Transient-key cryptography

In a transient-key system, private keys are used briefly and then destroyed, which is why it is sometimes nicknamed “disposable crypto.” Data encrypted with a private key associated with a specific time interval can be irrefutably linked to that interval, making transient-key cryptography particularly useful for digital trusted timestamping.

Transient-key cryptography was invented in 1997 by Dr. Michael Doyle of Eolas, and has been adopted in the ANSI ASC X9.95 Standard for trusted timestamps.

Both public-key and transient-key systems can be used to generate digital signatures that assert that a given piece of data has not changed since it was signed.

In a traditional public key system, the public/private keypair is typically assigned to an individual, server, or organization.

A web of interconnected cross-certifying servers in a distributed environment creates a widely witnessed chain of trust that is as strong as its strongest link.

Within a transient-key network, the archive is a logical database that can be stored and replicated on any system to enable verification of data that has been timestamped and signed by transient keys.

During an interval, the transient private key is used to sign data concatenated with trusted timestamps and authenticity certificates.

Transient-key cryptography was invented in 1997 by Dr. Michael D. Doyle of Eolas Technologies Inc., while working on the Visible Embryo Project[1][2][3] and later acquired by and productized by ProofSpace, Inc.

Transient-key cryptography is the predecessor to Forward secrecy and formed the foundation of the forward-signature-chaining technology in the Bitcoin blockchain system.