Reversible data mixing procedure for efficient public-key encryption

This paper describes a data mixing method for encrypting a plaintext block using a block encryption algorithm (such as Elliptic Curve, RSA, etc.) having a block size smaller than that of the plaintext block. The process of encrypting a plaintext block consists of first mixing the plaintext block and then encrypting a portion or all of the mixed plaintext block. The mixing method is a reversible procedure which performs a ÒcompleteÓ mixing of the plaintext block such that no secret bit in the plaintext block can be determined unless every bit in the mixed plaintext block is known. The ÒmixingÓ of the plaintext is done in such a way that encrypting only a small portion of the mixed plaintext will still provide the same level of protection as if the entire plaintext was encrypted.