| 摘要 |
A method and system are provided for timed-release cryptography. A sender encrypts data in a timed-release fashion such that a receiver based on information exchanged with a server decrypts the encrypted data at or after a release time without revealing to the server any information about the sender, the data, and the release time. In one embodiment, the sender encrypts a key and a release time based on a public key of the receiver and encrypts the data based on the encrypted key. The server determines a condition, which is a function of the encrypted key, the encrypted release time, and a current time. The server then sends the condition to the receiver using a conditional oblivious transfer method. If the current time as determined by the server is greater than or equal to the release time, the receiver determines the encrypted key based on the condition. The receiver then uses the encrypted key to decrypt the encrypted data. However, if the current time is less than the release time, the receiver fails to determine the encrypted key based on the condition, and thus, fails to decrypt the encrypted data. |
