Gadi Evron, an information security researcher based in Israel, generally signs his posts to the list with his PGP signature, due to the fact that his email address is constantly used by spammers. Anyone who wants to verify an signed email is actually from the person claiming to send it, can do so. . . .
The trust that encryption generates can be deceptive, one researcher, a regular poster to the full-disclosure vulnerability mailing list, has discovered.

Gadi Evron, an information security researcher based in Israel, generally signs his posts to the list with his PGP signature, due to the fact that his email address is constantly used by spammers. Anyone who wants to verify an signed email is actually from the person claiming to send it, can do so.

What he did not reckon was that someone would try to use his PGP signature inside a spam email to impersonate him.