Daniel J. Bernstein
lorecryptographysecurity
The cryptographer and programmer behind qmail and djbdns, and of the curve and cipher designs now widely deployed - and the person who put money behind a security guarantee for his own software.
The guarantee is the part that changed practice: he offered a cash reward for a verifiable security hole in qmail, which was an unusual claim to make in the 1990s and a workable one because the software was small enough to reason about. His designs are opinionated in the same direction - fewer moving parts, less privilege, no configurability that can be misconfigured. He is also a lasting argument in the field about tone: the technical positions and the public disputes with other implementers arrive together in the record, and both belong in it.
Also known as: djb, qmail, curve25519