AliceBob

AliceBob is a fictional character duo commonly used in cryptography, computer science, and mathematics to represent two hypothetical individuals engaged in a communication or protocol scenario. The names "Alice" and "Bob" originate from early cryptographic literature, where they were introduced to simplify discussions about secure communication methods without relying on real-world examples.

The concept of Alice and Bob emerged in the 1970s, particularly in works discussing encryption and key exchange. In these scenarios, Alice typically represents the sender or initiator of a communication, while Bob serves as the recipient. A third party, often called "Eve," is frequently introduced to symbolize an eavesdropper or adversary attempting to intercept or manipulate the exchange. Variations of this setup, such as "Trudy" or "Mallory," may also appear in later discussions.

AliceBob scenarios are widely used to illustrate concepts like public-key cryptography, digital signatures, and secure messaging protocols. For example, in the Diffie-Hellman key exchange, Alice and Bob establish a shared secret over an insecure channel, demonstrating how cryptographic techniques can enable secure communication despite potential eavesdropping. These examples help clarify theoretical ideas without introducing unnecessary complexity from real-world identities or contexts.

The use of Alice and Bob persists in modern cryptographic research and education, serving as a standardized way to depict abstract communication problems. Their anonymity ensures that discussions remain focused on technical principles rather than specific individuals or scenarios. While the names are now widely recognized, they continue to evolve in informal contexts, sometimes appearing as "Alice and Bob" or simply "AliceBob" in shorthand references.