Encryption method and apparatus

Abstract

An encryption method and apparatus for implementing an overlapping operation, a variable clock operation, and a combination of the two operations. In the encryption method based on an overlapping operation technique, first, first through N-th fault sources effect first through N-th rounds of a first hardware engine to output a first cipher text. Thereafter, the second through (N+1)th fault sources effect first through N-th rounds of a second hardware engine, respectively, to output a second cipher text. The first and second cipher texts are compared to each other, and if the first and second cipher texts are identical, the first or second cipher text is output. The first and second hardware engines operate according to a data encryption standard (DES) algorithm. As described above, if the first and second cipher texts are identical, the first or second cipher text is output. Thus, a highly stable encryption algorithm is provided.

Dependencies are inferred from the claim text.