Analytical Observations on Knapsack Cipher 0/255

Abstract: We observed few important facts that concerns with the new proposal of knapsack cipher 0/255, recently published by Pham [1]. The author claimed that the time complexity for solving new improved trapdoor knapsack is O(256^N). In this paper, we show that the knapsack cipher 0/255 can be solved in the same time that is required for solving the basic knapsack-cipher proposed by Merkle and Hellman [2]. In other words we claim that the improved version proposed by Pham [1] is technically same as the basic Merkle and Hellman Knapsack-based cryptosystem.