Authentication Types

http basic - username and password are send in plain text along with the request; subjected to every kind of attacks

http digest - password is hashed with md5; subjected to man-in-the-middle-attack

wsse - username and password encryption, prevents man-in-the-middle-attack, no need for web server cookies; but it requires the server and client to know some form of the password. (Either server holds the clear-text password, or the client has the hashed version of the password)

x.509 - public and private key

oauth2 - requires client id and client secret key

http basic via https - everything is encrypted