Patent · US Active

Securing implementation of a cryptographic process having fixed or dynamic keys

US8966285B2 · kind B2 · utility

1Cited by

1References

28Claims

0Family size

Assignee

Apple Inc. · US

Inventors

Augustin J. Farrugia · Cupertino, US
Mathieu Ciet · Paris, FR
Benoit Chevallier-Mames · Paris, FR

Key dates

Filing date	Jan 10, 2011
Grant date	Feb 24, 2015
Priority date	—
Expiry date	Aug 11, 2032

Classification

Technology area (CPC H)Electricity
CPC primaryH04L2209/24
WIPO fieldComputer technology
WIPO sectorElectrical engineering

Abstract

In the field of computer enabled cryptography, such as a keyed block cipher having a plurality of rounds, the cipher is hardened against attack by protecting the round keys by (1) combining several cipher operations using a pair of sub-keys (round keys) into one table look-up, or (2) a key masking process which obscures the round keys by providing a masked version of the key operations for carrying out encryption or decryption using the cipher. This approach is especially advantageous in an insecure “White Box” environment where an attacker has full access to execution of the cipher algorithm, including the algorithm's internal state during its execution.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.