Public-key cryptography (Diffie-Hellman)
Criptografía de clave pública (Diffie-Hellman)
- Date
- 1976 · confidence high
- Place
- Stanford University, California, United States
- Credited to
- Whitfield Diffie and Martin Hellman, with Ralph Merkle; earlier secret discovery at GCHQ (James Ellis, Clifford Cocks, Malcolm Williamson, 1970-1974)
- People
- 👤 Martin Hellman1945–👤 Ralph Merkle1952–👤 Whitfield Diffie1944–
- Field
- Knowledge & symbols
⚠️ Disputed: the sources disagree.
What it is
Method for two parties to agree on a secret key over a public channel without having met before. It solved the key-distribution problem and founded civilian cryptography.
Britain's GCHQ discovered it in secret between 1970 and 1974 and did not declassify it until 1997.
What it led to
- E-commerce and secure communications without prior trust
- The crypto wars between governments and citizens over encryption
- Digital signatures, Bitcoin and digital identity
- RSA
- digital signatures
- elliptic-curve cryptography
- TLS protocols and blockchain
Built on
- Modular arithmetic and quadratic reciprocity1801
- Galois theory and group theory1832
- Bombe (Enigma codebreaking machine)1938–1940
- number theory
- Shannon's information theory
- DES
- complexity theory
- Shannon (perfect secrecy)
Made possible
- RSA encryption1977
- Needham–Schroeder protocol1978
- Zero-knowledge proofs and elliptic-curve cryptography1985
- PGP (Pretty Good Privacy)1991
- SSL/TLS and HTTPS1994-1995
- E-commerce (Amazon, eBay)1994-1995
- Paillier cryptosystem1999
- AES (Rijndael) encryption standard1998-2001
- Tor onion routing2002
- Curve255192005
- Bitcoin and blockchain2008-2009
- Mobile internet messaging (WhatsApp) with end-to-end encryption2009
- Cyberweapon (Stuxnet)2010
- cryptocurrencies