Hashing

• One-way operation a.k.a. Message Digest

• Source data of arbitrary size results in a small fixed size hash/digest

• No two sources (almost) result in the same hash (collision-resistant)

• A small change in the source results in a large change in the hash or digest

• Computationally infeasible to derive the source from any given hash, “one-way”

• Examples are MD5 and the SHA family