Analysis of the efficiency of the Chor–Rivest cryptosystem implementation in a safe-parameter range

The Chor–Rivest cryptosystem, based on a high-density knapsack problem on a finite field image, was broken by Vaudenay for image, and h admitting a factor s verifying a certain condition. A new set of parameters q and h, which prevent this cryptosystem against Vaudenay’s attack, is presented and the computational aspects of its implementation in the Magma computational algebra system are analyzed.