Analyzing a Cryptographic Protocol
Web services such as email, photo, social networks, internet commerce, and online banking require that entities authenticate themselves. Scrooge McDuck must be sure that he (it?) is communicating with the bank, and not with some bad guy with a look-a-like web page. Likewise, when the bank gets the request “transfer 5 gazillions from my account to the Beagle Boys” from “Scrooge,” the bank must be sure that it is communicating with Scrooge and not with the Beagle Boys.