| 摘要 |
A method for protecting a message or document. The method comprises encrypting the message (P) using a first key (a) associated with a first party (Alice); sending the encrypted message to a second party (Bob); encrypting the message using a second key (b) associated with the second party, so that it is encrypted with two keys simultaneously (a+b); sending the encrypted message (a+b) to the first party (Alice); decrypting the message using the first key (a); sending the message to the second party (Bob), the message being encrypted with the second key (b), and using the second key (b) to decrypt the encrypted message, thereby exposing the original message P. |
