Alice and Bob are fictional characters commonly used as a placeholder name in cryptology.
Alice and Bob first appeared in 1978 in a paper on cryptography. A method for obtaining digital signatures and public-key cryptosystems. They wrote
"For our scenarios we suppose that A and B (also known as Alice and Bob) are two users of a public-key cryptosystem".
Instead of saying "How can B send a private message M to A in a public-key cryptosystem?", they chose to represent it with more human friendly names Alice and Bob.
Within a few years, reference to Alice and Bob in cryptological literature became failry common and it even started to appear in Science and Engineering.
Cast of characters#
The world of Alice and Bob grew with time and now there is a complete cast of characters serving some generic purpose.
|Alice and Bob||The original, generic characters. Generally, Alice and Bob want to exchange a message or cryptographic key.|
|Carol||The generic third participant.|
|Eve||The eavesdropper, who is usually a passive attacker|
|Grace||A government representative|
|Mallory||Malicious attacker. Unlike the passive Eve, Mallory/Mallet is an active attacker. usually participating in man-in-middle attacks|
|Trent||A trusted arbitrator, who acts as a neutral third party|