| 摘要 |
A method of associative encryption and decryption which can be used to convert plaintext to ciphertext is disclosed. The method incorporates the steps of selecting a master key and specific set of algorithms; providing means for generating a set of sub-keys for performing a first operation and sub keys for performing a second operation and operating on plaintext with specific algorithms and sub keys selected from said set of algorithms and set of sub keys. The order of operation, selection of algorithm, selection of master key and generation of sub keys is such that encryption and decryption of plaintext using the method is associative. The first operation may be a permutation operation and the second operation may be a substitution operation. In a second embodiment there is provided a system of secure communication between two parties, the system comprising the steps of a first party, party 1, encrypting a message using a first private key and sending it to a second party, party 2; party 2 further encrypts the message using a second private key, which is associative with the first private key, and returns the twice encrypted message to party 1; party 1 partially decrypts the twice encrypted message using the first private key and sends the resulting once encrypted message to party B; party B then decrypts the encrypted message using the second private key to obtain the original plaintext. |
