US 11,115,210 B2 · Systems and methods for masking RSA operations

Abstract

Presented are systems and methods for protecting secret data that is stored in memory to prevent unauthorized access and data manipulation. Various embodiments may be applied to hide or mask an RSA exponent used for public key cryptography and stored in a cryptographic hardware block that uses a non-erasable working memory for computations. In certain embodiments, masking RSA exponents is accomplished by a two-step process that combines a specifically calculated, random and secret value with the secret exponent. The random value is stored in an erasable memory, such that in case of attack, both the erasable memory and the non-erasable memory do not leak any embedded secrets. The additional expenditure of memory resources only insignificantly affects system performance.

Claims20

Dependent claims

A method for protecting confidential data, the method comprising:

receiving a secret value and a random value;
at a secure device, adding the random value to the secret value to obtain a masked value;
storing the masked value in a non-secure memory, the non-secure memory being external to the secure device;
using the masked value to compute an intermediate value;
erasing the masked value from the non-secure memory, such that in the event of an attack neither one of the secret value and the random value can be recovered from the non-secure memory;
loading an exponent value into the non-secure memory;
and
using the intermediate value and the exponent value to compute a final value.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application

16/039,014Filed 18 Jul 2018

Priority

FR 17575557 Aug 2017

Published

US 2019/0044717 A17 Feb 2019

Granted

7 Sep 2021

Term ends

Not estimatedThe source records don’t support an estimate.

Classification12 codes

H04L 9/302
Underlying computational problems or public-key parameters: involving the integer factorization problem, e.g. RSA or quadratic sieve [QS] schemes
G06F 21/602
Protecting data: providing cryptographic facilities or services
G09C 1/00
Apparatus or methods whereby a given sequence of signs
H04L 9/002
Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols: countermeasures against…

Systems and methods for masking RSA operations

Life of this patent

Systems and methods for masking RSA operations

Life of this patent

Abstract

Claims20