| 摘要 |
A system and method for a user to encrypt data in a way that ensures the data cannot be decrypted after a finite period. A number of ephemeral encryption keys are established by a first party, each of which will be destroyed at an associated time in the future (the "expiration time"). A second party selects or requests one of the ephemeral encryption keys for encrypting a message. The first party provides an ephemeral encryption key to the second party. Subsequently, the first party decrypts at least a portion of the message, using an ephemeral decryption key associated with the ephemeral encryption key provided to the second party. At the expiration time, the first party destroys all copies of at least the ephemeral decryption key, thus rendering any messages encrypted using the ephemeral encryption key permanently undecipherable. In an alternative embodiment, a number of ephemeral key servers provide a respective number of ephemeral encryption keys having associated expiration times. A party wishing to transmit an ephemeral message uses the provided ephemeral encryption keys to encrypt at least a portion of the message. The receiver of the message uses at least a subset of the ephemeral key servers to decrypt at least a portion of the encrypted message. At the expiration time(s), at least one of the ephemeral key servers permanently destroys at least one of the decryption keys associated with the provided ephemeral encryption keys. |
