Editing Ralph Merkle (section)

==Contributions==
While an undergraduate, Merkle devised [[Merkle's Puzzles]], a scheme for communication over an [[insecure channel]], as part of a class project at UC Berkeley.<ref>{{cite book |last1=Garfinkel|first1=Simson|title=Pretty Good Privacy|publisher=O'Reilly and Associates|year=1994}}</ref> The scheme is now recognized to be an early example of [[public key cryptography]]. He co-invented the [[Merkle–Hellman knapsack cryptosystem]], invented [[cryptographic hashing]] (now called the [[Merkle–Damgård construction]] based on a pair of articles published 10 years later that established the security of the scheme), and invented [[Merkle tree]]s. The Merkle–Damgård construction is at the heart of many hashing algorithms.<ref name="Hash Functions Paper">{{cite web|url=http://crypto.stanford.edu/~mironov/papers/wuf.pdf  |title=Hash Functions: From Merkle–Damgård to Shoup|author=Ilya Mironov}}</ref><ref name="Merkle–Damgård Paradigm Collision Resistance">{{cite web|url=https://www.youtube.com/watch?v=jxiOCfFZZcM |archive-url=https://ghostarchive.org/varchive/youtube/20211211/jxiOCfFZZcM| archive-date=2021-12-11 |url-status=live|author=intrigano|title=Cryptofraphy (sic) The Merkle Damgard Paradigm collision resistance|website=[[YouTube]]}}{{cbignore}}</ref> 
At [[Xerox PARC]] Merkle designed the [[Khufu and Khafre]] [[block cipher]]s and the [[Snefru]] hash function.