A cryptographic communication method comprises a step for carrying out cryptographic communication between a sending station and one or more receiving stations by using (1) a ciphertext formed by encrypting a unit of sending information under the intervention of at least a cryptographic key and (2) key-distribution-information...http://www.google.com.au/patents/US5136642?utm_source=gb-gplus-sharePatent US5136642 - Cryptographic communication method and cryptographic communication device
