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-concrete5-13.0-wheezy-amd64.iso.sig gpg: Signature made Tue Oct 15 15:02:23 UTC 2013 using RSA key ID A16EB94D gpg: Good signature from "Turnkey Linux Release Key" For your convenience we also include file checksums: * sha1sum af15bf1cf33d45f98bb3ddad85ee9e065c83f946 * md5sum b1c83a940bccc2587e183615c5bf4dc5 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) iQEcBAABAgAGBQJSXVj2AAoJEIXCXpWhbrlN7HIIAKkMs3nzG1yLTizPjyN/KAKj LG0zCVEq0Ch/XkHoc8JfG+kzUSSgaua+oz0fkT3ZwPfS7ogzFNfRtqMkeS5mpDfx 8EszOIkSxhwDFBFaqPAd7DkLDYJI0L1M8yFy9KFypay6CyN9i0KcSxvEBi/yEYnK 1AhonAzU6D2zG541eQXfc7F8DFfUV9JB9CtH5Fk8bDahjcsolSckR+SNo7LFVUP0 NcCjGegtWIhafu+z2K0CY/d505GwXGEXJ23AlBP+u0uw5R/4PrgTbbSyiGI9DaIh +BVllw6KDvheqDnyJE7Q8NB7cDPzjphtyNATEGk1zMb4v06xi9MuNUpcdJW15uI= =5Qhe -----END PGP SIGNATURE-----