Share It

Description

Scrooge McDuck loves treasure hunts, and he regularly organizes them. He usually buries a real treasure somewhere and invites the hunters to discover the GPS coordinates through various puzzles and riddles to be solved. Scrooge recently shared the coordinates of a buried golden owl with some “trustworthy” friends (who are obviously not supposed to participate to the hunt) so that they are able to recover the treasure in case anything happens to him. Unfortunately, his cupid nephew Donald stole the owl and disappeared with it …

Scrooge swore to never go on that road again! His other passions being programming and mathematics, he decided to implement a tool named share-it by optimizing the source code sss.c of an obscure cryptographic library called libecc. Thanks to his tool, he can share his secret with several persons (including some ushers) by fixing a quorum of minimum shares to be present in order to reveal the secret. This allows Scrooge to be fairly confident that if he shares his secret using the tool with a minimum of persons, it will stay safe: in order to prevent potential malicious collusions of shares holders and force them to be revealed, he neither communicated the quorum size nor the total number of generated shares. Rumours mention around sixty distributed shares though.

Evil minded Donald stole a share share_0.bin as well as the tool binary share-it from an inadvertent cousin. He is convinced that with these sole elements, he can find the secret place where Scrooge recently buried the golden unicorn. Putting faith in your expertise, he promises you half the prize: will you be able to help him?