To check the signature run:
echo | gpg
gpg --auto-key-locate keyserver --keyserver-options auto-key-retrieve parallel-20130514.tar.bz2.sig
gpg --auto-key-locate keyserver --keyserver-options auto-key-retrieve parallel-latest.tar.bz2.sig
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
iEYEABECAAYFAlGSMpYACgkQLGIp4v////F10ACeKh7qqk44tigEen1KEiaHAAn+
0v4AoID0vMxJ0qOZcBrRTPi56hVfU4Fe
=lC2f
-----END PGP SIGNATURE-----