Algorithm Uses and Properties
Algorithms reversibly converting data (plaintext) into unintelligible form (ciphertext).
- E(P) = C, and then D(C) = P
- Only knowledge of "secret" allows recovery.
- Kerckhoffs's doctrine (19th century):
not based on the secrecy of the algorithm.
- E(P, EK) = C, and then D(C, DK) = P
- Building blocks for services/protocols that provide other assurances such as