A Time-lock puzzle, or Time released cryptography encrypts a message that cannot be decrypted until a specified amount of time has passed.
The concept was first described by Timothy C. May,[1] and a solution first introduced by Ron Rivest, Adi Shamir, and David A. Wagner in 1996.
[2] Time-lock puzzle are useful in cases where confidentiality of information is determined by time, such as an diarist who does not want their views released until 50 years after their death, an auction where bids are sealed until the bidding period is closed, electronic voting, and contract signing.
[1][3] They can additionally be used in creating further cryptographic primitives, such as verifiable delay functions and zero knowledge proofs.
[3] Time released cryptography can be achieved through several different mechanisms.