Joe Kilian
American cryptographer whose 1992 succinct arguments are the grandparent of today's zk-SNARKs.
Kilian did his PhD at MIT under Silvio Micali and showed in 1988 that oblivious transfer is enough, on its own, to build secure multiparty computation. While still a student he had worked with Shafi Goldwasser on the Goldwasser–Kilian method, which uses elliptic curves to produce checkable certificates of primality.
His most durable idea came in 1992: combine a probabilistically checkable proof with a Merkle tree, so the verifier only needs to see a handful of branches rather than the whole proof. Three decades later the blockchain industry runs on that construction, usually without mentioning him. Kilian went on to become a professor at Rutgers.