The author working on computer and network security at Microsoft Research in Cambridge, UK. Prior to joining Microsoft in 2001, he was at Helsinki University of Technology (HUT) where he managed and participated in several industrial research projects and lectured a course on computer security and cryptography. He received his Master's degree at HUT in 1996 and doctoral degree in 2000.

The author is interested in all areas of security protocol engineering from threat analysis, design and specification to implementation and testing. The focus of his current research is on the security of mobility protocols. He is one of the key designers of the Mobile IPv6 security protocol and is participating in the development of other protocols in the IETF.