If you want to send me an encrypted message or verify a digital signature on a message from me, use my current PGP key, available here and on the keyserver.
Use this key with software that implements the OpenPGP standard. One such package is GnuPG, the GNU Privacy Guard, which is free.
This key supersedes my old public key from 1999, which I revoked on 2012-11-01. Signatures made before that date are valid.