Onion routing disguises internet traffic in layers resembling a nesting doll

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.

The internet explained at five levels of difficulty, from protocols to internet flattening

Resembling a roadway with traffic laws that all cars must follow, the internet is the hardware that connects a source to a destination, and these connections must follow specific software rules. Although data had to travel through about 10 networks to reach a destination in the past, data centers increasingly consolidate traffic, just as a highway does for cars, to improve data speeds.

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 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.

An explanation of TCP/IP, which helps transmit data across the internet like a club sandwich

The system consists of several layers—application, transport, internet, and network—each responsible for specific tasks. These include interacting with a web browser, checking for errors, sending packets of data across various networks to avoid congestion on their way to a destination address, and managing the transmission of information across hardware, such as an Ethernet cable.

Explore metrics on the Tor network, the infrastructure of the dark web

While internet traffic within the network is concealed, public, nonsensitive data can be used to estimate the number of active users, the number of relay servers, network performance speed and reliability, etc. Researchers can use this data to indirectly identify political upheavals or censorship campaigns worldwide, such as the Arab Spring.

Instead of .com or similar, web addresses on the dark web end in 'd.onion'

Since the latest version of the onion routing protocol, dark web domain names consist of a random set of 56 alphanumeric characters followed by .onion (e.g., propublica.org → p53lf57qovyuvwsc6xnrppyply3vtqm7l6pcobkmyqsiofyeznfu5uqd.onion). The last character is always "d" due to the encryption algorithm's requirements.

A 2020 study suggests just 6.7% of Tor network users visit sites on the dark web

It did not distinguish between visits to malicious sites and traffic to legitimate institutions with .onion domains, such as the BBC or Buzzfeed, and thus claimed that 6.7% of anonymized users engage in nefarious activity. The low percentage still highlights that most users of the technology underlying the dark web do not use it to browse the hidden portion of the internet.

As of April 2022, a million people access Facebook on the dark web monthly

While those using an anonymized web browser, such as Tor, have been able to access the social network's .onion site since 2014, the announcement marks a major milestone by the tech giant, which has worked to ensure its users can bypass restrictions by various governments and continue visiting the site.

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.

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.

The 500 subsea cables that run the internet

Subsea cables carry the majority of data sent across the globe on the internet. An estimated 552 such cables—with more in development—lay on the ocean floor, their thickness similar to a garden hose, made up of optic fibers covered in copper.

A look at nodes and miners in managing bitcoin transactions

Each time a transaction involving bitcoin is carried out, the information must be relayed and recorded onto the currency’s blockchain. Multiple steps are involved, including the passage of the transaction to various nodes and miners who comprise multiple layers of verification and validation. See an illustrated guide to how these two crucial features of bitcoin processing work here.

Google data centers possess six layers of security

Property boundaries, such as anti-climb fencing, overlapping cameras, vehicle crash barriers, and circulating patrols, are coupled with lobby iris scans and ID and badge checks. The security operations center monitors individuals throughout their visit, including the less than 1% of Google users who ever receive permission to visit the data center floor.

Explore content on the dark web safely with the Ahmia search engine, which has provided activists with digital addresses to anonymously send files to media outlets.

Money laundering is a three-step process: placement, layering, and integration

"Placement" occurs when dirty money is introduced into the financial system. Then "layering" happens when the money is moved around to disguise where it actually came from. Finally, the money is placed in other assets or investments in a step called integration.

Learn how governments around the world restrict internet access for their citizens

Various countries around the world, including China, Russia, and Iran, control their local DNS infrastructure, allowing them to block access to online content by preventing the internet "phone book" from finding the IP addresses for specific URLs. Government-controlled internet service providers can also cut off access entirely or throttle specific traffic.

The dark web cannot be stumbled upon by accident

Many pages on the dark web are not publicly broadcast and are available only to relevant parties on a need-to-know basis. Although some online directories list the URLs for these webpages, connecting to them still requires specialized software, as these pages block connections from traditional web browsers such as Chrome.

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.

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.

Learn about the construction of the undersea fiber optic cables carrying internet data

Over 750,000 miles of fiber-optic cables run along the seafloor, serving as a freeway for the Internet's data. Despite subsea cable projects costing hundreds of millions of dollars, depending on the length of the cable, it remains the fastest and most cost-effective way to send information.

The dark web makes up about 0.01% of all the data on the internet

The surface web (5%-10%) consists of indexed sites—those traditional search engines have visited and stored so users can discover them via web search. The remaining 90%-95% makes up the deep web, which is not indexed and includes email and banking portals that require login credentials. The dark web is unindexed and requires anonymizing software to visit.

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.

As of 2025, an estimated $3.2B in annual revenue flows through dark web platforms

The untraceable cryptocurrency Monero is used in about 60% of transactions across more than 37 active marketplaces that sell copyrighted materials, private information, and phishing kits—tools that help bad actors more easily create fake sites to steal users' data—for financial fraud.

Trudging through the dark web to expose child abuse

A computer expert who created a system to track down sources of revenge porn and an investigative journalist joined forces to investigate digital abuse. Their investigations focused on so-called clear nets, websites that make up the web most users surf. Then, they turned their investigation toward the dark web, where they found a child abuse website with more than 1 million registered users.

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.

Watch an ethical hacker provide a tour of the dark web

Cybersecurity researcher John Hammond explores the effectiveness of a dark web search engine, leaks from ransomware group data breaches, and a categorized index of dark web links, including some that are alleged to host malware. Many dark web sites are no longer active or host scams to fool unsuspecting visitors.

Explore a searchable map of underwater cables carrying internet traffic worldwide

The Submarine Cable Map provides users with data from TeleGeography's Transport Networks Research Service on individual submarine cables, including cable owners, suppliers, URLs, landing points, lengths, and notes of interest.

With a core consisting of a glass fiber roughly the width of human hair, fiber-optic cables transmit digital information via flashes of light that reflect within the glass.

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.

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.

How the Domain Name System works and how it provides a directory for the internet

DNS translates domain names, such as join1440.com, into numerical IP addresses, such as 192.0.2.1, which computer systems use to determine what content a user is looking for across the World Wide Web, making navigation easier for the vast majority of users. Web outages can occur if the DNS servers making these translations become inaccessible.

The deep web accounts for 90-95% of the internet

Within the Deep Web is the small and hidden Dark Web, which is inaccessible via traditional web browsers. Dark Web inhabitants are anonymous and use special software to access encrypted websites that can assist with both free speech and criminal activity.

Trick a large language model into revealing secret passwords over multiple rounds, each with increasing safeguards.

OSINT: How hackers find their marks

What is OSINT? How do hackers gather intel about targets? Just how much can they learn about you? Learn more as we dig in to the world of OSINT.

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.

Anonymous' war against Russia

Anonymous has been waging a cyber war on Russia for invading Ukraine. CNBC takes a look at how effective the collective’s six main strategies have been.

Ads follow you around the internet through technology called 'cookies.'

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.

Watch a video that visualizes what really happens inside a credit card network when you make a purchase.

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.

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.

View the ecosystem of global services, organizations, and agencies behind the internet

Through an open, transparent, and collaborative model built on open standards development and shared global ownership, the internet is kept freely accessible amid evolving international policies. Key organizations, such as IANA, which allocates IP addresses and fulfills administrative functions for the Domain Name System, function as non-profit organizations.

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.

Visualizing the growth of botnets

Botnets are a network of computers that have been infected with a variant of malware that coordinates and leverages them for automated mass attacks such as data theft and crashing servers. This interactive map highlights where botnets have been located between 2014-2020.

What is Net Neutrality?

ISPs shouldn’t be able to block some sorts of data and prioritize others. Here’s what to know about the struggle to treat all information on the internet the same.

The origin of shortest-path algorithms and how they became optimized for navigation apps

In 1956, Dutch programmer Edsger Dijkstra spent about 20 minutes developing an algorithm to demonstrate how computers could quickly determine the shortest route between Rotterdam and Groningen. Since then, modified versions of Dijkstra's formulation comprise the processing backbone of systems such as Google Maps and Apple Maps.

As of 2025, the internet is entering its fourth phase, with three more to go

Since the inception of the internet as a tool for connecting teams of researchers, technological and infrastructure advancements have progressively increased connectivity. Connections between computers, mobile devices, all devices, and now AI agents will be succeeded by an internet that integrates perception and the senses toward an eventual quantum internet.

The Bomb-proof, Cold War-era New York data center inspiring spy movies

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.

Earth's inner structure is a dynamic system of layers in constant, slow motion

From the crust to the core, each of Earth's layers—some solid, some liquid—plays a role in generating its magnetic field, moving tectonic plates, and cycling matter. These details are determined through modeling since humans have only drilled 12 kilometers underground.