Feeds

Turing's rapid Nazi Enigma code-breaking secret revealed

Maths homework kept in GCHQ vault for 70 years

Intelligent flash storage arrays

Blighty's communications eavesdropping nerve centre GCHQ has issued two papers written by superboffin Alan Turing on the maths behind code-breaking.

The documents, held in secret for 70 years, laid the foundations for the quick and efficient decryption of Nazi Enigma-scrambled messages - a breakthrough that lopped about two years off the duration of the Second World War.

The papers were donated on Friday to The National Archive in Kew, Surrey, where they will be available to view on request. An archives spokesperson said demand to see Turing's work is high, but there is no plan to put it online.

The GCHQ mathematician who handed over the documents, named only as Richard, told the BBC that the agency had now "squeezed the juice" out of the two papers and was "happy for them to be released into the public domain". The move coincides with the 100th anniversary of Turing's birth on 23 June this year.

The two typewritten papers feature Turing's hand-scribbled notes, and are titled On Statistics of Repetitions and The Applications of Probability to Cryptography.

Excerpt from Turing paper, credit: National Archive scan

Turing the tables on Nazi encryption - click for the full page

The statistics paper describes how examining repeated characters in two encrypted messages can prove that both passages use the same encipherment key. The cryptography essay is longer and applies rigorous probability analysis to code-breaking methods and techniques.

The mathematical workings are given a little historical piquancy when Turing uses life expectancy to examine conditional probability, taking Hitler - then aged 52 - as an example. It dates the paper to between April 1941 and April 1942.

According to GCHQ's Richard, the papers used "mathematical analysis to try and determine the more likely settings [for the crypto key] so that they can be tried as quickly as possible".

The agency added that the message decryption rate achieved by wartime code-breakers at Bletchley Park was "almost certainly enabled by the techniques in this paper". More details on Turing's newly revealed work can be found here. ®

Internet Security Threat Report 2014

More from The Register

next story
MI6 oversight report on Lee Rigby murder: US web giants offer 'safe haven for TERRORISM'
PM urged to 'prioritise issue' after Facebook hindsight find
Assange™ slumps back on Ecuador's sofa after detention appeal binned
Swedish court rules there's 'great risk' WikiLeaker will dodge prosecution
NSA mass spying reform KILLED by US Senators
Democrats needed just TWO more votes to keep alive bill reining in some surveillance
'Internet Freedom Panel' to keep web overlord ICANN out of Russian hands – new proposal
Come back with our internet! cries Republican drawing up bill
What a Mesa: Apple vows to re-use titsup GT sapphire glass plant
Commits to American manufacturing ... of secret tech
prev story

Whitepapers

Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Designing and building an open ITOA architecture
Learn about a new IT data taxonomy defined by the four data sources of IT visibility: wire, machine, agent, and synthetic data sets.
10 threats to successful enterprise endpoint backup
10 threats to a successful backup including issues with BYOD, slow backups and ineffective security.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.