A code chronology

Date

Event

c. 1900 BC

Some Egyptian hieroglyphs are written in non-standard characters, a code apparently intended to add a little mystery. Possibly as little as 250 years later a small part of the Leiden, or Ipuwer, papyrus (dates much disputed) was partly in cipher

c. 1500 BC

A Sumerian pottery glaze recipe is written in code

600–500 BC

Hebrew scribes use the ATBASH cipher

487 BC

Greek use of the scytale device is recorded

60–50 BC

Julius Caesar’s shift cipher is used

AD 0–400 (date unknown)

The Kama Sutra of Vatsayana lists cryptography as the 44th and 45th of 64 arts (yogas) for men and women

805–873

Lifespan of Abu Al-Kindi, the first genuine cryptanalyst

c. 1214–94

Lifespan of Roger Bacon (Dr Mirabilis), who described ciphers in use

1379

Gabrieli di Lavinde publishes the first-known nomenclators

1391

Treatise on the Astrolabe, attributed to English poet Geoffrey Chaucer, contains some enciphered passages

1412

Subh al-a‘sha, a 14-volume encyclopedia written by Shihab al-Din al-Qalqashand, includes material on cryptology

1466–7

Leon Battista Alberti invents the cipher disc to allow encryption using two alphabets

16th century

Religious disputes make secret communication more important, stimulating the use of nomenclators and ciphers and the growth of the deciphering ‘black chambers’

1516

First printed book on cryptology, Steganographia by Johannes Trithemius, is published

1563

Giovanni Battista Porta creates the first-known polygraphic substitution cipher

1586

Blaise de Vigenère publishes his Vigenère square

1587

Mary, Queen of Scots is executed after her codes are broken

17th century

Antoine and Bonaventure Rossignol develop the Great Cipher (date of creation unknown)

1623

Francis Bacon produces his bilateral code

1781

Benjamin Franklin invents the homophonic substitution cipher

1790s

Thomas Jefferson invents the Jefferson wheel, then forgets about it

1791

Optical telegraph is demonstrated

1811

Major George Scovell cracks the French codes, helping Wellington win the Peninsular War

1838

Morse code is invented

1844

Invention of the electric telegraph stimulates new interest in code making

1854

Playfair cipher is invented by Charles Wheatstone

1891

Bazières cylinder develops as a reinvention of the Jefferson wheel

1914–18

World War I encourages the development and use of ciphers, field codes and cryptanalysis

1914

Code-breaking Room 40 is set up at Admiralty House, London

1917

US enters the war as a result of the deciphered Zimmerman telegram

1918

Gilbert S. Vernam and Joseph Mauborgne devise the Vernam cipher one-time pad

1924

Enigma machine first shown

1939–45

Codes and ciphers play an important role in concealing and revealing communications during World War II

1974

Story of how Enigma had been solved is told

1976

Diffie–Hellman–Merkle key exchange scheme introduces the idea of public key encryption

1977

RSA algorithm makes public key encryption feasible

1990s

The rapid global rise of the internet and email communication highlights the issue of digital cryptography

1990

First research is published on quantum cryptography

1991

Phil Zimmerman releases his Pretty Good Privacy program