Tatu Ylönen of
Finland (born 1968) wrote the
RFC and first implementation for the
Secure Shell (
SSH) protocol while working as a researcher at the
Helsinki University of Technology in 1995.
To quote the RFC (draft-ylonen-ssh-protocol-00.txt): SSH (Secure Shell) is a program to log into another computer over a network, to execute commands in a remote machine, and to move files from one machine to another. It provides strong authentication and secure communications over insecure networks.
The code and specs were released to the public at large and gained instant popularity in addressing the inherent insecurities of the Internet. Secure Shell is still the de facto method for securing remote shell connections to hosts.
In addition to earlier IT companies, he founded SSH Communications Security corporation in 1995 which started the commercial development of the Secure Shell products. The company has developed several cryptographical products in the realms of Secure Shell, IPSec, PKI, TLS, VPNs etc. He is still the major shareholder of the company and actively involved in product development.
Tatu Ylönen holds a Licentiate of Technology diploma from the Helsinki University of Technology. As a person he's a very easy-going, polite and down-to-earth character, albeit often quite immersed in his thoughts.