Kryptos is a long-unsolved cryptographic sculpture—a piece of art with encoded messages—located outside the CIA's headquarters.

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.

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.

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.

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.

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.

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 "crypto-" in cryptocurrencies like bitcoin refers to the mathematical functions that generate pairs of public and private keys and encrypt data in blocks. When combined, these systems secure transactions on the network, verify digital asset and token transfers, and contribute to end-user anonymity.

At 33 Thomas Street in Lower Manhattan, New York City, a 45-story concrete tower with no windows stands imperiously over the city. Inside, 18 floors of telecommunications technology have hummed for decades. The building's purpose—to protect US comms from nuclear fallout—and its design have played into spy movie plotlines. Dive into the building's curious role in pop culture with this long read.

This fortified vault, built in 1936, is part of the US Mint, but it doesn’t create any currency. Only a presidential order can open Fort Knox—there has not been an audit of its contents since 1953.

In 2020, the Perseverance Rover landed on Mars, sending a message for the folks back home on its parachute. It took fewer than six hours for the Internet's collective forces to decode the secret slogan hidden in the parachute's colors and patterns, as well as the geographic coordinates of the earth-bound place where rocketry was perfected.

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.

One of the most famous archaeological finds of all time, the 1799 discovery of the Rosetta Stone helped unlock the secrets of ancient Egypt. Inscribed on the granite slab was the same passage in three languages: hieroglyphics, Old Egyptian, and Greek, which enabled scholars to decode the ancient language. Take an up-close look with this 3D model made up of more than 200 composite photos.

Although they appear to be performance artists, the group claims they're earnestly protesting the captivity of a man inside the iconic public art piece designed by Anish Kapoor. City officials say there is no man inside the object.

The site includes installations, sculptures, textiles, musical pieces, and galleries inspired by malicious software and related technologies, including the ILOVEYOU virus, encryption protocols from ransomware attacks, and the Industroyer malware framework used by Russia to cut power to Ukraine.

Developed by the US Army and US Navy, over 10,000 of these machines were deployed by the end of World War II to encrypt messages for the armed forces using three series of rotors. The device would continue to be used until the 1950s, while personal computers were shown to possess enough computing power to crack it by 2021.

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.

A living archive of humanity’s ancient art and symbols, our shared history that is embedded as rock art and cave art in the landscape

In the 1980s, archaeologists finally deciphered Maya hieroglyphs in part by identifying known words. Maya scholar David Stuart notes that cacao—still used today—was one of the key linguistic anchors that unlocked ancient Maya texts.

Mount Rushmore was designed to be more than a massive monument to US presidents, and its ambitious plans were part of the reason why. This fascinating video explores its backstory, creation, and the hidden tunnel behind President Lincoln's head.

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.

The Persistence of Memory was painted on a canvas roughly the size of a sheet of paper, depicting a desolate landscape with melting clocks, ants, and a distorted figure. The piece incorporates Freud and Einstein's ideas, resulting in a haunting composition symbolizing time's fluidity and Dalí's personal anxieties.

On October 19, 2025, several people dressed as construction workers climbed a construction lift and broke into the Louvre, stealing roughly $100M of crown jewels. This podcast breaks down the specifics of the heist.

A look at the biggest cryptocurrency heists, be they from an exchange, smart contract, or a business, including amounts, methods, reparations, and consequences.

The Black Vault is one of the largest privately run archives of declassified documents in the world. Explore UFO sightings, doorways on Mars, and more.

The Rosicrucian Egyptian Museum houses the largest collection of Egyptian artifacts on exhibit in western North America. Located in San Jose, California, the museum is home to over 4,000 artifacts, including four mummified individuals. The institute was founded by the centuries-old mystical Rosicrucian brotherhood, a group which claims special awareness of ancient wisdom. Take a 3D tour, complete with descriptions of some its most famous pieces.

The blog aggregates art, design, fashion, and technology from the atomic and space age, spanning mid-century American futurism and its Soviet counterpart. The content has a broad range: escape pods from a B-58 bomber sit alongside Tour de France caravan vehicles and unidentified industrial designs.

In October 1962, NSA cryptographer Juanita Moody headed analysis of U‑2 surveillance data and urgently produced intelligence on Soviet missile deployments in Cuba. Her reports drove high-level US decision-making, and were critical to avoiding nuclear war during the Cuban Missile Crisis.

Egypt's ancient marvel, the 66-foot, 4,500-year-old Great Sphinx, is believed to stand as a guard to the great Giza pyramids—or tombs—of pharaohs Khafre and Khufu. Archaeologists have long debated which of the two leaders' faces is on the great monument, the father (Khufu) or the son (Khafre).

The crystal skulls long displayed as Aztec artifacts were actually fabricated in the late 1800s, all linked to French antiquities dealer Eugène Boban. Anthropologist Jane Walsh's investigation exposed their modern origins, overturning a century of mistaken museum lore.

When legendary musician Prince died in 2016, he left behind thousands of unreleased songs in a locked vault, and no one knew the combination (even Prince had forgotten it before his death). Safecracker Dave McOmie was called in to break the 6,000-pound Mosler American Century vault by microdrilling into it and using a periscope to view the combination lock.

Alex Karp is well-known for being outspoken both about his own beliefs and about the role of Palantir in protecting Western civilization. Karp has said that while supporting government institutions doesn't always mean supporting every policy or decision those institutions make, not allowing Immigration and Customs Enforcement to access Palantir's services would go against the company's central mission of supporting Western democracy.

To maintain secrecy, the US built three remote research facilities and entire “secret cities” to house thousands of workers and families. These communities—home to tens of thousands—were omitted from official maps until after World War II.

On March 18, 1990, the thieves entered Isabella Stewart Gardner Museum pretending to be police officers responding to a disturbance. After overpowering and handcuffing the guards on duty, they stole 13 precious items, including works by Rembrandt and Manet. The theft is the largest art heist in US history. The pieces are still missing, and the museum is offering a $10M reward to anyone who provides valuable information about their location.

Ötzi the Iceman, discovered in 1991, is one of the oldest human mummies ever found—and his 61 tattoos remain a mystery. This explainer looks at how researchers believe the tattoos were made, what their placement suggests about ancient medicine and culture, and why we’re still piecing together their true purpose today.

Digital currencies based solely on misspellings of former President Joe Biden’s name have skyrocketed, and backers of a token based on a Shiba Inu wearing a hat raised $690K to get their logo on the Las Vegas Sphere.

A pseudonym used by the person or group of people who created bitcoin—the first decentralized cryptocurrency—the real identity of Satoshi Nakamoto has baffled millions of enthusiasts for years.

The espionage franchise is all about secret codes, including one embedded in its popular theme song. The opening notes are based on Morse code, which translates to "M" and "I."

This five-minute video details the accidental discovery and subsequent decoding of the first known sentence in what's believed to be the oldest written alphabet. The Canaanite sentence was found on a Bronze Age hair comb unearthed in Tel Lachish, a city of the ancient Biblical Kingdom of Judah, during a dig focused on excavating the kingdom's first Iron Age city. The Canaanite language developed sometime between 3,000 and 1,000 BCE.

A number of heists have taken place in just a few minutes, relying on a small team and minor weapons. Once pieces are stolen, some are sold as high-quality replicas, leaving art collectors unknowingly holding original masterpieces in their collections.

While crypto feels new, it actually dates to 1983, with eCash's creation. However, a lot has happened in the crypto world over the past few years in particular—crypto's market cap surpassed $2T for the first time in 2021, for instance. A timeline of crypto's history details the events in between.

Known by some as the "Indiana Jones of the art world," Arthur Brand has recovered more than 150 stolen paintings and artifacts. He works independently, existing as a helpful bridge between the police and the people who might know where the stolen art is hiding. He is motivated by the thrill of the chase more than any financial payoff.

Discoveries in Belize's Actun Tunichil Muknal (ATM) cave suggest the cave was once a significant site for sacred Mayan ceremonies in antiquity. New research reveals how the Mayans conducted rituals to re-enact a specific creation myth, often staged in desperate times and aimed to invoke the gods for a "rebirth" amid drought and turmoil. Read more on the enigmatic research here.

Andreessen Horowitz (a16z) is a leading venture capital firm with deep expertise in cryptocurrency and blockchain technology. For 10 years, the firm has built its internal knowledge in the area, and archived a wide range of explainers exploring everything from fundamentals to emerging crypto trends, and much more.

The graffito appeared seemingly everywhere throughout the 1940s and followed a similar pattern: A man with an oversized nose peering over a ledge, with the phrase written below it. Scholars believe it was an American form of similar tags that appeared in Australia and England, making "Kilroy" a meme long before the word had entered the lexicon.

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.