Abstract
The study of the knapsack PKC is important from both practical and theoretical standpoints. We proposed a double-sequence knapsack PKC on the basis of MH PKC. We also proposed a single-sequence knapsack PKC using the Chinese remainder theorem on the basis of this scheme. In this paper, we explain the double-sequence knapsack PKC and the single-sequence knapsack PKC. We describe examples of trapdoors based on the conventional trapdoors. We evaluate the breaking rate of the double-sequence knapsack PKC and the single-sequence knapsack PKC with the low-density attack by computer experiments.