Cipher:

Any encryption algorithm. Ciphers can be classified according to whether they are symmetric or public key algorithms, and by whether they operate on their data as a stream or divided into blocks.

Common Name:

A field of an X.509 certificate used for matching against the domain name when validating the certificate.

C2Net:

C2Net is the vendor of the Stronghold server. Stronghold is based on Apache and includes Eric Young's SSL implementation. Crucially, the vendors have obtained a commercial RSAREF licence, to enable use of the server in North America without patent infringement, and have had the server accredited by Verisign. The Stronghold server is able to provide strong encryption, including Triple DES and 128-bit key RC4, to companies worldwide because the relevant code was not developed in the US and is not constrained by US export regulations. C2Net also markets Safe Passage to provide unencumbered 128-bit cryptographic capability for the Netscape and Microsoft browsers and were sponsors of the 1995 Hack Netscape competition, which, amongst other things, helped flesh out the misgivings people had about encryption using 40-bit key lengths.

DES (Data Encryption Standard):

A symmetric key block cipher algorithm developed by IBM and adopted as a standard in the US in 1975.

Digital signature:

A use of public key cryptography to authenticate a message. The private key is used, showing that the signature must have been made by the owner of that key. A secure hash of the entire document is signed, so that any change to the document will invalidate the signature.

DSA:

The Digital Signature Algorithm mandated by the Federal Information Processing Standard FIPS 186. This is a public key system, but unlike RSA it can only be used for making signatures.

Eric Young:

The original developer of SSLeay. Eric is Australian and his work is not encumbered by US export regulations.