Poul-Henning Kamp

Poul-Henning Kamp (born 1966) is a Danish computer software developer known for work on various projects. He currently resides in Slagelse, Denmark.

Poul-Henning Kamp has been committing to the FreeBSD project for most of its duration. He is responsible for the widely used MD5crypt implementation of the MD5 password hash algorithm,

a vast quantity of systems code including the FreeBSD GEOM storage layer, GBDE cryptographic storage transform, part of the UFS2 file system implementation, FreeBSD Jails, malloc library, and the NTP timecounters code.

He is the lead architect and developer for the open source Varnish cache project, an HTTP accelerator and Ntimed, an NTP daemon meant to replace ntpd.

His dispute with electronics manufacturer D-Link in which he claimed they were committing NTP vandalism by embedding the IP address of his NTP servers in their routers was resolved on 27 April 2006.

Poul-Henning Kamp has published a substantial number of articles over the years in publications like Communications of the ACM and ACM Queue mostly on the topics of computing and time keeping. A selection of publications:

• USENIX ATC 1998 FREENIX track, "malloc(3) Revisited"
• USENIX BSDCon 2003, GBDE-GEOM Based Disk Encryption
• USENIX BSDCon 2002, Rethinking /dev and devices in the UNIX kernel
• ACM Queue: Building Systems to be Shared Securely
• ACM Queue: You're doing it wrong
• ACM Queue: A Generation Lost in the Bazaar
• Communications of the ACM 2011: The Most Expensive One-Byte Mistake
• Communications of the ACM 2011: The One-Second War