12 — People: Cryptographers and Cryptanalysts

Brief biographies of the main actors. Ordered chronologically by impact, with a cross-reference by category at the end.

Antiquity and Medieval

Al-Khalil ibn Ahmad al-Farahidi (~718–786)

Arab philologist, Basra. Kitab al-Mu'amma (Book of Cryptographic Messages) — first known treatise on permutations in cryptography.

Al-Kindi (~801–873)

Arab polymath, Baghdad (House of Wisdom). Risalah fi Istikhraj al-Mu'amma — invents frequency analysis. Father of cryptanalysis.

Leon Battista Alberti (1404–1472)

Italian Renaissance polymath (conceptual architect of the Trevi Fountain, author of treatises). Father of Western cryptography with De Cifris (1466) — polyalphabetic cipher disk.

Johannes Trithemius (1462–1516)

German abbot, occultist. Polygraphia (1518) — tabula recta, basis of tabular polyalphabetic ciphers.

Giovan Battista Bellaso (1505–after 1568)

Italian cryptographer. True inventor of the "Vigenère cipher" — La Cifra del Sig. Giovan Battista Bellaso (1553).

Blaise de Vigenère (1523–1596)

French diplomat. Published Traicté des Chiffres (1586) — synthesized and extended Bellaso's work. His name became wrongly associated with the cipher.

Antoine + Bonaventure Rossignol (17th century)

Father and son, cryptographers to Louis XIV. Invented the Grand Chiffre — a nomenclator unbroken until Bazeries in 1893.

Telegraph era (19th century)

Charles Babbage (1791–1871)

English mathematician, mechanist. Inventor of the Difference Engine. Broke Vigenère in 1854 but did not publish (likely for national security reasons).

Friedrich Kasiski (1805–1881)

Prussian officer. Die Geheimschriften und die Dechiffrierkunst (1863) — public method for breaking Vigenère.

Charles Wheatstone (1802–1875)

British inventor (telegraph, microphone, stereoscope). Invented the Playfair cipher (1854), promoted by Lord Playfair.

Auguste Kerckhoffs (1835–1903)

Dutch-French linguist and cryptographer. La Cryptographie Militaire (1883) — Kerckhoffs's 6 principles, especially: the system must be secure even when everything except the key is known. Conceptually, the father of modern cryptography.

First half of the 20th century

Gilbert Vernam (1890–1960)

Bell Labs engineer. Patented the XOR cipher with paper tape (1917, US 1,310,719). Basis of the One-Time Pad.

Joseph Mauborgne (1881–1971)

Major general, US Army Signal Corps. Co-inventor of the OTP — insisted on a single-use random key combined with Vernam's cipher.

Lester S. Hill (1891–1961)

American mathematician. Cryptography in an Algebraic Alphabet (1929) — Hill cipher, the first purely algebraic cipher.

William Friedman (1891–1969)

Father of American cryptanalysis. Riverbank Labs, then SIS (Signal Intelligence Service). Led the breaking of Japanese Purple (1940). Introduced rigorous statistical methods (index of coincidence, 1922). Married to Elizebeth Smith Friedman, also a pioneering cryptographer.

Elizebeth Smith Friedman (1892–1980)

William's wife. Broke rum-runners' ciphers during American Prohibition and, in WWII, the ciphers of Nazi spies in Latin America. Spent years in obscurity while men received credit; her biography has been rehabilitated in recent books.

Arthur Scherbius (1878–1929)

German engineer. Patented the commercial Enigma in 1918.

Marian Rejewski (1905–1980)

Polish mathematician, Biuro Szyfrów. In 1932, with Jerzy Różycki and Henryk Zygalski, achieved the first structural break of military Enigma using permutation theory. Built the Bomba kryptologiczna (1938).

Jerzy Różycki (1909–1942)

Co-author of the Polish break of Enigma. Died in a shipwreck in 1942.

Henryk Zygalski (1908–1978)

Co-author of the Polish break. After the war, lived in England.

Alan Turing (1912–1954)

English mathematician. Bletchley Park 1939–1945. Redesigned the British Bombe to exploit cribs. Father of theoretical computer science (Turing machines, halting problem, Turing test). Persecuted for his homosexuality by the British government; suicide in 1954. Rehabilitated posthumously; official apology in 2009; royal pardon in 2013.

Gordon Welchman (1906–1985)

Bletchley Park mathematician. Added the diagonal board to the Bombe (a fundamental improvement). Hut 6. Author of The Hut Six Story (1982).

Hugh Alexander (1909–1974)

British chess champion, Bletchley Park (Hut 8 naval Enigma). After the war, head of cryptanalysis at GCHQ until 1971.

Bill Tutte (1917–2002)

Bletchley Park mathematician. Derived the structure of the Lorenz SZ40/42 ("Tunny") solely by observing ciphertext in Jan 1942 — considered one of the greatest mathematical achievements in history. Later career in graph theory, Waterloo, Canada.

Max Newman (1897–1984)

Bletchley Park mathematician. Led the "Newmanry" — the team that built and operated the Colossus.

Tommy Flowers (1905–1998)

Engineer at the Post Office Research Station, Dollis Hill. Designed and built the Colossus (1943) — the first programmable digital electronic computer. Operational in Dec 1943.

Frank Rowlett (1908–1998)

American mathematician, SIS. Led the breaking of Purple alongside Friedman. Designer of SIGABA. Career at the NSA until 1965.

Post-WWII / Shannon era

Claude Shannon (1916–2001)

Bell Labs. Father of information theory. Communication Theory of Secrecy Systems (1949) — defines perfect secrecy, proves the OTP theorem, introduces confusion/diffusion. A Mathematical Theory of Communication (1948) creates modern information theory. PhD MIT on Boolean algebra applied to circuits (1937) — his master's thesis changed computer design.

Horst Feistel (1915–1990)

German-American physicist, IBM. Invented the Feistel structure in 1971. Co-designed Lucifer, predecessor of DES.

Don Coppersmith (1950–)

IBM mathematician. Co-designed DES (with Feistel). The NSA knew of differential cryptanalysis; it tuned the S-boxes to resist it. Coppersmith's method (1996) — lattice attack on RSA with small secrets. Multiple IBM/ACM awards.

Public-key revolution

Whitfield Diffie (1944–)

Computer scientist. Co-author of New Directions in Cryptography (1976) with Hellman. ACM Turing Award 2015 (with Hellman). VP of security at Sun, later MIT.

Martin Hellman (1945–)

Stanford professor. Co-author with Diffie. ACM Turing Award 2015. Worked on nuclear escalation and international security after retirement.

Ralph Merkle (1952–)

Stanford PhD. Invented Merkle's Puzzles (1974, conceptual "non-secret encryption"). Merkle trees (1979) — basis of Git, Bitcoin, Certificate Transparency. Merkle signatures (hash-based, basis of SPHINCS+/SLH-DSA). Career in nanotechnology (Xerox PARC).

James Ellis (1924–1997, GCHQ)

British engineer. Original concept of "non-secret encryption" in 1969 (classified, declassified 1997).

Clifford Cocks (1950–, GCHQ)

British mathematician. Discovered an analogue of RSA in 1973 (classified until 1997). Career at GCHQ.

Malcolm Williamson (1950–, GCHQ)

Analogue of DH in 1974 (classified). Together with Cocks and Ellis, anticipated DiffieHellmanRSA but in secret.

Ron Rivest (1947–)

MIT professor. Co-author of RSA (1977). Invented MD2 (1989), MD4 (1990), MD5 (1991), RC4 (1987), RC5/RC6, ChaCha hint. ACM Turing Award 2002.

Adi Shamir (1952–)

Weizmann Institute professor. Co-author of RSA, Shamir secret sharing (1979), differential cryptanalysis (1990 with Biham). ACM Turing Award 2002.

Leonard Adleman (1945–)

USC professor. Co-author of RSA. Pioneer in DNA computing (1994). Coined "computer virus" (1983, with Fred Cohen). ACM Turing Award 2002.

Taher ElGamal (1955–)

Stanford PhD under Hellman. Invented the ElGamal cryptosystem (1984). Original designer of SSL at Netscape (1995). Career in industrial security.

Neal Koblitz (1948–)

Mathematician, Univ. of Washington. Proposed ECC independently of Miller (1985). Vocal critic of academicized "provable security" — wrote several controversial papers.

Victor Miller (1947–)

IBM researcher. Proposed ECC at CRYPTO '85, independently of Koblitz. Co-inventor of Miller's algorithm for the Tate pairing (basis of pairing-based crypto).

Shafi Goldwasser (1958–)

MIT/Weizmann professor. Co-invented zero-knowledge proofs (1985, with Micali and Rackoff), probabilistic encryption (1982), the GMR signature scheme. ACM Turing Award 2012 (with Micali). Pioneer in formal definitions of security.

Silvio Micali (1954–)

MIT professor. Co-inventor of ZKP, IBE pioneer. ACM Turing Award 2012. Founder of the Algorand blockchain.

Charles Rackoff (1948–)

Co-author of the original ZKP paper (Goldwasser-Micali-Rackoff 1985).

Manuel Blum (1938–)

Pioneer in computational complexity. ACM Turing Award 1995. Co-supervised Goldwasser, Micali, Yao.

Andrew Yao (1946–)

ACM Turing Award 2000. Invented garbled circuits (1982) — basis of modern MPC. Yao's millionaires' problem.

Modern symmetric cryptography

Joan Daemen (1965–)

Belgian, Radboud Univ. Co-designer of Rijndael (AES) with Vincent Rijmen (1998). Co-designer of Keccak/SHA-3, conceptual ChaCha. Author of The Design of Rijndael. ACM Turing Award 2024 (shared with Rijmen).

Vincent Rijmen (1970–)

Belgian, KU Leuven. Co-designer of Rijndael (AES). Co-designer of the Whirlpool hash. ACM Turing Award 2024.

Eli Biham (1960–)

Israeli, Technion. Co-inventor of differential cryptanalysis (1990 with Shamir). Designer/cryptanalysis: Serpent (AES finalist), Tiger hash, Lucifer-Beth attack.

Mitsuru Matsui (1961–)

Mitsubishi. Invented linear cryptanalysis (1993) — breaks DES in 2^43.

Lars Knudsen (1962–)

Danish, DTU. Cryptanalysis on DES, AES, IDEA. Co-designer of Serpent (AES finalist).

Bruce Schneier (1963–)

Independent consultant. Designer of Blowfish (1993), Twofish (1998, AES finalist), Helix, Threefish. Author of Applied Cryptography, Cryptography Engineering, Secrets and Lies, Data and Goliath. Influential crypto-blogger. Researcher at the Berkman Klein Center, Harvard.

Niels Ferguson (1965–)

Dutch, Microsoft. Co-author of Twofish, Helix, Cryptography Engineering (with Schneier+Kohno). Designer of BitLocker encryption.

David Wagner (1968–)

Berkeley professor. Co-author of Twofish. Massive contributions to cryptanalysis (slide attack, related-key, fault attacks).

John Kelsey (1969–)

NIST cryptographer. Co-author of multiple AES finalists and hash designs.

Phil Zimmermann (1954–)

Created PGP (1991). The government attempted criminal prosecution under arms export law (1993–1996) — abandoned. Co-creator of Zfone. Founder of Silent Circle.

Daniel J. Bernstein and the modern school

Daniel J. Bernstein "DJB" (1971–)

Professor at Univ. of Illinois Chicago + Ruhr-Univ. Bochum. Designer:

  • Curve25519 (2006).
  • Ed25519, Ed448 (2011, RFC 8032).
  • ChaCha20 (2008), Salsa20 (2005).
  • Poly1305 (2005).
  • SipHash (2012, with Aumasson).
  • BLAKE/BLAKE2 contributor (Aumasson lead).
  • qmail, djbdns (90s).

Philosophy: constant-time, simple, no patents, easy correct implementation. Sued the NSA/State Dept over crypto export law in 1995 (Bernstein v. United States) — won. Co-founder of the PQ-Crystals team — NTRU Prime, sntrup761. Co-creator of Classic McEliece and part of the PQC drama.

Tanja Lange (1975–)

Professor at TU Eindhoven. Co-author with DJB of many papers (Curve25519 SafeCurves, etc.). Co-lead of Classic McEliece. Expert in lattices and elliptic curves.

Jean-Philippe Aumasson (1980–)

Swiss. Lead designer of BLAKE (SHA-3 finalist), BLAKE2/3, SipHash, Argon2 (PHC winner). Co-author of Serious Cryptography. Co-founder of Taurus (custodial crypto).

Hash, MAC, PHC

Hans Dobbertin (1952–2006)

German cryptographer. Found collisions in MD4 (1995), MD5 (1996). Co-designer of RIPEMD-160.

Wang Xiaoyun (1966–)

Tsinghua Univ. Broke MD5 (2004), SHA-1 (2005) — discoveries that marked the post-MD era. Multiple awards in China.

Yiqun Lisa Yin (1976–)

Co-author of Wang's attacks on MD5/SHA-1.

Marc Stevens (1981–)

CWI Amsterdam. MD5 chosen-prefix collision (2007–2008) — used in the Flame malware. Co-author of the SHAttered SHA-1 collision (2017) + SHA-1 Shambles (2020).

Mihir Bellare (1962–)

UCSD. Random Oracle Model (1993, with Rogaway). HMAC (1996), OAEP (1994), PSS. Provable security pioneer.

Phillip Rogaway (1962–)

UC Davis. ROM, OAEP, PSS, CMC, OCB (patent now free). Format-Preserving Encryption (FFX). Influential ethics writer in crypto.

Hugo Krawczyk (1953–)

IBM Research + Algorand. HMAC (1996, with Bellare-Canetti), HKDF (2010), Signal Protocol (Off-The-Record). RWC 2017 Levchin Prize.

Dan Boneh (1969–)

Stanford professor. Practical Identity-Based Encryption (2001 with Franklin). BLS signatures (2001). Functional encryption, FHE pioneer (post-Gentry). Co-author of A Graduate Course in Applied Cryptography (free book). Multiple students became leading cryptographers.

Craig Gentry (1972–)

Stanford PhD 2009 under Boneh — first Fully Homomorphic Encryption scheme. IBM Research, later co-founder cryptographer at Algorand. ACM dissertation award.

Post-Quantum

Oded Regev (1980–)

NYU. LWE problem (2005) — basis of KyberDilithiumSaber. Worst-case → average-case reductions. Gödel Prize 2018.

Vadim Lyubashevsky (1980?–)

IBM Research. Co-author of Dilithium, Kyber. Lyubashevsky-Peikert-Regev framework for lattice signatures.

Léo Ducas (1985?–)

CWI. Co-author of Dilithium, Kyber, FALCON. Lattice attacks expert.

Peter Schwabe (1981–)

Radboud + MPI-SP. Co-author of Kyber, Dilithium, SPHINCS+, Classic McEliece, NewHope. PQ-Crystals team.

Andreas Hülsing (1985?–)

Eindhoven. Co-author of SPHINCS+, XMSS. Hash-based signatures expert.

Lily Chen (NIST)

Led the NIST PQC process. NIST Project Lead.

Wouter Castryck + Thomas Decru (2022)

KU Leuven. Broke SIKE on a laptop in 1 hour (Jul 2022). Drama: SIKE was a NIST Round 4 candidate, eliminated dramatically.

Peter Shor (1959–)

Bell Labs → MIT. Shor's algorithm (1994) — polynomial factoring on a quantum computer. Crypto and theoretical implications. ACM Turing Award... pending; multiple other awards.

Lov Grover (1961–)

Bell Labs. Grover's algorithm (1996) — quadratic speedup for quantum search.

Blockchain / Bitcoin / Ethereum

Satoshi Nakamoto (pseudonym, 2008–2011)

Unknown identity. Bitcoin whitepaper (2008), initial code release (2009–2010). Approximately 1M BTC never moved. Various theories: Hal Finney, Nick Szabo, Adam Back (all deny being Satoshi). A permanent mystery.

Hal Finney (1956–2014)

Cypherpunk, cryptographer. Implemented reusable proof-of-work (RPOW, 2004). Received the first Bitcoin transfer from Satoshi (block 170, Jan 2009). Died of ALS in 2014.

Adam Back (1970–)

Cryptography PhD, founder of Blockstream. Inventor of Hashcash (1997) — cited by Satoshi. Argued by some to be Satoshi (denies).

Nick Szabo (~1964–)

Cypherpunk. Concept of Bit Gold (1998–2005), smart contracts (1994). Speculated to be Satoshi (denies).

Wei Dai (~1976–)

Cypherpunk. b-money (1998) — cited by Satoshi. Designer of the Crypto++ library.

Vitalik Buterin (1994–)

Russian-Canadian. Co-founder of Ethereum (whitepaper 2013, launch 2015). Driving force behind Ethereum 2.0 (PoS migration Aug 2022).

Gavin Wood (1980–)

UK. Co-founder of Ethereum, author of the Yellow Paper, designer of Solidity. Founder of Polkadot/Parity.

Pieter Wuille (1985–)

Belgian, Blockstream/Bitcoin Core. Co-author of major Bitcoin BIPs: Schnorr (BIP340), Taproot (BIP341), Tapscript (BIP342), Bech32 (BIP173). Designer of libsecp256k1.

Greg Maxwell (~1978–)

Co-founder of Blockstream. Designer of Confidential Transactions, Mimblewimble inspirations, MuSig.

Zooko Wilcox-O'Hearn (1974–)

Founder of Zcash (with Matt Green et al.). Designer of BLAKE2/BLAKE3 (with Aumasson, Neves). Pioneer of Tahoe-LAFS. Privacy-focused engineer.

Sean Bowe (1990?–)

Electric Coin Co. Co-designer of Sapling (Zcash), Halo (no trusted setup SNARK), Halo2.

Eli Ben-Sasson (~1976–)

StarkWare co-founder. Co-inventor of zk-STARKs. Cairo language designer.

Benedikt Bünz (~1990–)

Stanford → NYU. Bulletproofs (2018), Plonky2 contributor, supernova folding scheme. Hot researcher in scaling SNARKs.

Side-channel pioneers

Paul Kocher (1973–)

Stanford PhD. Timing attacks (1996), DPA (1998). Co-discoverer of Spectre / Meltdown (2018). Founder of Cryptography Research (acquired by Rambus).

Daniel Bleichenbacher (1964–)

ETH Zurich PhD, Bell Labs. Bleichenbacher 1998 attack on RSA PKCS#1 v1.5 — revived as ROBOT (2017). DSA timing attacks.

J. Alex Halderman (1981–)

Univ. of Michigan. Cold Boot Attack (2008). E-voting security research. ROCA team (2017). Stuxnet analysis.

Implementers and communicators

Theo de Raadt (1968–)

Founder of OpenBSD, OpenSSH. Defines a security-first development culture.

Werner Koch (1961–)

Created GnuPG (1997, free PGP equivalent). Volunteer maintainer for decades; financial struggles famously discussed in 2015 ("GnuPG maintainer running out of money").

Filippo Valsorda (~1995–)

Italian. Cloudflare → Google Go. age file encryption tool. Mozilla CT log. PQC migration advocate. Author of go-internals security analyses. Newsletter Cryptography Dispatches.

Matthew Green (~1973–)

Johns Hopkins professor. Cryptographer + public communicator. Designer/co-designer of Zcash. Blog: blog.cryptographyengineering.com.

Tim Bray, Jon Callas, Eric Rescorla

IETF crypto people. Callas was Apple's iMessage architect.

Edward Snowden and the post-2013 era

Edward Snowden (1983–)

NSA contractor → whistleblower (2013). Revelations:

  • BULLRUN (NSA crypto sabotage).
  • DualECDRBG confirmed backdoor.
  • Mass surveillance programs.
  • TAO catalog (hardware implants).

Catalyst for the migration to mass PGP, Signal, ubiquitous end-to-end encryption, and the PQC push. Refugee in Russia since 2013.

Moxie Marlinspike (1980–)

Founder of Open Whisper Systems → Signal Foundation. Designer of the Signal Protocol (X3DH + Double Ratchet, with Trevor Perrin). Stepped down as CEO in 2022.

Trevor Perrin

Co-designer of the Signal Protocol, Noise Protocol Framework (2015–). Author of RFC 8032 EdDSA.

Bruce Schneier (re-mention)

Influential post-Snowden voice on policy, surveillance, and security culture. Books Data and Goliath, Click Here to Kill Everybody.

Russians / Chinese / others

Nikita Borisov, Kazuhiko Minematsu, Mridul Nandi

Cryptographers from various nations contributing to ISO standards, NESSIE, the CAESAR competition.

Bart Preneel (1963–)

KU Leuven. NESSIE coordinator, ECRYPT. Hash function attacks, MAC analysis. President of IACR in the 2010s.

Lai Xuejia (1954–)

China/Switzerland. Co-designer of IDEA (1991, with James Massey).

James Massey (1934–2013)

ETH Zurich. Co-designer of IDEA. SAFER cipher family.

Kazumaro Aoki

NTT. Cryptanalysis of Camellia, MISTY, KASUMI.

Recent and emerging

Chiara Marcolla, Ileana Buhan, Stefano Tessaro

European cryptographers active in PQC, post-quantum security analysis.

Brent Waters (1976–)

Cornell → UT Austin. Functional encryption, attribute-based encryption pioneer.

Hovav Shacham (~1975–)

UCSD → UT Austin. Co-designer of BLS signatures. SiGreal scheme. Election security work.

Nicolas Courtois

UCL. Algebraic attacks. Bitcoin pseudocrypto critic.

Justin Drake (~1985?–)

Ethereum Foundation. Sharding, randomness beacon design.

By category (index)

Pre-Shannon

Al-Kindi, Alberti, Bellaso, Kerckhoffs, Vernam, Mauborgne, Hill, Friedman (both).

Breaking Enigma

Rejewski, Różycki, Zygalski, Turing, Welchman, Tutte, Flowers, Newman, Alexander.

Public-key founders

Diffie, Hellman, Merkle, Rivest, Shamir, Adleman, Ellis, Cocks, Williamson, ElGamal, Koblitz, Miller.

Provable security

Goldwasser, Micali, Rackoff, Bellare, Rogaway, Boneh, Krawczyk.

AES era

Daemen, Rijmen, Biham, Knudsen, Schneier, Ferguson, Wagner, Kelsey.

Hash attacks

Dobbertin, Wang Xiaoyun, Yin, Stevens.

DJB school

Bernstein, Lange, Aumasson.

Post-Quantum

Shor, Grover, Regev, Lyubashevsky, Ducas, Schwabe, Hülsing, Castryck, Decru.

Side-channel

Kocher, Bleichenbacher, Halderman.

Blockchain

Nakamoto, Finney, Back, Szabo, Buterin, Wood, Wuille, Maxwell, Wilcox-O'Hearn, Bowe, Ben-Sasson, Bünz.

Signal / modern protocols

Marlinspike, Perrin, Krawczyk.

Activists / communicators

Zimmermann, Schneier, Snowden, Marlinspike, Valsorda, Green.

Cross-reference

  • Algorithms by person: see 04-symmetric.md, 05-asymmetric.md, 06-hash-and-mac.md.
  • Events by person: see 01-timeline.md and 13-incidents.md.
  • Attacks by person: see 11-attacks.md.
  • PQC / blockchain contributions: 08-post-quantum.md, 10-cryptocurrency.md.