<snip>

...

Or yet another, I like this one best. syslog-ng generates a random value which it will use to generate hash #0, then a copy of this random value is sent to the sysadmin in an email message. Later when somebody wants to check logfile integrity, a copy of this key is needed. This could also be a security risk if that message remains on the same box.

I'm very much a *n?x newbie so this may be an incredibly stupid idea, but FWIW how about PGP encrypting the email using the admin's public key?

Yes, it's a good idea. My solution will be that I'll simply call a script and the local sysadmin can do anything he wants. By default a script which sends a pgp encrypted message will be supplied. -- Bazsi PGP key: http://www.balabit.hu/pgpkey.txt, or finger bazsi@balabit.hu