 | This article may be too technical for most readers to understand. (September 2013) |
Proactive secret sharing is an underlying technique in Proactive Security Protocols. It is a method to update distributed keys (shares) in a secret sharing scheme periodically such that an attacker has less time to compromise shares and as long as the attacker visits less than a threshold or a quorum group, the system remains secure. This contrasts to a non-proactive scheme where if the threshold number of shares are compromised during the lifetime of the secret, the secret is compromised. The model which takes time constraints into account was originally suggested as an extension of the notion of Byzantine fault tolerance where redundancy of sharing allows robustness into the time domain (periods) and was proposed by Rafail Ostrovsky and Moti Yung in 1991.[1] The method has been used in the areas of cryptographic protocols in secure multi-party computation and in threshold cryptosystems.