Posts Tagged ‘cryptography’
“Whoever wishes to keep a secret must hide the fact that he possesses one”*…
… or, as Sheon Han explains, maybe not…
Imagine you had some useful knowledge — maybe a secret recipe, or the key to a cipher. Could you prove to a friend that you had that knowledge, without revealing anything about it? Computer scientists proved over 30 years ago that you could, if you used what’s called a zero-knowledge proof.
For a simple way to understand this idea, let’s suppose you want to show your friend that you know how to get through a maze, without divulging any details about the path. You could simply traverse the maze within a time limit, while your friend was forbidden from watching. (The time limit is necessary because given enough time, anyone can eventually find their way out through trial and error.) Your friend would know you could do it, but they wouldn’t know how.
Zero-knowledge proofs are helpful to cryptographers, who work with secret information, but also to researchers of computational complexity, which deals with classifying the difficulty of different problems. “A lot of modern cryptography relies on complexity assumptions — on the assumption that certain problems are hard to solve, so there has always been some connections between the two worlds,” said Claude Crépeau, a computer scientist at McGill University. “But [these] proofs have created a whole world of connection.”…
More about how zero-knowledge proofs allow researchers conclusively to demonstrate their knowledge without divulging the knowledge itself: “How Do You Prove a Secret?,” from @sheonhan in @QuantaMagazine.
* Johann Wolfgang von Goethe
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As we stay sub rosa, we might recall that today (All Saints Day) is the (fictional) birthday of Hello Kitty (full name: Kitty White); she was born in a suburb of London. A cartoon character designed by Yuko Shimizu (currently designed by Yuko Yamaguchi), she is the property of the Japanese company Sanrio. An avatar of kawaii (cute) culture, Hello Kitty is one of the highest-grossing media franchises of all time; Hello Kitty product sales and media licensing fees have run as high as $8 billion a year.
“If you are confused by the underlying principles of quantum technology – you get it!”*…
A tour through the map above– a helpful primer on the origins, development, and possible futures of quantum computing…
From Dominic Walliman (@DominicWalliman) on @DomainOfScience.
* Kevin Coleman
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As we embrace uncertainty, we might spare a thought for
Alan Turing; he died on this date in 1954. A British mathematician, he was a foundational computer science pioneer (inventor of the Turing Machine, creator of the “Turing Test” (perhaps to b made more relevant by quantum computing :), and inspiration for “The Turing Award“) and cryptographer (leading member of the team that cracked the Enigma code during WWII).
“There’s no idea in economics more beautiful than Arrow’s impossibility theorem”*…
Tim Harford unpack’s Kenneth Arrow‘s Impossibility Theorem (which feels a bit like a socio-economic “Monty Hall Problem“) and considers it’s implications…
… if any group of voters gets to decide one thing, that group gets to decide everything, and we prove that any group of decisive voters can be pared down until there’s only one person in it. That person is the dictator. Our perfect constitution is in tatters.
That’s Arrow’s impossibility theorem. But what does it really tell us? One lesson is to abandon the search for a perfect voting system. Another is to question his requirements for a good constitution, and to look for alternatives. For example, we could have a system that allows people to register the strength of their feeling. What about the person who has a mild preference for profiteroles over ice cream but who loathes cheese? In Arrow’s constitution there’s no room for strong or weak desires, only for a ranking of outcomes. Maybe that’s the problem.
Arrow’s impossibility theorem is usually described as being about the flaws in voting systems. But there’s a deeper lesson under its surface. Voting systems are supposed to reveal what societies really want. But can a society really want anything coherent at all? Arrow’s theorem drives a stake through the heart of the very idea. People might have coherent preferences, but societies cannot…
On choice, law, and the paradox at the heart of voting: “Arrow’s Impossibility Theorem,” from @TimHarford in @WhyInteresting. Eminently worth reading in full.
* Tim Harford
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As we contemplate collective choice, we might send grateful birthday greetings to the man who “wrote the book” on perspective, Leon Battista Alberti; he was born on this date in 1404. The archetypical Renaissance humanist polymath, Alberti was an author, artist, architect, poet, priest, linguist, philosopher, cartographer, and cryptographer. He collaborated with Toscanelli on the maps used by Columbus on his first voyage, and he published the the first book on cryptography that contained a frequency table.
But he is surely best remembered as the author of the first general treatise– Della Pictura (1434)– on the the laws of perspective, which built on and extended Brunelleschi’s work to describe the approach and technique that established the science of projective geometry… and fueled the progress of painting, sculpture, and architecture from the Greek- and Arabic-influenced formalism of the High Middle Ages to the more naturalistic (and Latinate) styles of Renaissance.
“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.”
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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
“The most fruitful and natural exercise for our minds is, in my opinion, conversation”*…
In this age of Alexa and Siri, it’s worth recalling the (long) history of human-machine conversation. At MIT in 1966 an experiment with an early form of artificial intelligence anticipated just how close we might grow with our machines…
Client: Men are all alike.
ELIZA (a computer): In what way
Client: They’re always bugging us about something or other.
ELIZA: Can you think of a specific example
Client: Well, my boyfriend made me come here.
ELIZA: Your boyfriend made you come here
Client: He says I’m depressed much of the time.
ELIZA: I am sorry to hear you are depressed
Client: It’s true. I am unhappy.
ELIZA: Do you think coming here will help you not to be unhappy
Client: I need some help, that much seems certain.
– Joseph Weizenbaum, from a transcription of “Computational Linguistics.”
Named after George Bernard Shaw’s ingénue in Pygmalion, the ELIZA program operated on the Project MAC computer system at MIT and made natural language exchange possible between man and machine. ELIZA identified key words and phrases and responded with rote answers that simulated a conversation.
“Talking Cure,” via Lapham’s Quarterly.
* Michel de Montaigne, The Essays
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As we lie back on the couch, we might note that it was on this date in 1928 that the Enigma Machine encoded its first message.
A simple German machine the size of a portable typewriter, ENIGMA allowed for security in communications by a process in which typed letters were replaced by a cipher text displayed on illuminated lamps. The cipher was symmetrical so entering the cipher text into another ENIGMA reproduced the original message. Security was provided by a set of rotor wheels and a series of patch cables whose arrangement was agreed upon previously.
ENIGMA was used extensively by the German military during World War II to transmit battle plans and other secret information. By December of 1941, however, British codebreakers managed to decipher the code, allowing them to routinely read most ENIGMA traffic.
[source- Computer History Museum]
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