Thwarting Fault Attacks using the Internal Redundancy Countermeasure (IRC)

A growing number of connected objects, with their high performance and low-resources constraints, are embedding lightweight ciphers for protecting the confidentiality of the data they manipulate or store. Since those objects are easily accessible, they are prone to a whole range of physical attacks, one of which are fault attacks against for which countermeasures are usually expensive to implement, especially on off-the-shelf devices. For such devices, we propose a new generic software countermeasure, called the Internal Redundancy Countermeasure (IRC), to thwart most fault attacks while preserving the performances of the targeted cipher. We report practical experiments showing that IRC successfully thwarts fault attacks on the block cipher PRIDE and on the stream cipher TRIVIUM for which we protect both the initialization and the keystream generation.