Loren Kohnfelder is a computer scientist working in public key cryptography.
Kohnfelder invented what is today called public key infrastructure (PKI) in his May 1978 MIT S.B.
(BSCSE) thesis, which described a practical means of using public key cryptography to secure network communications.
[1] The X.509 certificate specification that provides the basis for SSL, S/MIME and most modern PKI implementations are based Kohnfelder's thesis.
In 2021 he published the book Designing Secure Software with No Starch Press.