A Select Glossary of Security-related Terms

Authentication: A way that a computer or service determines if you are who you say you are

Authorization: What are you allowed to see and do, given that you are who you say you are

CA: Certificate authority; a third party that vouches for the identity of the certificate holder

Certificate: A digital document that binds you to a public key; Web sites use it to authenticate their service to your browser

Cookie: Data sent to a computer by a Web server that is sent back to the server to provide customized service when you reconnect

Digital signature: Data added to a message that authenticates the sender and the message by using public-key encryption

https: The "s" at the end means that SSL is being used to encrypt the connection sending the http transmission

Kerberos: An authentication system based on private-key cryptography that eliminates clear text passwords over networks

Message digest: Text scrambled using a one-way mathematical hashing algorithm; MD2, MD4, and MD5 are common

Non-repudiation: Ensuring that the originator of a transaction or message cannot later successfully argue that he did not send it

ssh: Secure Shell; a technology that uses an RSA public-key exchange to authenticate both sides of the network connection

SSL: Secure Sockets Layer protocol for sending encrypted messages on the Internet and Web; used when "https" is specified