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-java-13.0rc3-wheezy-amd64.iso.sig gpg: Signature made Fri Sep 13 07:34:34 UTC 2013 using RSA key ID A16EB94D gpg: Good signature from "Turnkey Linux Release Key" For your convenience we also include file checksums: * sha1sum 275442a1605a329505c9b7bd88a57768ae828a2c * md5sum 420251365f65bc7f51401b10f151be7e 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) iQEcBAABAgAGBQJSMr/9AAoJEIXCXpWhbrlNC9UH/AokC3/bnSMapYL/19L4jK6b bOsZnOur+SXA6iL57paxhDaucwIWCaPUzRXBn+8OoJ0ujPYs1BXZoSKiOXr3Dcdt mUpSrQ/BOfgU9OPFfEnOZMnB95PwztweWvgNy1CBpDTQduOaUiVsRcnp8NXbVFI5 5VU4urjfAhcHFRHe/j1yUAWFjxk7LA3jwh9B6800QbSniJPhPI1T88vQu+SNCMoJ auTcN4M3BSs7OSEdmNR68BGhvehuJ8Kskdj2e6THTzf5DAMR7oO4UdftIxOescl6 Toc+MCEC5JopIoFzVq52jOx0Yl7kLia8P6ftAKzRh7D3SGetL/y2FA44mLP76x4= =ewZL -----END PGP SIGNATURE-----