No public key

[zpackard <cyphercell4@gmail.com>]

Hello,

I received the following error after adding back-ports via these
instructions http://pkg-drupal.alioth.debian.org/drupal-on-etch.html

Error
############################################
W: GPG error: http://www.backports.org etch-backports Release: The
following signatures couldn't be verified because the public key is not
available: NO_PUBKEY EA8E8B2116BA136C
############################################

Searched Google and I found a thread where someone had asked if gpgv was
installed. I just checked and I'm running gpgv-1.4.6-2, on Etch, I
recently did a dist-upgrade from Sarge following instructions from the
release notes if that is relevant.

Thanks in advance,

Zeb Packard