Secret sharing

Secret sharing is a method in cryptography and information security that allows a secret (such as a cryptographic key, password, or other sensitive information) to be divided into several parts, called "shares." Each share is distributed to different participants, ensuring that no single participant has access to the entire secret. The secret can only be reconstructed when a sufficient number of participants combine their shares.

Proactive secret sharing is an advanced cryptographic technique designed to enhance the security and reliability of secret sharing schemes. In traditional secret sharing, a secret (such as a cryptographic key) is divided into multiple shares and distributed among participants, where a certain threshold of these shares is required to reconstruct the secret. While effective, traditional schemes can be vulnerable to certain attacks, such as when a participant's share is compromised or when all shares are static over time.

Shamir's Secret Sharing is a cryptographic algorithm conceived by Adi Shamir in 1979. It is designed to securely distribute a secret among a group of participants, in such a way that only a certain threshold of them can reconstruct the secret. The main idea behind the scheme is to split the secret into pieces, or "shares," using polynomial interpolation.