This papers explores the relations between the generation of solved instances of optimization problem and the design of private key cipher. A class of ciphers derived from complementary slackness conditions of multiconstraint knapsack problem (MKP) are presented and discussed. It is shown that under plaintext attack, any algorithm that predicts the embedded key sequence generator of the ciphers also solves a sequence of instances of MKP. It is also shown that even under P=NP and additional assumption, security under plaintext attack of the proposed ciphers is equivalent to their associative key sequence generator.
Journal of Information and Optimization Sciences 16(2), pp.335-350