This signature file may be used to cryptographically verify file integrity, like this:: $ gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 0xA16EB94D $ gpg --list-keys 0xA16EB94D pub 2048R/A16EB94D 2008-08-15 [expires: 2023-08-12] uid Turnkey Linux Release Key $ gpg --verify turnkey-appengine-go-13.0-wheezy-amd64.iso.sig gpg: Signature made Tue Oct 15 14:41:48 UTC 2013 using RSA key ID A16EB94D gpg: Good signature from "Turnkey Linux Release Key" For your convenience we also include file checksums: * sha1sum f73e8a7e61a6d99e7c0bba95f44d0c274320008d * md5sum 15fe1c06587634c2d5299c436945ccfe You can calculate these on your end and compare to check for errors, but cryptographic verification is recommended for security reasons. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQEcBAABAgAGBQJSXVQmAAoJEIXCXpWhbrlNofEH/2kDTYEBn/hoCbRo0gdl0e21 NIZmA6au87PKWquDmr9+LvHOq5ok89oNjFAUSOtmyO4dg4hZ6kKKFTT2crK1F/GN /ubcPORaF7DFJ3QrM2Bqpl9pIlWHiqYjNk5LU3lwmKCRnaAwQBO0HmxpvpTYx0/W e4cNZJ4rezMQtteOCFnNoj7Z6cTJnzO/mT4zBngYqkwwTDSSkfrJ1y7FHucLY6ne /sM3LFKPQEPVG6h5T+obSBlkU9iDx9RHPyYHHyCJ0h095WsfjPxG0aIxnml7rLoN J+o/5h68UI4DpKdjlqsY1JrwkwzRWspLNzIHKoY+eORjpLjpQPTcREOhm0M8HQw= =0OVT -----END PGP SIGNATURE-----