This is one of the best (simple) explanations of Shamir's Secret Sharing Scheme [0] which has a solid working implementation [1]<p>[0]: <a href="https://en.wikipedia.org/wiki/Shamir%27s_Secret_Sharing" rel="nofollow">https://en.wikipedia.org/wiki/Shamir%27s_Secret_Sharing</a><p>[1]: <a href="http://point-at-infinity.org/ssss/" rel="nofollow">http://point-at-infinity.org/ssss/</a>