| 摘要 |
A method for encrypting a message M of IM-bit length, includes the steps of a) providing a first random bit sequence of IR-bit length, IR≧IM; b) subdividing the message M into unitary message strings of IS-bits, wherein IS≰IM; c) for each unitary message string, executing an XOR-operation of the unitary message string with IS bits of the first random bit sequence for generating an encrypted unitary string; and d) assembling the encrypted unitary strings into a cipher text. According to the invention the assembly of the cipher text is such, that the positions of the encrypted unitary strings in the cipher text are randomly permuted with respect to the positions of the corresponding unitary message strings in the message. In other words, the step of assembling the encrypted unitary strings into a cipher text includes the step of randomly permuting the positions of the encrypted unitary strings in the cipher text with respect to the positions of the corresponding unitary message strings in the message. |
