Encryption method and apparatus using composition of ciphers

摘要

A method and associated apparatus for use in a data distribution process to allow an untrusted intermediary to re-encrypt data for transmission from an originator to a message receiver without revealing the data (message) or the cipher to the intermediary. This method uses a composition of two ciphers for re-encrypting the message at the intermediary, without revealing the plain text message or either cipher to the intermediary.