Jean-Jacques Quisquater
Belgian cryptographer who made zero-knowledge proofs simple enough for children, light enough for smart cards — and who later found himself on the receiving end of a state-sponsored hack.
In 1988 Quisquater and Louis Guillou published the Guillou–Quisquater identification scheme, a zero-knowledge protocol cheap enough to run on the feeble processors of contemporary smart cards. A year later came How to Explain Zero-Knowledge Protocols to Your Children, whose tale of Ali Baba's cave has opened roughly every lecture on the subject since.
At UCLouvain he built a group that worked close to the silicon, and in 2001 he and David Samyde showed that a chip's electromagnetic emanations leak keys just as its power draw does. In February 2014 it emerged that his own computer had been compromised, with traces pointing to the same operation that had hit Belgacom. Intelligence agencies, it seems, read cryptography research too — just not the published versions.