(Roughly) Daily

Posts Tagged ‘codes

“There are two types of encryption: one that will prevent your sister from reading your diary and one that will prevent your government”*…

… But sometimes the encryption you think will work against governments won’t even deter your sister. Joesph Cox on the recently-uncovered vulnerabilities in TETRA, the encryption standard used in radios worldwide…

A group of cybersecurity researchers has uncovered what they believe is an intentional backdoor in encrypted radios used by police, military, and critical infrastructure entities around the world. The backdoor may have existed for decades, potentially exposing a wealth of sensitive information transmitted across them, according to the researchers… The end result, however, are radios with traffic that can be decrypted using consumer hardware like an ordinary laptop in under a minute…

The research is the first public and in-depth analysis of the TErrestrial Trunked RAdio (TETRA) standard in the more than 20 years the standard has existed. Not all users of TETRA-powered radios use the specific encryption algorithim called TEA1 which is impacted by the backdoor. TEA1 is part of the TETRA standard approved for export to other countries. But the researchers also found other, multiple vulnerabilities across TETRA that could allow historical decryption of communications and deanonymization. TETRA-radio users in general include national police forces and emergency services in Europe; military organizations in Africa; and train operators in North America and critical infrastructure providers elsewhere. 

Midnight Blue [presented] their findings at the Black Hat cybersecurity conference in August. The details of the talk have been closely under wraps, with the Black Hat website simply describing the briefing as a “Redacted Telecom Talk.” That reason for secrecy was in large part due to the unusually long disclosure process. Wetzels told Motherboard the team has been disclosing these vulnerabilities to impacted parties so they can be fixed for more than a year and a half. That included an initial meeting with Dutch police in January 2022, a meeting with the intelligence community later that month, and then the main bulk of providing information and mitigations being distributed to stakeholders. NLnet Foundation, an organization which funds “those with ideas to fix the internet,” financed the research.

The European Telecommunications Standards Institute (ETSI), an organization that standardizes technologies across the industry, first created TETRA in 1995. Since then, TETRA has been used in products, including radios, sold by Motorola, Airbus, and more. Crucially, TETRA is not open-source. Instead, it relies on what the researchers describe in their presentation slides as “secret, proprietary cryptography,” meaning it is typically difficult for outside experts to verify how secure the standard really is.

Bart Jacobs, a professor of security, privacy and identity, who did not work on the research itself but says he was briefed on it, said he hopes “this really is the end of closed, proprietary crypto, not based on open, publicly scrutinised standards.”…

The veil, pierced: “Researchers Find ‘Backdoor’ in Encrypted Police and Military Radios,” from @josephfcox in @motherboard. (Not long after this article ran– and after the downfall of Vice, Motherboard’s parent), Cox and a number of his talented Motherboard colleagues launched 404 Media. Check it out.)

Remarkably, some of the radio systems enabling critical infrastructure are even easier to hack– they aren’t even encrypted.

Bruce Schneier (@schneierblog)

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As we take precautions, we might recall that it was on this date in 1980 that the last IBM 7030 “Stretch” mainframe in active use is decommissioned at Brigham Young University. The first Stretch was was delivered to Los Alamos National Laboratory in 1961, giving the model almost 20 years of operational service.

The Stretch was famous for many things, but perhaps most notably it was the first IBM computer to use transistors instead of vacuum tubes; it was the first computer to be designed with the help of an earlier computer; and it was the world’s fastest computer from 1961 to 1964.

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“The sciences of cryptography and mathematics are very elegant, pure sciences. I found that the ends for which these pure sciences are used are less elegant.”*…

Mary, Queen of Scots wrote 57 encrypted messages during her captivity in England; until recently, all but 7 of them were believed lost. Meilan Solly tells the tale of their discovery and decryption…

Over the course of her 19 years in captivity, Mary, Queen of Scots, wrote thousands of letters to ambassadors, government officials, fellow monarchs and conspirators alike. Most of these missives had the same underlying goal: securing the deposed Scottish queen’s freedom. After losing her throne in 1567, Mary had fled to England, hoping to find refuge at her cousin Elizabeth I’s court. (Mary’s paternal grandmother, Margaret Tudor, was the sister of Elizabeth’s father, Henry VIII.) Instead, the English queen imprisoned Mary, keeping her under house arrest for nearly two decades before ordering her execution in 1587.

Mary’s letters have long fascinated scholars and the public, providing a glimpse into her relentless efforts to secure her release. But the former queen’s correspondence often raises more questions than it answers, in part because Mary took extensive steps to hide her messages from the prying eyes of Elizabeth’s spies. In addition to folding the pages with a technique known as letterlocking, she employed ciphers and codes of varying complexity.

More than 400 years after Mary’s death, a chance discovery by a trio of code breakers is offering new insights into the queen’s final years. As the researchers write in the journal Cryptologia, they originally decided to examine a cache of coded notes housed at the National Library of France as part of a broader push to “locate, digitize, transcribe, decipher and analyze” historic ciphers. Those pages turned out to be 57 of Mary’s encrypted letters, the majority of which were sent to Michel de Castelnau, the French ambassador to England, between 1578 and 1584. All but seven were previously thought to be lost…

What they found and how they made sense of it: “Code Breakers Discover—and Decipher—Long-Lost Letters by Mary, Queen of Scots,” from @meilansolly in @SmithsonianMag.

Jim Sanborn, the sculptor who created the encrypted Kryptos sculpture at CIA headquarters

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As we crack codes, we might spare a thought for a rough contemporary of Mary’s, a man who refused to communicate in code: Giordano Bruno. A Dominican friar, philosopher, mathematician, and astronomer whose concept of the infinite universe expanded on Copernicus’s model, he was the first European to understand the universe as a continuum where the stars we see at night are identical in nature to the Sun.  Bruno’s views were considered dangerously heretical by the (Roman) Inquisition, which imprisoned him in 1592; after eight years of refusals to recant, on this date in 1600, he was burned at the stake.

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Written by (Roughly) Daily

February 17, 2023 at 1:00 am

“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