HTTP:

The Hyper Text Transfer Protocol is the protocol used between a Web browser and a server to request a document and transfer its contents. The specification is maintained and developed by the World Wide Web Consortium.

HTTPS:

https is ordinary http exchanged over an SSL encrypted session.

IDEA:

A symmetric key block cipher algorithm developed by Xuejia Lai and James Massey in 1991.

MD2:

A secure hash, or message digest, algorithm developed by Ron Rivest.

MD5:

A secure hash, or message digest, algorithm developed by Ron Rivest.

OpenSSL:

OpenSSL is the name now used for the SSL library originally known as SSLeay.

Private Key:

The part of the key in a public key system which is kept secret and is used only by its owner. This is the key used for decrypting messages, and for making digital signatures.

Protocol:

A protocol is an algorithm, or or step by step procedure, carried out by more than one party. Examples are network protocols, in which the steps are intended to ensure reliable transmission of information, or cryptographic protocols, in which the aim is to maintain some form of security relationship between the parties.

Public Key:

The part of the key in a public key system which is distributed widely, and is not kept secure. This is the key used for encryption (as opposed to decryption) or for verifying signatures. Compare private key