(Roughly) Daily

Posts Tagged ‘codes

“One of the most singular characteristics of the art of deciphering is the strong conviction possessed by every person, even moderately acquainted with it, that he is able to construct a cipher which nobody else can decipher.”*…

And yet, for centuries no one has succeeded. Now, as Erica Klarreich reports, cryptographers want to know which of five possible worlds we inhabit, which will reveal whether truly secure cryptography is even possible…

Many computer scientists focus on overcoming hard computational problems. But there’s one area of computer science in which hardness is an asset: cryptography, where you want hard obstacles between your adversaries and your secrets.

Unfortunately, we don’t know whether secure cryptography truly exists. Over millennia, people have created ciphers that seemed unbreakable right until they were broken. Today, our internet transactions and state secrets are guarded by encryption methods that seem secure but could conceivably fail at any moment.

To create a truly secure (and permanent) encryption method, we need a computational problem that’s hard enough to create a provably insurmountable barrier for adversaries. We know of many computational problems that seem hard, but maybe we just haven’t been clever enough to solve them. Or maybe some of them are hard, but their hardness isn’t of a kind that lends itself to secure encryption. Fundamentally, cryptographers wonder: Is there enough hardness in the universe to make cryptography possible?

In 1995, Russell Impagliazzo of the University of California, San Diego broke down the question of hardness into a set of sub-questions that computer scientists could tackle one piece at a time. To summarize the state of knowledge in this area, he described five possible worlds — fancifully named Algorithmica, Heuristica, Pessiland, Minicrypt and Cryptomania — with ascending levels of hardness and cryptographic possibility. Any of these could be the world we live in…

Explore each of them– and their implications for secure encryption– at “Which Computational Universe Do We Live In?” from @EricaKlarreich in @QuantaMagazine.

Charles Babbage

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As we contemplate codes, we might we might send communicative birthday greetings to a frequentlyfeatured hero of your correspondent, Claude Elwood Shannon; he was born on this date in 1916.  A mathematician, electrical engineer– and cryptographer– he is known as “the father of information theory.”  But he is also remembered for his contributions to digital circuit design theory and for his cryptanalysis work during World War II, both as a codebreaker and as a designer of secure communications systems.

220px-ClaudeShannon_MFO3807

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“It may be roundly asserted that human ingenuity cannot concoct a cipher which human ingenuity cannot resolve”*…

But sometimes it takes lots of ingenuity… and often, a great deal of time…

The United States National Security Agency—the country’s premier signals intelligence organization—recently declassified a Cold War-era document about code-breaking.

The 1977 book, written by cryptologist Lambros Callimahos, is the last in a trilogy called Military Cryptanalytics. It’s significant in the history of cryptography, as it explains how to break all types of codes, including military codes, or puzzles—which are created solely for the purpose of a challenge.

The first two parts of the trilogy were published publicly in the 1980s and covered solving well-known types of classical cipher. But in 1992, the US Justice Department claimed releasing the third book could harm national security by revealing the NSA’s “code-breaking prowess“. It was finally released in December last year. 

A key part of Callimahos’s book is a chapter titled Principles of Cryptodiagnosis, which describes a systematic three-step approach to solving a message encrypted using an unknown method… 

See how those three steps work at “Declassified Cold War code-breaking manual has lessons for solving ‘impossible’ puzzles.”

* Edgar Allan Poe

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As we ponder puzzles, we might send intelligent birthday greetings to Alfred Binet; he was born on this date in 1857. A psychologist, he invented the first practical IQ test, the Binet–Simon test (in response to a request from the French Ministry of Education to devise a method to identify students needing remedial help).

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“Secret codes resound. Doubts and intentions come to light.”*…

 

Music cryptography is a method in which the musical notes A through G are used to spell out words, abbreviations, or codes…

Early 17th- and 18th-century mathematicians and cryptologists such as John Wilkins and Philip Thicknesse argued that music cryptography was one of the most inscrutable ways of transporting secret messages. They claimed that music was perfect camouflage, because spies would never suspect music. When played, the music would sound so much like any other composition that musically trained listeners would be easily fooled, too. Thicknesse wrote in his 1772 book A Treatise on the Art of Deciphering, and of Writing in Cypher: With an Harmonic Alphabet, “for who that examined a suspected messenger would think an old song, without words, in which perhaps the messenger’s tobacco or snuff might be put, contained a secret he was to convey?” Written letters don’t have this advantage…

This music cipher was supposedly proposed by Michael Haydn (brother of Franz Josef Haydn). It appears in an appendix to a biography about Haydn by Werigand Rettensteiner published in 1808.

More musical mischief at “With Musical Cryptography, Composers Can Hide Messages in Their Melodies.”

* Wislawa Szymborska

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As we bury the lede, we might tip the plumed birthday bonnet to Rene Descartes, the French philosopher and mathematician who thought and therefore was.  He was born on this date in 1596.

Many contemporaries (perhaps most notably, Pascal) rejected his famous conclusion, the dualist separation of mind and body; more (Voltaire, et al.), since.  But Descartes’ emphasis on method and analysis, his disciplined integration of philosophy and physical science, his insistence on the importance of consciousness in epistemology, and perhaps most fundamentally, his the questioning of tradition and authority had a transformative– and lasting– effect on Western thought, and has earned him the “title” of Father of Modern Philosophy.

“In order to improve the mind, we ought less to learn than to contemplate.”
– Rene Descartes

Frans Hals’ portrait of Descartes, c. 1649

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Written by (Roughly) Daily

March 31, 2018 at 1:01 am

Coded references…

Readers will recall the role that Alan Turing and the team at Bletchley Park played in cracking the German Enigma code; some analysts and historians reckon that their work may have shortened World War Two by “not less than two years.”

That code was generated by– and thus cracking it turned on deconstructing and understanding– an Enigma Machine.

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Understandably, there were few such machines ever built.  And equally understandable, those that survive are extremely expensive collectables.  But readers need fear not!  Now, thanks to our friends at Instructables, one can convert a “Kid’s Game to an Enigma Machine“:

Step-by-step instructions at Instructables.

Readers might also want to visit Cabinet Magazine‘s wonderful “How to Make Anything Signify Anything,” a profile of American code breaker (and code maker) William Friedman:

By the time he retired from the National Security Agency in 1955, Friedman had served for more than thirty years as his government’s chief cryptographer, and—as leader of the team that broke the Japanese PURPLE code in World War II, co-inventor of the US Army’s best cipher machine, author of the papers that gave the field its mathematical foundations, and coiner of the very term cryptanalysis—he had arguably become the most important code-breaker in modern history.

As we reach for our decoder rings, we might recall that it was on this date in 1884 that the states of Alabama, Georgia, Illinois, Indiana, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee and Virginia, with (at least) 50 tornadoes.  Known as “The Enigma Outbreak,” it did an estimated a total of $3–4 million in tornado damage (in 1884 dollars; plus an unknown amount of flood and other damage), destroying over 10,000 structures.

Photo: © D. Burgess / NOAA (source)

 

 

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