Cryptography Quotes

here’s a toast to Alan Turing born in harsher, darker times who thought outside the container and loved outside the lines and so the code-breaker was broken and we’re sorry yes now the s-word has been spoken the official conscience woken – very carefully scripted but at least it’s not encrypted – and the story does suggest a part 2 to the Turing Test: 1. can machines behave like humans? 2. can we?

One must acknowledge with cryptography no amount of violence will ever solve a math problem.

When we pair modern tech like Blockchain technology, cryptography and data analytics with the ancient practice of bartering, a lot of business opportunities emerge.

Computers had their origin in military cryptography—in a sense, every computer game represents the commandeering of a military code-breaking apparatus for purposes of human expression.

-How long do you want these messages to remain secret?[...] +I want them to remain secret for as long as men are capable of evil.

Cryptographic tokens can be used as tools of stigmergy to incentivize good behavior and decentivize bad behavior in the context of business systems.

Adaptive collective action is superior to bureaucracy.

Imagine a young Isaac Newton time-travelling from 1670s England to teach Harvard undergrads in 2017. After the time-jump, Newton still has an obsessive, paranoid personality, with Asperger’s syndrome, a bad stutter, unstable moods, and episodes of psychotic mania and depression. But now he’s subject to Harvard’s speech codes that prohibit any “disrespect for the dignity of others”; any violations will get him in trouble with Harvard’s Inquisition (the ‘Office for Equity, Diversity, and Inclusion’). Newton also wants to publish Philosophiæ Naturalis Principia Mathematica, to explain the laws of motion governing the universe. But his literary agent explains that he can’t get a decent book deal until Newton builds his ‘author platform’ to include at least 20k Twitter followers – without provoking any backlash for airing his eccentric views on ancient Greek alchemy, Biblical cryptography, fiat currency, Jewish mysticism, or how to predict the exact date of the Apocalypse. Newton wouldn’t last long as a ‘public intellectual’ in modern American culture. Sooner or later, he would say ‘offensive’ things that get reported to Harvard and that get picked up by mainstream media as moral-outrage clickbait. His eccentric, ornery awkwardness would lead to swift expulsion from academia, social media, and publishing. Result? On the upside, he’d drive some traffic through Huffpost, Buzzfeed, and Jezebel, and people would have a fresh controversy to virtue-signal about on Facebook. On the downside, we wouldn’t have Newton’s Laws of Motion.

Encryption works. Properly implemented strong crypto systems are one of the few things that you can rely on. Unfortunately, endpoint security is so terrifically weak that NSA can frequently find ways around it.

This has serveral consequences, starting with screwing over most cryptography algorithms--translation: all your bank account are belong to us--

The value we provide at Mayflower-Plymouth exists at the convergence of various technologies and studies including Blockchain, cryptography, quantum computing, permaculture design principles, artificial intelligence, stigmergy, forestry, economics, additive manufacturing, big data, advanced logistics and more.

He stopped, because he wasn’t sure what Cryptography had established, and because he needed another moment to haul himself down from the ledges of her high cheekbones, to retreat from the caves of her eyes.

The enemy knows the system

The value we provide at Mayflower exists at the convergence of various new technologies and studies including Blockchain, cryptography, quantum computing, artificial intelligence, stigmergy, additive manufacturing, big data, advanced logistics and more.

It's not about Bitcoin or Ethereum or NFT's... These things have merely shown us what's possible. But the real value is in Cryptography, Blockchain Technology, Cryptocurrency and Smart Contracts - these are the things with the real business implications.

if a message protected by quantum cryptography were ever to be deciphered, it would mean that quantum theory is flawed,

The world is not sliding, but galloping into a new transnational dystopia. This development has not been properly recognized outside of national security circles. It has been hidden by secrecy, complexity and scale. The internet, our greatest tool of emancipation, has been transformed into the most dangerous facilitator of totalitarianism we have ever seen. The internet is a threat to human civilization. These transformations have come about silently, because those who know what is going on work in the global surveillance industry and have no incentives to speak out. Left to its own trajectory, within a few years, global civilization will be a postmodern surveillance dystopia, from which escape for all but the most skilled individuals will be impossible. In fact, we may already be there. While many writers have considered what the internet means for global civilization, they are wrong. They are wrong because they do not have the sense of perspective that direct experience brings. They are wrong because they have never met the enemy.

if N is large enough, it is virtually impossible to deduce p and q from N, and this is perhaps the most beautiful and elegant aspect of the RSA asymmetric cipher.

Modern technologies are 99 percent bravery , and 1 percent investment

Understanding block-chain makes you go mad, unless you start your own cult

Even though we don't know which companies the NSA has compromised – or by what means – knowing that they could have compromised any of them is enough to make us mistrustful of all of them. This is going to make it hard for large companies like Google and Microsoft to get back the trust they lost. Even if they succeed in limiting government surveillance. Even if they succeed in improving their own internal security. The best they'll be able to say is: "We have secured ourselves from the NSA, except for the parts that we either don't know about or can't talk about.

While I pray that public awareness and debate will lead to reform, bear in mind that the policies of men change in time, and even the Constitution is subverted when the appetites of power demand it. In words from history: Let us speak no more of faith in man, but bind him down from mischief by the chains of cryptography. I instantly recognized the last sentence as a play on a Thomas Jefferson quote from 1798 that I often cited in my writing: “In questions of power, then, let no more be heard of confidence in man, but bind him down from mischief by the chains of the Constitution.

the enemy of security: repetition leads to patterns, and cryptanalysts thrive on patterns.

An immortal instinct deep within the spirit of man is thus plainly a sense of the Beautiful.

The NSA employs more mathematicians, buys more computer hardware, and intercepts more messages than any other organization in the world.

Gideon was lolling behind Harrow, picking at her fingernails and staring at the pieces of paper, which had handwriting that was more like cryptography.

Bitcoin’s cryptography is solid, but it’s a bit like putting a six inch thick steel vault door in a cardboard frame.

Some days I spent up to three hours in the arcade after school, dimly aware that we were the first people, ever, to be doing these things. We were feeling something they never had - a physical link into the world of the fictional - through the skeletal muscles of the arm to the joystick to the tiny person on the screen, a person in an imagined world. It was crude but real. We'd fashioned an outpost in the hostile, inaccessible world of the imagination, like dangling a bathysphere into the crushing dark of the deep ocean, a realm hitherto inaccessible to humankind. This is what games had become. Computers had their origin in military cryptography - in a sense, every computer game represents the commandeering of a military code-breaking apparatus for purposes of human expression. We'd done that, taken that idea and turned it into a thing its creators never imagined, our own incandescent mythology.

The tactic seemed to work, so he stuck to the same theme for the next few days, but there was only so much cryptography he could teach before it started squeezing out everything else.

For much of history since its beginning in ancient Egypt, the essence of cryptography—which takes its name from the Greek words for “hidden” and “writing”—lay in encoding language to keep a message secret.

Ron Rivest, one of the inventors of RSA, thinks that restricting cryptography would be foolhardy: It is poor policy to clamp down indiscriminately on a technology just because some criminals might be able to use it to their advantage. For example, any U.S. citizen can freely buy a pair of gloves, even though a burglar might use them to ransack a house without leaving fingerprints. Cryptography is a data-protection technology, just as gloves are a hand-protection technology. Cryptography protects data from hackers, corporate spies, and con artists, whereas gloves protect hands from cuts, scrapes, heat, cold, and infection. The former can frustrate FBI wiretapping, and the latter can thwart FBI fingerprint analysis. Cryptography and gloves are both dirt-cheap and widely available. In fact, you can download good cryptographic software from the Internet for less than the price of a good pair of gloves.

Tomorrow's banks will be decentralized applications of software built on cryptography, blockchain technology and smart contracts. Theyll be platforms for saving, lending, investing, moving and spending that are much more equitable and sensible than they were in the 20th century and ironically it'll be more aligned to what banks were like in much earlier civilizations. So when I talk about banks being to the economy what the heart is to the human body - this is really what I'm talking about. I'm not necessarily talking about the ICBC. The ICBC or Bank of America may play an important role, but so could thousands of small local banks or small apps on a Blockchain.

Enigma was considered invulnerable, until the Poles revealed its weaknesses.

This apparently innocuous observation would lead to the first great breakthrough in cryptanalysis.

A little bit of math can accomplish what all the guns and barbed wire can't: a little bit of math can keep a secret.

Not afraid of heights - afraid of widths.

I describe Bitcoin as "a digital version of gold" eGold.

You’re British, you’re a priest, you’re a medical doctor, you can handle a rifle, you know Morse Code, and most importantly of all, you’re a fucking pain in the ass – so off you go!

The first known European book to describe the use of cryptography was written in the thirteenth century by the English Franciscan monk and polymath Roger Bacon. Epistle on the Secret Works of Art and the Nullity of Magic included seven methods for keeping messages secret, and cautioned: “A man is crazy who writes a secret in any other way than one which will conceal it from the vulgar.

like Turing and the cryptanalysts at Bletchley Park, the Navajo were ignored for decades. Eventually, in 1968, the Navajo code was declassified, and the following year the code talkers held their first reunion.

There is a remarkably close parallel between the problems of the physicist and those of the cryptographer. The system on which a message is enciphered corresponds to the laws of the universe, the intercepted messages to the evidence available, the keys for a day or a message to important constants which have to be determined. The correspondence is very close, but the subject matter of cryptography is very easily dealt with by discrete machinery, physics not so easily.” —Alan Turing

On the dimension of technology, the conflict has two poles: AI and crypto. Artificial Intelligence holds out the prospect of finally solving what economists call the “calculation problem”: AI could theoretically make it possible to centrally control an entire economy. It is no coincidence that AI is the favorite technology of the Communist Party of China. Strong cryptography, at the other pole, holds out the prospect of a decentralized and individualized world. If AI is communist, crypto is libertarian.

Cryptography is a science of deduction and controlled experiment; hypotheses are formed, tested and often discarded. But the residue which passes the test grows until finally there comes a point when the experimenter feels solid ground beneath his feet: his hypotheses cohere, and fragments of sense emerge from their camouflage. The code 'breaks'. Perhaps this is best defined as the point when the likely leads appear faster than they can be followed up. It is like the initiation of a chain-reaction in atomic physics; once the critical threshold is passed, the reaction propagates itself.

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. I have also observed that the cleverer the person, the more intimate is his conviction.

Propose to an Englishman any principle, or any instrument, however admirable, and you will observe that the whole effort of the English mind is directed to find a difficulty, a defect, or an impossibility in it. If you speak to him of a machine for peeling a potato, he will pronounce it impossible: if you peel a potato with it before his eyes, he will declare it useless, because it will not slice a pineapple.

A friend of ours encountered this problem with his home-built computer long ago. He wrote a BIOS that used a magic value in a particular memory location to determine whether a reset was a cold reboot or a warm reboot. After a while the machine refused to boot after power-up because the memory had learned the magic value, and the boot process therefore treated every reset as a warm reboot. As this did not initialize the proper variables, the boot process failed. The solution in his case was to swap some memory chips around, scrambling the magic value that the SRAM had learned. For us, it was a lesson to remember: memory retains more data than you think.

There was nothing I could do except homework. I cracked open Forsyth’s Basics of Cryptography, read until my eyes went bleary, then looked at my clock and saw it was only four thirty in the afternoon. Time really crawled when you were on lockdown. I struggled through another chapter, nodding off seventeen or eighteen times, then checked my clock again. It was still four thirty in the afternoon. Either time really crawled when you were on lockdown or my clock was broken. I checked my phone. In fact, it was eight thirty at night, which explained why I was so darn hungry. No one had come to get me for dinner. I wondered if this was part of my punishment or if the administration had simply forgotten about me. I’d now been at spy school long enough to guess it was the latter, which began to worry me. I could get through the night without food, but if someone didn’t remember I was in the Box by the next morning, things could get dicey. Still, it wasn’t worth panicking yet. Maybe this was merely a test to see how I handled pressure. If so, I’d show them I was a tough egg to crack. For the benefit of any cameras that might have been on me, I played it cool, as though I were really enjoying being on lockdown. I laid back on my cot and gave a contented sigh. “This is great,” I said to any concealed microphones. “All this time to myself. It’s like being on vacation.” Then I casually examined my clock to see if I could keep it from telling me that it was eternally four thirty in the afternoon.

Back in 2015, a volunteer group called Bitnation set up something called the Blockchain Emergency ID. There’s not a lot of data on the project now, BE-ID - used public-key cryptography to generate unique IDs for people without their documents. People could verify their relations, that these people belonged to their family, and so on. It was a very modern way of maintaining an ID; secure, fast, and easy to use. Using the Bitcoin blockchain, the group published all these IDs on to a globally distributed public ledger, spread across the computers of every single Bitcoin user online - hundreds of thousands of users, in those times. Once published, no government could undo it; the identities would float around in the recesses of the Internet. As long as the network remained alive, every person's identity would remain intact, forever floating as bits and bytes between the nations: no single country, government or company could ever deny them this. “That was, and I don't say this often, the fucking bomb,” said Common, In one fell swoop, identities were taken outside government control. BE-ID, progressing in stages, became the refugees' gateway to social assistance and financial services. First it became compliant with UN guidelines. Then it was linked to a VISA card. And thus out of the Syrian war was something that looked like it could solve global identification forever. Experts wrote on its potential. No more passports. No more national IDs. Sounds familiar? Yes, that’s the United Nations Identity in a nutshell. Julius Common’s first hit - the global identity revolution that he sold first to the UN, and then to almost every government in the world - was conceived of when he was a teenager.

Those “weird evolutions” enabled by a CTC, Ringbauer notes, would have remarkable practical applications, such as breaking quantum-based cryptography through the cloning of the quantum states of fundamental particles. “If you can clone quantum states,” he says, “you can violate the Heisenberg uncertainty principle,” which comes in handy in quantum cryptography because the principle forbids simultaneously accurate measurements of certain kinds of paired variables, such as position and momentum. “But if you clone that system, you can measure one quantity in the first and the other quantity in the second, allowing you to decrypt an encoded message.

Even after the aliens from Andromeda land with their massive spaceships and undreamed-of computing power, they will not be able to read the Soviet spy messages encrypted with one-time pads (unless they can also go back in time and get the one-time pads).

Step 1: The sender places the present in the briefcase, which they lock with their padlock and remove their key. They then send the locked briefcase to the receiver. Note: While the briefcase is en route from sender to receiver, it is safe from all adversaries, because they cannot remove the padlock from the briefcase. However, the receiver is also unable to obtain the present. Step 2: The receiver locks the briefcase with their own padlock and removes the key. They then return it to the sender. Note: The briefcase is now locked with two padlocks so no one can get the present. Step 3: The sender uses their own key to remove their padlock from the briefcase and returns the briefcase to the receiver. Note: The only lock on the briefcase belongs to the receiver. Step 4: The receiver removes their padlock from the briefcase to obtain the present.

In this simplistic example we have to admit that the sender has no way of knowing whose padlock is on the briefcase and that it might be possible for an adversary to impersonate the receiver and place their padlock on the briefcase. This is a problem that has to be addressed. The ‘Whose padlock is it?’ question in this briefcase example is similar to the ‘Whose public key is it?’ question that is so important when public key systems are used.

Numbers are unique, there is nothing like them and this book reveals something of their mysterious nature. Numbers are familiar to everyone and are our mainstay when we feel the need to bring order to chaos. In our own minds they epitomize measured rationality and are the key tool for expressing it. However, do they really exist?

Let us speak no more of faith in man, but bind him down from mischief by the chains of cryptography.

Something that looks like a protocol but does not accomplish a task is not a protocol—it’s a waste of time.

two forms of distribution, each release has a PGP signature file associated withit.* Prior to V8.11, this was a single signature file used to verify the uncompressed file, meaning that you needed to uncompress the tar(1) file before verifying it. Beginning with V8.11, there is a signature file for each of the compressed files, so there is no need to uncompress either first. The signature file has the same name as the distribution file but with a literal . sig suffix added.sendmail.8.14.1. tar.gz ← the distribution file sendmail.8.14.1. tar.gz.sig ← the signature file for this distribution file sendmail.8.14.1. tar.Z ← the distribution file sendmail.8.14.1. tar.Z.sig ← the signature file for this distribution file If you have not already done so for an earlier sendmail distribution, you must now download and install the PGPKEYS file from sendmail.org: ftp://ftp.sendmail.org/pub/sendmail/P... After downloading this file, add the keys in it to your PGP key ring with a command like this: pgp -ka PGPKEYS ← for pgp version 2. x pgpk -a PGPKEYS ← for pgp version 5. x gpg --import PGPKEYS ← for gpg If you use gpg(1), your output may look something like this: % gpg --import PGPKEYS gpg: key 16F4CCE9: "Sendmail Security " 22 new signatures gpg: key 7093B841: public key "Sendmail Signing Key/2007 " imported gpg: key AF959625: "Sendmail Signing Key/2006 " 7 new signatures gpg: key 1EF99251: "Sendmail Signing Key/2005 " 9 new signatures gpg: key 95F61771: "Sendmail Signing Key/2004 " 7 new signatures gpg: key 396F0789: "Sendmail Signing Key/2003 " 27 new signatures gpg: key 678C0A03: "Sendmail Signing Key/2002 " 13 new signatures * How public key cryptography is used to sign a file is described in §5.2 on page 1992.2 Download the Source | 43 This is the Title of the Book, eMatter Edition Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

The function of cryptographic protocols is to minimize the amount of trust required.

Laruelle endorses identity of the same, not heterogeneity or difference; his non-standard method requires ascetic withdrawal, not the kind of self-realization associated with the “me generation” of post-1968 philosophy; his ontology is rooted in a cryptography of being, not the more popular pornography of being (evident in the virtues of transparency, the strategies of capture, or the logics of aletheia); he requires a unilateral relation, not today’s hegemony of multilateral ecologies of difference (assemblages, rhizomes, networks). No wonder that Laruelle has been overlooked for so many years.

The correct use of a strong cipher is a clear boon to sender and receiver, but the misuse of a weak cipher can generate a very false sense of security.

Alan Turing was another cryptanalyst who did not live long enough to receive any public recognition. Instead of being acclaimed a hero, he was persecuted for his homosexuality. In 1952, while reporting a burglary to the police, he naively revealed that he was having a homosexual relationship. The police felt they had no option but to arrest and charge him with “Gross Indecency contrary to Section 11 of the Criminal Law Amendment Act 1885.” The newspapers reported the subsequent trial and conviction, and Turing was publicly humiliated. Turing’s secret had been exposed, and his sexuality was now public knowledge. The British Government withdrew his security clearance. He was forbidden to work on research projects relating to the development of the computer. He was forced to consult a psychiatrist and had to undergo hormone treatment, which made him impotent and obese. Over the next two years he became severely depressed, and on June 7, 1954, he went to his bedroom, carrying with him a jar of cyanide solution and an apple. Twenty years earlier he had chanted the rhyme of the Wicked Witch: “Dip the apple in the brew, Let the sleeping death seep through.” Now he was ready to obey her incantation. He dipped the apple in the cyanide and took several bites. At the age of just forty-two, one of the true geniuses of cryptanalysis committed suicide.

The three Britons had to sit back and watch as their discoveries were rediscovered by Diffie, Hellman, Merkle, Rivest, Shamir and Adleman over the next three years.

Lyndon Johnson and Richard Nixon were guilty of unjustified wiretaps, and President John F. Kennedy conducted dubious wiretaps in the first month of his presidency.

Even the Vatican, probably the second most active center of cryptanalysis, would send Soro seemingly impenetrable messages that had fallen into its hands. In 1526, Pope Clement VII sent him two encrypted messages, and both were returned having been successfully cryptanalyzed.

The Vigenère cipher was called “le chiffre indéchiffrable,” but Babbage broke it;

He was a rather quirky worker, and he didn’t really fit into the day-to-day business of GCHQ. But in terms of coming up with new ideas he was quite exceptional. You had to sort through some rubbish sometimes, but he was very innovative and always willing to challenge the orthodoxy.

We would be in real trouble if everybody in GCHQ was like him, but we can tolerate a higher proportion of such people than most organizations. We put up with a number of people like him. Figure 66 James Ellis. (photo credit 6.4) One of Ellis’s greatest qualities was his breadth of knowledge.

in the 1980s it was only government, the military and large businesses that owned computers powerful enough to run RSA. Not surprisingly, RSA Data Security, Inc., the company set up to commercialize RSA, developed their encryption products with only these markets in mind.

Zimmermann believed that everybody deserved the right to the privacy that was offered by RSA encryption, and he directed his political zeal toward developing an RSA encryption product for the masses.

Zimmermann employed a neat trick that used asymmetric RSA encryption in tandem with old-fashioned symmetric encryption.

In June 1991 he took the drastic step of asking a friend to post PGP on a Usenet bulletin board. PGP is just a piece of software, and so from the bulletin board it could be downloaded by anyone for free. PGP was now loose on the Internet.

For decades, ENIAC, not Colossus, was considered the mother of all computers.

NSA employs more mathematicians, buys more computer hardware, and intercepts more messages than any other organization in the world. It is the world leader when it comes to snooping.

In the 1970s, banks attempted to distribute keys by employing special dispatch riders who had been vetted and who were among the company’s most trusted employees.

dispatch riders would race across the world with padlocked briefcases, personally distributing keys to everyone who would receive messages from the bank over the next week. As business networks grew in size, as more messages were sent, and as more keys had to be delivered, the banks found that this distribution process became a horrendous logistical nightmare, and the overhead costs became prohibitive.

A large amount of identically encrypted material provides a cryptanalyst with a correspondingly larger chance of identifying the key.

the Germans therefore took the clever step of using the day key settings to transmit a new message key for each message.

many shipwrecks and engineering disasters were blamed on faulty tables. These mathematical tables were calculated by hand, and the mistakes were simply the result of human error. This caused Babbage to exclaim, “I wish to God these calculations had been executed by steam!” This marked the beginning of an extraordinary endeavor to build a machine capable of faultlessly calculating the tables to a high degree of accuracy. In 1823 Babbage designed “Difference Engine No. 1,” a magnificent calculator consisting of 25,000 precision parts, to be built with government funding. Although Babbage was a brilliant innovator, he was not a great implementer. After ten years of toil, he abandoned “Difference Engine No.

Vigenère’s work culminated in his Traicté des Chiffres (“A Treatise on Secret Writing”), published in 1586. Ironically, this was the same year that Thomas Phelippes was breaking the cipher of Mary Queen of Scots. If only Mary’s secretary had read this treatise, he would have known about the Vigenère cipher, Mary’s messages to Babington would have baffled Phelippes, and her life might have been spared.

the Vigenère cipher belongs to a class known as polyalphabetic, because it employs several cipher alphabets per message. The polyalphabetic nature of the Vigenère cipher is what gives it its strength, but it also makes it much more complicated to use. The additional effort required in order to implement the Vigenère cipher discouraged many people from employing it.

French listening posts learned to recognize a radio operator’s fist. Once encrypted, a message is sent in Morse code, as a series of dots and dashes, and each operator can be identified by his pauses, the speed of transmission, and the relative lengths of dots and dashes. A fist is the equivalent of a recognizable style of handwriting.

copies were passed to the cryptanalysts, who sat in little kiosks, ready to tease out the meanings of the messages. As well as supplying the emperors of Austria with invaluable intelligence, the Viennese Black Chamber sold the information it harvested to other powers in Europe. In 1774 an

it can be mathematically proved that it is impossible for a cryptanalyst to crack a message encrypted with a onetime pad cipher. In other words, the onetime pad cipher is not merely believed to be unbreakable, just as the Vigenère cipher was in the nineteenth century, it really is absolutely secure

it requires a great deal of time, effort and money to create a random key. The best random keys are created by harnessing natural physical processes, such as radioactivity, which is known to exhibit truly random behavior. The cryptographer could place a lump of radioactive material on a bench, and detect its emissions with a Geiger counter. Sometimes the emissions follow each other in rapid succession, sometimes there are long delays—the time between emissions is unpredictable and random. The cryptographer could then connect a display to the Geiger counter, which rapidly cycles through the alphabet at a fixed rate, but which freezes momentarily as soon as an emission is detected.

the hotline between the presidents of Russia and America is secured via a onetime pad cipher.

impenetrability of the Navajo code was all down to the fact that Navajo belongs to the Na-Dene family of languages, which has no link with any Asian or European language.

a Navajo verb is conjugated not solely according to its subject, but also according to its object. The verb ending depends on which category the object belongs to: long (e.g., pipe, pencil), slender and flexible (e.g., snake, thong), granular (e.g., sugar, salt), bundled (e.g., hay), viscous (e.g., mud, feces) and many others. The verb will also incorporate adverbs, and will reflect whether or not the speaker has experienced what he or she is talking about, or whether it is hearsay. Consequently, a single verb can be equivalent to a whole sentence, making it virtually impossible for foreigners to disentangle its meaning.

Major General Howard Conner, “without the Navajos, the marines would never have taken Iwo Jima.

It is quite possible that British Intelligence demanded that Babbage keep his work secret, thus providing them with a nine-year head start over the rest of the world.

imagined a machine whose internal workings could be altered so that it could perform all the functions of all conceivable Turing machines. The alterations would be made by inserting carefully selected tapes, which transformed the single flexible machine into a dividing machine, a multiplying machine, or any other type of machine. Turing called this hypothetical device a universal Turing machine because it would be capable of answering any question that could logically be answered. Unfortunately, it turned out that it is not always logically possible to answer a question about the undecidability of another question, and so even the universal Turing machine was unable to identify every undecidable question.

Turing knew of Babbage’s work, and the universal Turing machine can be seen as a reincarnation of Difference Engine No. 2. In fact, Turing had gone much further, and provided computing with a solid theoretical basis,

The fundamental weakness of the Vigenère cipher is its cyclical nature. If the keyword is five letters long, then every fifth letter of the plaintext is encrypted according to the same cipher alphabet. If the cryptanalyst can identify the length of the keyword, the ciphertext can be treated as a series of five monoalphabetic ciphers, and each one can be broken by frequency analysis. However, consider what happens as the keyword gets longer. Imagine a plaintext of 1,000 letters encrypted according to the Vigenère cipher,

The fate of the Polish nation had depended on Rejewski, and he did not disappoint his country. Rejewski’s attack on Enigma is one of the truly great accomplishments of cryptanalysis.

By depriving Rejewski of the keys, Langer believed he was preparing him for the inevitable time when the keys would no longer be available. He knew that if war broke out it would be impossible for Schmidt to continue to attend covert meetings, and Rejewski would then be forced to be self-sufficient. Langer thought that Rejewski should practice self-sufficiency in peacetime, as preparation for what lay ahead.

Rejewski had vastly simplified the task of finding the day key by divorcing the problem of finding the scrambler settings from the problem of finding the plugboard settings. On their own, both of these problems were solvable. Originally, we estimated that it would take more than the lifetime of the universe to check every possible Enigma key. However, Rejewski had spent only a year compiling his catalogue of chain lengths, and thereafter he could find the day key before the day was out. Once he had the day key, he possessed the same information as the intended receiver and so could decipher messages just as easily.

quantum cryptography is a system that ensures the security of a message by making it hard for Eve to read accurately a communication between Alice and Bob. Furthermore, if Eve tries to eavesdrop then Alice and Bob will be able to detect her presence. Quantum cryptography therefore allows Alice and Bob to exchange and agree upon a onetime pad in complete privacy, and thereafter they can use this as a key to encrypt a message.

Quantum cryptography is an unbreakable system of encryption.

When Hermann Göring visited Warsaw in 1934, he was totally unaware of the fact that his communications were being intercepted and deciphered. As he and other German dignitaries laid a wreath at the Tomb of the Unknown Soldier next to the offices of the Biuro Szyfrów, Rejewski could stare down at them from his window, content in the knowledge that he could read their most secret communications.

Babbage’s successful cryptanalysis of the Vigenère cipher was probably achieved in 1854, soon after his spat with Thwaites, but his discovery went completely unrecognized because he never published it. The discovery came to light only in the twentieth century, when scholars examined Babbage’s extensive notes. In the meantime, his technique was independently discovered by Friedrich Wilhelm Kasiski, a retired officer in the Prussian army. Ever since 1863, when he published his cryptanalytic breakthrough in Die Geheimschriften und die Dechiffrir-kunst (“Secret Writing and the Art of Deciphering”), the technique has been known as the Kasiski Test, and Babbage’s contribution has been largely ignored.

He took the messages to a local brewer, who wrapped them in a leather packet, which was then hidden inside a hollow bung used to seal a barrel of beer. The brewer would deliver the barrel to Chartley Hall, whereupon one of Mary’s servants would open the bung and take the contents to the Queen of Scots. The process worked equally well for getting messages out of Chartley Hall.

When ships carrying COMSEC material came into dock, crypto-custodians would march onboard, collect stacks of cards, paper tapes, floppy disks, or whatever other medium the keys might be stored on, and then deliver them to the intended recipients.