GRACE - 2016

Section: New Results

Update on the Chor-Rivest cryptosystem

The Chor-Rivest cryptosystem from the 90's was “broken” by Vaudenay. However, Vaudenay's attack applies only for the range of parameters originally proposed. The major recent breakthrough in discrete logarithm computations enable to redesign the system with a completly different range of paramaters, possibly thwarting Vaudenay's attack. D. Augot and C. Barbin tried to find a new attack against this discrete log and knapsack-based cryptosystem, using the Sidelnikov-Shestakov algorithm for recovering a Reed-Solomon code. Apparently, our new attack does not outperform S. Vaudenay's original attack, and it may be possible that the Chor-Rivest could be redesigned in a secure way.