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

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.

Visualize how passkeys, which rely on asymmetric cryptography to authenticate users, work

After using biometrics or a PIN to access the private key stored on a device, it is combined with a random number generated by the site to produce a cryptographic signature. This signature is verified using the site's public key, allowing a user to log in without entering a password. This reduces the risk of fraudulent messages—phishing attacks—and data breaches.

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.

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.

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.

Technical vulnerabilities prevent full-proof anonymity when browsing the dark web

Despite encrypting data and relaying it within the Tor network, traffic between the network exit and the final destination is no longer hidden and can be captured. Law enforcement agencies can also attempt to deanonymize users by monitoring and matching data signal patterns entering and leaving the network via a correlation algorithm.

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

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.

The dark web protects free speech from censorship and authoritarian oversight

Encrypted networks allow users with internet access anywhere in the world to view blocked content and avoid surveillance when communicating evidence of abuse to independent journalists. The same networks can support democracies by helping activists coordinate protests on dark web forums.

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.

A visual guide to how bitcoin transactions work and rely on cryptography

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.

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.

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.

Creating a digital alternative to the traditional Chinese 'red envelope' payments helped spur WeChat's financial services growth, and helped it become a 'superapp.'

Read a breakdown of WeChat, the central technology in Tencent's empire that boasts roughly 1.4 billion users and hosts e-commerce, payment, and messaging services all in one place.

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.

Meta has reported WhatsApp users send over 100 billion messages daily

Across 180 countries and 60 languages, approximately billion users use the messaging app every day, with about 400 million in India, WhatsApp's biggest market. In some countries, the app has gone beyond messaging, enabling users to schedule doctor's appointments, conduct real estate deals, and provide direct-to-consumer sales.

Onion routing disguises internet traffic in layers resembling a nesting doll

Data is encrypted at least three times before being sent to a node—a server that can only decrypt one layer. Then, the underlying encrypted data is relayed to another node, and the process repeats until all layers are decrypted. Thousands of possible nodes make it extremely difficult to trace activity within the system.

Understanding the Diffie-Hellman key exchange, an example of public key cryptography

Published in 1976 by Whitfield Diffie and Martin Hellman, the system involves two parties combining each of their unique private keys with a public key using a mathematical function. The combinations are exchanged and mixed to establish a common key that no third party can determine. The Diffie-Hellman system underlies many encryption protocols for internet traffic.

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.

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.

Critics say WeChat is a surveillance tool for the Chinese government.

How hash functions encrypt stored passwords and can be enhanced with 'salt'

Hash functions convert text into unique, random sets of characters, a process that is computationally expensive and time-consuming to undo. Because hashed outputs for many common passwords are publicly listed, some sites use a salt—additional characters appended to a password—before hashing to produce an output that is not known. When entering a password, it is salted and hashed, then checked against the database for a matching hash before permitting login.

Passkeys, a new authentication method, aim to replace traditional passwords

Passkeys use cryptography keys to secure logins without passwords, resisting phishing and risks from data breaches. The FIDO Alliance developed passkeys as a combination of public and private keys for authentication.

Explaining how open source systems like Linux can be secure, despite their public source code

While no computer system is immune to all cyberattacks and malware, the transparency of open-source technology means many thousands of developers can review and oversee the underlying code powering the software on an ongoing basis. This increases the likelihood of catching and patching vulnerabilities more quickly than smaller groups of cybercriminals looking to exploit them.

Ethereum is a blockchain-powered operating system known for its cryptocurrency, ether

Ethereum's underlying blockchain allows developers to build decentralized applications (dApps) that leverage smart contracts to seamlessly run decentralized financial tools (crypto wallets, exchanges, marketplaces, and more), along with Web3 concepts like non-fungible tokens.

Decentralized applications are blockchain-based and run without a central authority

These apps use smart contracts to automatically execute functions, ensuring security, transparency, and censorship resistance. Built on platforms like Ethereum, Solana, and Binance Smart Chain, DApps power DeFi, NFTs, gaming, and social media, offering users control over their data and assets.

Ethereum is a blockchain-powered platform for building decentralized software and apps

Among crypto enthusiasts, ethereum is known for the cryptocurrency it uses to facilitate transactions: ether, or ETH. It's often compared to an app store. The underpinnings of ethereum's blockchain include dApps, which operate using automated scripts called "smart contracts."

What's the difference between QQ, WeChat, and Weixin?

Tencent owns QQ, Weixin, and WeChat—three separate apps serving different users. QQ launched in 1999 as a youth-focused messenger. Weixin (for China) and WeChat (international) are technically the same app, but split to comply with regional regulations, especially around data and payments.

Faraday cages protect enclosed objects by redirecting electrical currents

Constructed from conductive materials, the cage allows electrons to distribute themselves evenly throughout its surface and travel to ground, keeping the interior neutrally charged and preventing any internal electricity. The same principle blocks electromagnetic waves by redirecting the electric field component, preventing telecommunication signals from entering the apparatus.

Smart cities without strong cybersecurity can leave utilities extremely vulnerable

Insecure devices connected to the Internet of Things pose risks to the entire network, which cybercriminals can hijack to compromise infrastructure and private resident data. Poorly secured systems that become inoperable can undermine the promise of smart cities by worsening the quality of life.

During flights, cell phones can act like signal jammers as they search for service

When farther from cell towers, these devices expend more energy to emit more powerful signals, which can overwhelm any ground-based tower or radio telescope they fly past. Rather than protecting the flight, airplane mode conserves a cell phone's battery.

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.

WeChat has become China's primary news platform, due to expansive user base and legacy media's adoption of the platform.

Microchips in payment cards improve security by generating unique transaction codes

Magnetic strips store unchanging data that is easily cloned, but microchips act as miniature computers that encrypt sensitive data. They also resist fraud by creating data unique to each transaction, preventing duplication.

Watch a cybersecurity expert answers questions about hacking

From firewalls and VPNs to ransomware and viruses, IBM Distinguished Engineer Jeff Crume has seen many changes in cybersecurity during his 40 years of IT experience. In this video, he explores some of the most significant hacking events in history and provides advice on protecting yourself online.

Listen to an interview with Tencent's chief financial officer Arthur Wang to hear how the company is leveraging to AI to stay ahead of the technological curve.

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.

How the people behind spam text messages make money

If you've ever gotten a text message from a scammer—sometimes even just someone from an unknown number saying hello and calling you by the wrong name—you've probably wondered what they're trying to get out of you. This podcast answers that question. Hint: The answer has to do with cryptocurrency.

Privacy advocates warn menstrual cycle apps could put women at legal risk in certain states.

The WEF’s Edison Alliance connected more than 1 billion people to digital services

By 2024, the World Economic Forum-backed Edison Alliance had delivered digital connectivity and access to financial, healthcare, and education services to more than 1 billion people, using public-private partnerships across Africa, Asia, Latin America, and the US.

Are emojis real communication? And other questions for the experts

Emojis took off around 2009, after Apple's operating system for its defining iPhone became available in Japan. By 2012, a standardized set of emojis was released, and now seven in ten users feel a message without one of the 3,664 official emojis is lacking.

Credit monitoring services may oversell the benefits of dark web monitoring

Currently, technology exists to scrape and download data from webpages, which can then be analyzed to identify a user's information. However, scrapers cannot access or remove personal data from dark websites because they are often protected by paywalls, rendering monitoring ineffective beyond reporting publicly available data breaches.

Your device can become infected with malware by simply browsing the internet

During a drive-by download attack, security flaws in a program or operating system (e.g., Windows) used to access online content are exploited, and malicious code is downloaded—for example, when loading a hacked webpage—onto a user's device without their knowledge. Restricting internet browsing to safe sites and installing security updates helps prevent these attacks.

Davos becomes extremely heavily secured during the WEF

During the annual World Economic Forum in Davos, the city effectively turns into a fortress, guarded by thousands of Swiss army, police, and civil security personnel, with restricted airspace, drone surveillance, snipers, checkpoints, and round-the-clock patrols protecting global leaders.

Using cryptocurrency to turn traditional financial arrangements on their head

Cryptocurrency is poised to drastically change everything in the financial world, including financial arrangements. Decentralized finance makes it easier for virtually anyone to take advantage of financial markets without the need for a bank. However, there are new risks involved as well. Professor of Legal Studies and Business Ethics Kevin Werbach, an expert on Bitcoin and blockchains discusses it all in detail in The Conversation.

A brief guide to espionage

Spies have one of the most challenging and dangerous jobs in the world, risking their lives and legacy to extract secrets in the interest of their country. This in-depth explainer breaks down one of the profession's oft-ignored aspects: The...

Learn about the protocols that make navigating the internet possible

While TCP/IP sends data in packets to the correct destination and checks for errors, UDP omits such safety features to speed up data transfer for real-time communication and streaming. Software rules such as HTTP and HTTPS enable the transfer of content on the World Wide Web, while SMTP handles email messages between servers.

Contactless credit cards descend from a batteryless Cold War listening device

The same physics that let Soviet spies eavesdrop on the US ambassador in 1945 underlie contactless payment methods today. The device is a passive chip powered wirelessly by incoming radio waves.

The dark web can expose anonymous users to potentially dangerous environments

Browsing the dark web requires onion routing, which prevents visitors from being identified and the locations from which they connect from being traced. This has been useful to activists in environments affected by political oppression or instability. However, those unfamiliar with navigating the space may encounter malware and network attacks from denizen hackers.