The history and operation of SIGABA, the US counterpart of the Nazi Enigma machine

Watch how the Enigma machine encrypts messages and learn about its critical design flaw

Using settings selected from a series of rotors and a plugboard that let operators swap letters with any of their choosing, the machine lit up the output letter for each letter typed. While this system could generate messages requiring any of 150 quintillion potential keys, the machine's reflector never encrypted a letter as itself, providing an entry point for exploiting the system.

Jacqueline Jenkins-Nye—Bill Nye's mother—worked as a code-breaker in World War II

While in the Navy, she was recruited to work on Enigma to help decode messages from the German military. Historians estimate that the efforts of code-breakers may have collectively shortened the war by as much as two years.

A look at historical ciphers, from the Spartan 'scytale' to the Navajo Code Talkers

From the Greek word for "hidden writing," cryptography in Ancient Greece took the form of batons around which a long strip of leather or parchment was wrapped, after which messages were written. Recipients needed a scytale of the correct width to encircle received ribbons and reveal the message. Members of the Navajo Nation created a code that remained unbroken throughout its use in World War II.

View how AES—the global standard for symmetric encryption—works

Established by the National Institute of Standards and Technology in 2001, the Advanced Encryption Standard transforms plaintext into ciphertext using multiple rounds of processing, including substitution, transposition, and mixing. Larger keys undergo more rounds to produce 16-byte blocks of scrambled data, with 256-bit AES keys taking 3.31 × 10⁵⁶ years to decrypt via brute force.

Grace Hopper was inspired to join the armed forces after the attack on Pearl Harbor

Despite being too old to enlist and weighing below the required minimum to serve, Hopper was granted an exemption and assigned to work on the first electromechanical computer produced in the US. She and her team spent three months using the device to solve equations needed to design the implosion mechanism for the atomic bomb.

Claude Shannon, for whom Anthropic's AI tools are named, proved the existence of an unbreakable cipher

In the one-time pad approach, the encryption key is randomly generated and of equal length to the plaintext. This randomness ensures that every possible plaintext is equally likely—RBBHN can mean HELLO, SOLVE, CODES, and so on, using a different key—while matching the message and key lengths prevents the appearance of patterns that can be exploited.

Practice encrypting and decrypting text using an online library of ciphers

This tool provides users with customizable protocols, including Caesar, Affine, and Vigenère ciphers, to hide messages in transformed text and convert them back into legible formats. Mechanisms are also available to convert text into other communication languages, such as Morse code and URL encoding.

Designed in 1937 by Harvard graduate student Howard H. Aiken, the 'Harvard Calculator' was used by the US Navy to solve advanced physics problems.

The first compiler to facilitate communication with computers was developed by Grace Hopper

The A-0 program linker automatically translated mathematical symbols into machine-readable binary code. Although it took two years for computer executives to get on board with the idea, the technology was foundational to future programming languages that allowed computers to understand commands written in word-based languages.

US secrets: Project Paperclip

The US launched Project Paperclip in 1946, covertly recruiting over 1,500 German scientists to advance American military and space programs. Among them was Wernher von Braun, a key architect of the V-2 rocket who later became instrumental in NASA’s Apollo missions. While these scientists accelerated technological breakthroughs, their recruitment raised moral debates about overlooking wartime affiliations in the name of progress—questions that remain unresolved today.

The science of cryptography, including methods to encrypt data and how to break encryption

Monoalphabetic ciphers use a set of rules to replace each letter with another consistently, making them susceptible to brute force attacks that try every kind of replacement. While more complex ciphers can transform text in less obvious ways, because certain letters are used more often than others, an analysis of letter frequency may reveal patterns that help uncover the rules that make up a cipher.

The first algorithmic random number generator was developed in 1946

Although previous methods of randomness involved physical tools with limited outcomes, such as dice, or relied on chaotic variables for number generation, such as electronic noise, John Von Neumann's middle-square method turned the problem into a mathematical computation. It has since been replaced by methods that generate numbers from unique initial values, such as the time on a clock.

A US Department of Defense research lab developed the technology for the dark web

Although encryption existed to mask the content of communications across the internet before the 1990s, those managing overseas network infrastructure could determine a spy's affiliation based on where they saw data sent to and received from. To keep this information secret, the US Naval Research Laboratory developed onion routing, which enabled anonymized web browsing. The release of the technology to the public obscured sensitive communications further by growing the volume of anonymous data.

How quantum computers can empower Shor's algorithm to break digital encryption

Secure communications largely rely on numeric keys generated by multiplying two enormous prime numbers together, and it is computationally impractical to determine these primes by trying to divide by every possible one. While Shor's algorithm can provide better guesses for this brute-force approach, it relies on a number that is difficult to determine on classical computers but much easier to calculate using the simultaneous computations enabled by quantum superposition.

How end-to-end encryption protects messages, even from service providers

Using symmetric and asymmetric cryptography, data is encrypted on the sender's device before being transmitted across application servers that lack the key needed to decrypt it. The message is not decrypted until it reaches the recipient's device, which uses their private key to recover the plaintext. E2EE's effectiveness has led to its adoption by WhatsApp and Signal.

Create your own cipher by combining mathematical operations and encryption protocols

This tool allows users to build an encryption workflow in which the output of one customizable function becomes the input to another, thereby creating undiscovered methods for obscuring information via a series of ciphers.

The US space program was built on former Nazi expertise through Operation Paperclip

After WWII, the US secretly recruited over 1,600 German scientists, including ex-Nazis like Wernher von Braun. They repurposed V‑2 rocket technology to create NASA’s core capabilities—pivotal in the Saturn V and Apollo missions.

The story of Kryptos, the long unsolved cryptographic sculpture outside the CIA's headquarters

Made by American artist Jim Sanborn, the sculpture features four copper plates engraved with messages written with the 26 letters of the Latin alphabet and question marks. The last of these plates was solved in 2025, but the piece remains of interest to cryptoanalysts.

The mathematics of quantum-based cryptography, and why existing data is already at risk

Seeing the potential of this technology, some governments and malicious actors are thought to have already started storing encrypted data, in the hopes that quantum computers within the next 10 to 20 years will be able to decrypt it. As of 2022, the National Institute of Standards and Technology had selected four algorithms for inclusion in a quantum-resistant encryption standard.

Among the smallest mass-produced mechanical calculators in history, the Curta was designed by Austrian engineer Curt Herzstark while imprisoned in a Nazi concentration camp during World War II.

The history of ARPANET and how it helped the US military during the Cold War

President Dwight D. Eisenhower established the Advanced Research Projects Agency in 1958, which recruited scientists to design the first large-scale computer network to support the American military during the Cold War. Academics would use the network to communicate via email among several US research universities.

Before transistors, which regulate the flow of electricity, vacuum tubes—glass tubes containing no gas that resemble light bulbs—served as the electronic switches in computers.

A mathematical breakdown of how RSA encryption uses prime numbers to encrypt data

This form of asymmetric cryptography uses mathematical functions that rely on the product of two large prime numbers. Because traditional computers struggle to factor such products, obtaining the private keys needed to decrypt messages becomes effectively impossible. This security can be reinforced with larger prime numbers, though this makes encryption more computationally taxing.

Arnold Schoenberg designed a musical typewriter that transcribed complex compositions with a simple keyboard.

FLOW-MATIC was the first programming language resembling the English language

As part of the team working on UNIVAC—the first commercially produced electronic digital computer in the US—Grace Hopper helped develop the system that enabled nonprogrammers and businesspeople without a strong mathematics background to use the machine effectively, thereby enhancing the computer's commercial viability.

When German submarines lurked in US coastal waters

During World War II, German submarines (also known as U-boats) prowled the Southern coast of the US in 1942 and 1943, sinking more than 60 ships and killing 600 Allied soldiers. The campaign is less well-known, since the major battles in Stalingrad and Midway happened at the time. Several of these submarines and the ships they sank are now popular diving spots.

The story of two female programmers running the simulations behind chaos theory's discovery

Margaret Hamilton and Ellen Fetter worked on MIT's 800-pound Royal McBee LGP-30 computer, which was fed binary code on paper tape to perform computations. Among the computations performed were those involving equations describing the motion of gas in a circulating fluid for Edward Lorenz, widely considered the father of chaos theory.

Explore a visual guide to how quantum computers can crack RSA encryption

In 1994, Peter Shor introduced an algorithm that showed a quantum computer could efficiently factor the product of two very large prime numbers, undermining the mathematics that makes RSA so secure. While using larger keys can delay the decryption time of quantum computers, this solution increases the time it takes to encrypt data, which may become impractical.

Nazi Germany replaced Advent calendars with depictions of family life under Nazi rule

During World War II, the Nazi regime banned printed Advent calendars because of religious messaging. Officials instead produced state-approved versions featuring swastikas, tanks, and Nazi symbols.

Can you save Britain from the Nazis by carefully sharing secrets with America?

Find out in this 20-minute interactive graphic novel based on true events from World War II.

World War II's Battle of Savo Island was the worst wartime naval defeat in US history

On Aug. 9, 1942, a larger, radar-equipped Allied fleet lost four heavy cruisers off Guadalcanal in the Pacific theater without sinking a single Japanese ship. The Navy kept the humiliating rout secret from the public for years. Experts argued failure resulted from fractured command, not inferior arms or ships.

The Japanese Navy used radio silence and deception to mask its approach

In late November 1941, Japan’s carrier strike force maintained total radio silence while operators back home broadcast normal traffic—creating ambiguity about the location of the fleet. The deception obscured US intelligence and helped create a surprise attack.

Computer pioneer Alan Turing was also an elite runner

Alan Turing is credited with helping to found modern computer science, in addition to cracking the Nazi code known as Enigma. Beyond these world-historical achievements, the British mathematician also nearly represented his country in the Olympics in the marathon, running just 11 minutes slower than the eventual gold recipient at the 1948 games. Read more on this lesser-known aspect of the man here.

US intelligence failures contributed to the success of the Japanese attack

Despite breaking Japan’s diplomatic codes, US agencies failed to integrate warnings, successfully track Japan’s carriers, or even believe a Hawaii strike was possible (they also had not cracked Japan’s naval codes). Missed signals, ignored reports and poor coordination led to one of the worst intelligence failures in US history.

The Antikythera mechanism: The oldest-known analog computer

A device now considered the world's oldest computer was pulled from a shipwreck more than 120 years ago. Known as the "Antikythera Mechanism," it is now believed to have allowed precise tracking of astronomical positions, and its sophistication overturned understanding of Ancient Greek capabilities.

Explore (digitally) the Computer History Museum

When IBM’s Deep Blue supercomputer won its famous chess rematch with then world champion Garry Kasparov in May 1997, the victory was hailed far and wide as a triumph of artificial intelligence. But John McCarthy—the man who coined the term and pioneered the field of AI research—didn’t see it that way. An obituary about McCarthy—who passed in 2001—and his ideas.

The first commercially successful calculating machine—the arithmometer—was patented in 1820 but not mass-produced for over three decades, likely because its inventor was focused on his insurance business.

The Majorana 1 chip may provide quantum computing using geometry-based qubits

Traditional quantum computers are incredibly fragile, with encoded information easily disrupted and requiring significant error correction systems. Microsoft’s approach involves storing data on a surface, which is more stable, but involves an elusive particle first theorized in 1938.

A timeline of how Claude Code was used to execute cyberespionage

In September 2025, a Chinese state-sponsored group targeted 30 large tech companies, financial institutions, chemical manufacturing companies, and government agencies by manipulating Claude Code, having succeeded in infiltrating a small subset. The cyberattack is believed to have been the first of its scale carried out without major human intervention.

Efforts to find Majorana particles may finally lead to reliable quantum computers

Though the particle—which is its own antiparticle—remains theoretical, scientists from Microsoft to Google continue developing systems to mimic this property towards building error-resistant quantum computers. Scientists at UCSB have been attempting to get the particle using just pencil lead and Scotch tape.

German printer Richard Sellmer revived Advent calendars after World War II

Advent calendar production resumed in 1946, when German printer Richard Sellmer began issuing nostalgic winter-town designs that became classics, later exporting them to the United States. His company still operates today, producing more than 140 varieties.

How the NSA has changed through history

The National Security Agency was born in the Cold War and then transformed by 9/11. This article answers all the basic questions you might have about the NSA, from what it does to how much data it collects to some of its useful intercepts.

Noise and instability made quantum computing seem out of reach for decades

Recent advances in error suppression, mitigation, and correction are allowing quantum computers to perform practical tasks that challenge classical machines. IBM’s 2016 launch of its first cloud-accessible quantum computer attracted over 22,000 users in its first month alone.

Grace Hopper described serving in the US Navy as the highest award she received

Despite retiring from the US Naval Reserve in 1966 at 60, as stipulated by Navy regulations, Hopper was repeatedly recalled for her pioneering expertise in computer science. By 1983, three years before her final retirement, she would give lectures about 200 days a year to computer scientists at military bases, college campuses, and businesses on behalf of the Navy.

Security technician hacks a voting machine to reveal its vulnerabilities

A technician bought an old, likely-decommissioned voting machine from 2013 and took it apart to see how a would-be hacker might be able to exploit its vulnerabilities. Get a sense of the needs for secure, up-to-date voting machines with this...

More than 2,000 years ago, a hand-powered model of the solar system called the Antikythera mechanism—the oldest example of an analog computer—could predict solar eclipses.

An explanation of Turing machines—the foundations of digital algorithms and computers

The device reads data, overwrites or ignores it, and then moves on to the next piece of data based on a set of programmed rules. By imagining this data as zeros and ones—binary that makes up computer code—Turing machines became the theoretical models for how any algorithm could be run on a computer if the procedure could be coded into a set of digital rules.

The food processing techniques developed for World War II, later repurposed for consumers

Research projects funded or sponsored by the military led to the development of active dry yeast to make bread easier to bake and an improved version of dehydrated cheese, which would be used in powdered cheese snacks. Freeze-drying, which had been used to ease the transport of blood plasma to battlefields, where it would be reconstituted with water, was later used on fruit for cereals.

How the US first installed an electronic fence along the southern border

The US Border Patrol's first automated surveillance system launched in 1970 with 177 ground sensors installed along a single section in California. The sensors had already been used in Vietnam, along the so-called McNamara Line, and were connected by radio transmitters to magnetic-tape computers. They were implemented to target people defined by law and deportable aliens.

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.