This paper (pdf) provides some background information about PGP and explains how to check signatures for validity. "PGP stands for Pretty Good Privacy. It is a computer program that uses mathematical algorithms to encrypt files and protect them from unauthorized access.. . .
This paper (pdf) provides some background information about PGP and explains how to check signatures for validity. "PGP stands for Pretty Good Privacy. It is a computer program that uses mathematical algorithms to encrypt files and protect them from unauthorized access. It is also used to digitally sign and verify documents. Versions of the PGP program are available for most popular computer operating systems--Microsoft Windows, MacOS, and UNIX, to name a few.

Because most of our constituents receive documents that are signed with the CERT/CC PGP key, we focus on the second use. In this paper, we provide some background information about PGP and explain how to check signatures for validity.

A PGP signature appears as a block of seemingly random letters and numbers at the end of the text. A valid digital signature tells the reader of the document that it was written by the owner of the PGP key and the text hasn't been changed in any way since it was signed."