of an integrated circuit operatively coupled with the memory and to:
receive an input for a cryptographic operation;
generate a random number;
perform an exponentiation operation corresponding to the random number raised to an exponent value of a public key that is associated with the cryptographic operation;
receive a second exponent value from a private key that corresponds to the public key;
decrement the second exponent value from the private key to generate a decremented private key exponent value;
perform a multiplication operation with the random number raised to the exponent value and the input to generate a first value; and
perform the cryptographic operation based on the first value and the decremented private key exponent value, wherein the cryptographic operation corresponds to a generation or a verification of a cryptographic signature.

9. The system of claim 8 , wherein the public key comprises the exponent value and a modulus value.

10. The system of claim 9 , the processor is further to:
perform a modular exponentiation operation based on the first value raised to an exponent value of the decremented private key exponent value to generate a second value, wherein the cryptographic operation is further based on the second value.

11. The system of claim 10 , wherein the modular exponentiation operation is based on the Chinese remainder theorem.

12. The system of claim 10 , the processor is further to:
decrement the exponent value of the public key; and
perform another exponentiation operation corresponding to the random number raised to an exponent value of the decremented exponent value of the public key to generate a third value.

13. The system of claim 12 , the processor is further to:
perform another multiplication operation based on the second value and the third value modulo the modulus value to generate a final value, wherein the cryptographic operation is further based on the final value.

14. The system of claim 9 , wherein the cryptographic operation corresponds to an RSA cryptographic operation, and wherein the exponentiation operation and the multiplication operation are associated with reducing susceptibility of a Differential Power Analysis (DPA) leak of an exponent value of a private key that is mathematically linked to the public key.

15. A non-transitory computer readable medium including data that, when accessed by a processor of an integrated circuit, cause the processor to perform operations comprising:
receiving a value corresponding to an input for a cryptographic operation;
blinding the value by multiplying the value based on an exponentiation of a random number raised to an exponent value that is associated with a public key;
receiving a second exponent value from a private key that corresponds to the public key;
decrementing the second exponent value from the private key to generate a decremented private key exponent value; and
performing the cryptographic operation based on the blinded value and the decremented private key exponent value, wherein the cryptographic operation corresponds to an encryption operation or a decryption operation.

16. The non-transitory computer readable medium of claim 15 , wherein the public key comprises the exponent value and a modulus value.

17. The non-transitory computer readable medium of claim 16 , wherein the blinding of the value by multiplying the value based on the exponentiation comprises:
performing a modulo operation corresponding to the random number raised to the exponent value modulo the modulus value of the public key to generate an intermediate value; and
multiplying the value with the intermediate value to generate the blinded value.

18. The non-transitory computer readable medium of claim 17 , wherein the performing of the cryptographic operation based on the blinded value and the decremented private key exponent value further comprises:
performing an exponentiation of the blinded value raised to the decremented private key exponent value to generate a second intermediate value.

19. The non-transitory computer readable medium of claim 18 , wherein the performing of the cryptographic operation based on the blinded value and the decremented private key exponent value further comprises:
decrementing the exponent value of the public key to generate a decremented public key exponent value; and
performing an exponentiation of the second intermediate value raised to the decremented public key exponent value.

Assignees

• Cryptography Res Inc

Inventors

• Tunstall Michael

Classifications

• G06F21/755

  with measures against power attack · CPC title

• H04L9/302

  involving the integer factorization problem, e.g. RSA or quadratic sieve [QS] schemes · CPC title

• G09C1/00

  Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a predetermined system (cryptographic typewriters G09C3/00) · CPC title

• H04L2209/046

  of operations, operands or results of the operations · CPC title

• H04L9/002 Primary

  Countermeasures against attacks on cryptographic mechanisms (network architectures or network communication protocols for protection against malicious traffic H04L63/1441) · CPC title