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1466 BCE
Polyalphabetic Cipher
Leon Battista ALberti invents polyalphabetic cipher. -
Period: 801 BCE to 873 BCE
Monoalphabetic Substitution Ciphers
Cryptanalysis and frequency analysis leading to techniques for breaking monoalphabetic substitution ciphers are developed in a manuscript on Deciphering Cryptographic Messages by the Muslim mathematician, Al-Kindi, who was said to be inspired by the textual analysis of the Qur''an. He also covers methods of encipherments, cryptanalysis of certain encipherments, and statistical analysis of letters and letter combinations in Arabic. -
400 BCE
Herodotus reports the use of stenography.
Reports of stenography in reports to Greece from Persia, Such as tattoo on a shaved head. -
Period: Dec 14, 1355 to Dec 15, 1418
Ahmad al-Qalqashandi Writes a Encyclopedia Set with Cryptology Volume
Ahmad al-Qalqashandi (1355–1418) wrote the Subh al-a 'sha, a 14-volume encyclopedia which included a section on cryptology. This information was attributed to Ibn al-Durayhim who lived from 1312 to 1361, but whose writings on cryptography have been lost. The list of ciphers in this work included both substitution and transposition, and for the first time, a cipher with multiple substitutions for each plaintext letter. -
Period: to
Samuel Morse Develops Morse Code
Morse conceived of the idea of the single-circuit, electro-magnetic telegraph in 1832. With some assistance from Leonard Gale, a university science professor, Morse spent the next five years developing his ideas into a working model. This included the use of a code of dots and dashes for the letters of the alphabet, which became known as the Morse Code. The dots and dashes were transmitted as short and long electrical impulses with gaps in between. -
Period: to
Scovell Break Napoleon's code
George Scovell was chief codebreaker for the Duke of Wellington. During the Peninsular War of 1808-1814 he developed a system of military communications and intelligence gathering for the British that intercepted French letters and dispatches to and from the battlefield, and cracked their codes, eventually breaking Napoleons code. -
Period: to
Charles Wheatstone Invents Playfair Cipher
The Playfair cipher, 1854 by Charles Wheatstone, which encrypts pairs of letters (digraphs), instead of single letters as in the simple substitution cipher. The Playfair is significantly harder to break since the frequency analysis used for simple substitution ciphers does not work with it. Frequency analysis can still be undertaken, but on the 25*25=625 possible digraphs rather than the 25 possible monographs. Frequency analysis thus requires much more ciphertext in order to work. -
WW2 Japanese Navy Cryptography
Shortly after the Japanese attacked Pearl Harbor, bringing the United States into war with the Empire, they controlled the Pacific with a very dominant and overwhelming armada. The United States was not prepared to fight a sea war in the Pacific and had to scramble. During one of the most pivital battles of the Pacific war, the United States Navy was able to intercept Japanese orders to it's fleet and decrypt them. Many believe this turned the tide of the war. -
Period: to
Jefferson Disk Cipher
The Jefferson disk is also known as the Jefferson Wheel Cipher or the Bazeries Cylinder. It was invented in 1795 by the third US president, Thomas Jefferson, but became widely known after it was re-invented by Commandant Etienne Bazeries about a century later [1]. The Jefferson disk was later refined to the M-94 that was used by the United States Army between 1923 and 1942. -
The Data Encryption Standard
The Data Encryption Standard (DES) is a symmetric-key block cipher published by the National Institute of Standards and Technology (NIST).
The National Institute of Standards wanted to come up with an industry wide standard of encryption that could be used by all US agencies. They called this standard the Data Encryption Standard and it would stay that way until AES was created. -
Diffie-Hellman key exchange
Diffie-Hellman key exchange, also called exponential key exchange, is a method of digital encryption that uses numbers raised to specific powers to produce decryption keys on the basis of components that are never directly transmitted, making the task of a would-be code breaker mathematically overwhelming. -
Pretty Good Privacy
Created by Phil Zimmermann, PGP (Pretty Good Privacy), is a state-of-the-art cryptography system. It is a very widely used program that encrypts and decrypt emails over the Internet. It can also authenticate messages with digital signatures. -
Advanced Encryption Standard
AES or Advanced Encryption Standards was a new method of cryptography that utilizes an encryption algorithm created by two Belgian Cryptographers, Joan Daemen and Vincent Rijmen. It specifically increased the block size of key lengths from older methods like DES. This allowed for a high increase in secure encryption that is still used today. -
WEP Cracking
t a recent ISSA (Information Systems Security Association) meeting in Los Angeles, a team of FBI agents demonstrated current WEP-cracking techniques and broke a 128 bit WEP key in about three minutes. Special Agent Geoff Bickers ran the Powerpoint presentation and explained the attack, while the other agents (who did not want to be named or photographed) did the dirty work of sniffing wireless traffic and breaking the WEP keys. -
NIST suggests that 80-bit keys for symmetric key cyphers be phased out
As of 2015, NIST guidance says that "the use of keys that provide less than 112 bits of security strength for key agreement is now disallowed." NIST approved symmetric encryption algorithms include three-key Triple DES, and AES. Approvals for two-key Triple DES and Skipjack have been withdrawn as of 2015. NIST key management guidelines further suggest that 15360-bit RSA keys are equivalent in strength to 256-bit symmetric keys.