– 1900 BC Egyptian coding first recorded, followed by the Greeks scrambling, Romans Caesar moved each letter of the alphabet 3 spaces to the right

– 500 AD Roman Empires collapses and Arab societies keep the study of code alive, and were the first to record transposition and substitution, first to outline techniques of frequency analysis, i.e. counting the number of times a letter or word appears as a first step to noticing the most frequent letters

– 1466 Alberti, urged by the Vatican, creates a rotating cipher with discs, random, so disrupted frequency analysis as letter and number combinations changed, what is called poly alphabetic substitution

– 1586 French diplomat built a system with 26 alphabets

– 1586 also Mary Queen of Scot’s messages were decrypted by Walsingham

– 1700 Black chambers were throughout Europe

– 1844 Morse code invented, messages were public across Marconi’s radio waves, radio totally revolutionised communications, no wires, this stimulated a lot more codes and ciphers to encrypt

– one of the first things done when the WWI started was the cutting of the German cables – forcing them to use radio, all of the messages were sent straight to Room 40.

– September 1914 – the capture of the Magdeburg transformed modern combat because it delivered the German codebook

– 17 January 1917, using the codebook, Britain decrypted a telegram from the German FM Zimmerman to the German Ambassador in DC with a message to be sent on to the Mexican PM.  The DC German mission got it in a new code and decrypted it and re-encrypted it using the old code book to send on to Mexico.  THis is how the British worked it out. Zimmerman’s message broke US neutrality in the war.  Germany signaled its intent on 1 Feb to reengage in submarine warfare.  The proposal to Mexico was it invade the US and take back Texas, Arizona and to persuade Japan to attack the US.

– Scherbius – created enigma by mid-1920s, in the next 2 decades, 30,000 sold to german military

– Poles had world leading cryptanalyst bureau, even reconstructed a rewiring of enigma machines, Rejewski was an extraordinary mathematics skills – he called his machine the bombe because of the sound it made when it went through its permutations

– 1931 Hans Schmidt provided intel on Enigma but not on how the keyboard wired up to the rotor

– The Germans daily changed the key – it was distributed in a monthly code book

– Tommy Flowers created Colossus

– William Friedman headed US signals corps and helped solve the Japanese code, Purple

– Feb 1938 the purple machine introduced several rotors, but human error helped it being broken, the same message was sent in red and purple codes, i.e. the old and the new

– Leo Rosen built a machine to decipher purple which it had by 1940

– D Day invasion, informed by incredibly detailed report by Japan’s ambassador of German war capabilities and assets

– Japanese code decrypted ordering huge invasion at AF.  Was it Midway? A message was sent out saying that Midway was short of water, and sure enough, the Japanese confirmed this.  On 4 June the attack on Midway started and hovering off their flank was a surprise attack, that sank four Japanese aircraft carriers – this was a turning point in the Pacific War.

– Johnston proposed Navaho be used in communications, the Marines trained up 29 Navahos, and by August 1942 Navaho code breakers saw action in Guadalcanal, by the end of the war 420 code talkers using radio radio in native languages to communicate instantly. In 1968 it became public and in 1982 honours were given.

– distributing keys is the problem in modern computer codes – Diffy Helman Merkle created public key encryption, public and private keys that were different but related, they created RSA, the first company to market crypto, the NSA tried to stop it

– 1986 stopped Lotus notes exporting software because RSA encryption included

– 1993 investigated Zimmerman for PGP because RSA encryption used over the internet, ending the NSA’s monopoly, now academic encryption had reached parity with the NSA

– 1994 RSA encryption in most software

– 1993 Clipper chip proposal from the NSA to be installed in telephones to decrypt voice – by 1996 dropped

– 1996 MIT published PGP in a book and on its site