| 摘要 |
A method for the secure communication of messages. A first party is provided with a set of numbers that have the property that when encrypted using an RSA encryption key the resulting set of encrypted numbers is of an order substantially smaller than that of the original set. If the encryption key and the original set of numbers are of the order of 200 decimal digits then the resulting set of encrypted numbers may be of the order of 15-30 decimal digits. To communicate a message the first party selects a number from the original set and applies a hashing function to the selected number to obtain a 64 binary bit DES key. The selected number is then encrypted with the RSA key and a message is encrypted with the DES key obtained. The encrypted message and the encrypted selected number are combined and the combined message is sent to a second party who has the corresponding RSA decryption key and knows the hashing function. The second party then decrypts the number, applies the hashing function to obtain the DES key and decrypts the message. Thus the parties may communicate with substantially the security of RSA while significantly reducing the minimum message length which may be securely encrypted. |
