Yup, jrpt already mentioned it. This is called Shamir's Secret Sharing Scheme. There is a handy CLI tool implementing it: http://point-at-infinity.org/ssss/ htt

Yup, jrpt already mentioned it. This is called Shamir's Secret Sharing Scheme. There is a handy CLI tool implementing it: http://point-at-infinity.org/ssss/ http://point-at-infinity.org/ssss/ This is what's Satoshi's treasure hunt uses (have to find 400 of 1000(?) keys to win the 1 million USD prize)