jssecretshare

jssecretshare is a simple proof-of-concept Javascript implementation of Shamir's Secret Sharing scheme. It was specifically designed to interact well with the implementation of Shamir's Secret Sharing scheme found in VIFF.

Do keep in mind this is proof-of-concept code. Also, doing cryptography in Javascript is typically considered to be a Bad Idea (tm), see also the discussion "Javascript Cryptography Considered Harmful".

Dependencies

jssecretshare has a single dependency: jsbn. You will need at least jsbn.js, jsbn2.js, prng4.js, and rng.js

Usage

// Share the secret 42 into 8 shares such that more than 2 
// shares are need to recover the secret.
shares = secretshare.share(42, "9223372045444710599", 2, 8);
// Take three shares to recover the secret
recoveredSecret = secretshare.recombine([shares[0],shares[6], shares[3]],"9223372045444710599");
// Convert BigInteger to Javascript value
secretValue = recoveredSecret.intValue(); // should be 42

Acknowledgements

A large part of the work on this library was done at TNO in a project supported by the "COMMIT/" program.