The library implements a simple PVSS scheme in Rust.
Secret sharing means a dealer can break a secret into secret shares among a group of participants which can reconstruct the secret only by collaboratively joining their parts of the secret. The library also implements threshold cryptography so that the dealer can decide whether all of the receiving participants need to collaborate or if a smaller subgroup of participants is sufficient to reconstruct the secret.
In addition to the plain secret sharing scheme PVSS adds verifiability in the following way: All the parts the secret is split into are encrypted with the receivers’ public keys respectively. The dealer publishes all the encrypted shares along with a non-interactive zero-knowledge proof that allows everbody (not only the receiving participants) to verify that the decrypted shares indeed can be used to reconstruct the secret. The participants then decrypt all their shares and exchange them along with another non-interactive zero-knowledge proof that allows the receiving participant to verify that the share is actually the result of the decryption.
Thus PVSS can be used to share a secret among a group of participants so that either the secret can be reconstructed by the participants who all play fair or a participant that received a faked share can identify the malicious party.
See Github README
the dealer wishes to distribute a secret among participants P1,…,Pn. The dealer picks a randompolynomialp of degree at most t−1 with coefficients in Z_q
A participant represents one party in the secret sharing scheme. The participant can share a secret among a group of other participants and it is then called the “dealer”. The receiving participants that receive a part of the secret can use it to reconstruct the secret Therefore the partticipants need to collaborate and exchange their parts. A participant represents as a Node in the Distributed Public NetWork