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-tomcat-13.0rc3-wheezy-amd64.iso.sig gpg: Signature made Fri Sep 13 09:34:33 UTC 2013 using RSA key ID A16EB94D gpg: Good signature from "Turnkey Linux Release Key" For your convenience we also include file checksums: * sha1sum 2c841ec0df0dd238ef95552dc6cca39a561fb4d2 * md5sum 55a1d89b03a61da747515df0592a0c5e 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) iQEcBAABAgAGBQJSMtwfAAoJEIXCXpWhbrlNIuUH/2rJCZ9epBqGfjo9ZKoJFCP2 tC85c6VxOXNj9SMJhAc2vfmnH/xjYZIOVVTPUoOfbTfF9N/jsn5NeholWaPKb/8Q BUhBGzZHvMFlUI38IXHMTdbqKUM9tn54oN5PfhY782gClyjEPc84Zin4ioDull36 Y3vxJTTZiz6r57pl7YA2halzzURRbEZmkL2r7Oqih9x//vsrQNO9ivUVPad35ZtM pPAiHPB51wvKj8xdI92lVFS1i7SOBH2/viXJMwfcXH08xG2OaMNA9lNGmW64QW3k fkE+l6R2OrZqxGADChBVBrRTCOwM9MLDXfiaro8RgDwgp7QAAaxcsnNFlTepMyY= =zH+r -----END PGP SIGNATURE-----