There is considered implementation of the plan-ahead share-key deniable encryption algorithms that produce the cryptogram that satisfy criterion of the computational indistinguishability from probabilistic encryption of the fake message. This paper introduces a general design of the pseudoprobabilistic block ciphers. The proposed method includes encryption of the secret message block and the fake message block followed by a transformation procedure mapping the pair of intermediate ciphertext blocks into a single block of the output ciphertext. The transformation procedure represents solving the system of two linear congruencies.