Jan Camenisch
Swiss cryptographer behind Idemix, IBM's system for proving facts about an identity without handing over the identity.
Camenisch earned his doctorate at ETH Zurich and spent close to two decades at IBM Research in Zurich. With Markus Stadler he introduced, in 1997, the notation for proofs of knowledge that the literature still uses. With Anna Lysyanskaya he designed CL signatures in 2001–2002: signatures the holder can show again and again without any two showings being linkable.
That work became Idemix (Identity Mixer), a practical take on what David Chaum had sketched in the 1980s: proving "over 18" without revealing a birth date. It never conquered the mass market, but the idea keeps resurfacing in European debates about digital identity wallets. Camenisch later moved to DFINITY.