The Three Layers of the Internet
The internet can be classified into three layers based on accessibility:
- Surface Web: The portion indexed by search engines like Google, accessible to anyone
- Deep Web: Content not indexed by search engines - email inboxes, membership sites, databases, and similar resources
- Dark Web: A highly anonymous layer that can only be accessed using specialized software
The deep web and dark web are often confused, but they are distinct. The vast majority of the deep web consists of legitimate content.
How the Dark Web Works Technically
Access to the dark web primarily relies on the Tor (The Onion Router) network.
Tor routes communications through multiple nodes (relay servers), adding a layer of encryption at each stage to make it extremely difficult to link the source and destination of a communication. This multi-layered encryption is the origin of the term "onion routing." For more details on the Tor browser, see our dedicated article.
Sites on the dark web use the special ".onion" domain and cannot be accessed with a standard browser. Both site operators and visitors can communicate without knowing each other's IP addresses.
What Happens on the Dark Web
Illegal Activity
Much of the attention the dark web receives stems from its role as a marketplace for illegal transactions. Stolen personal data and credit card information are bought and sold, malware is traded, and illicit drugs are distributed.
Legitimate Uses
On the other hand, the dark web also serves legitimate purposes. Journalists and activists in countries with restricted freedom of speech use it to bypass censorship and share information. Whistleblowing platforms and privacy-focused communication tools also operate on the dark web.
Has Your Information Been Leaked to the Dark Web
Personal information exposed through a data breach is sometimes bought and sold on the dark web. There are ways to check whether your own information has been leaked.
- Check for email address leaks at Have I Been Pwned (haveibeenpwned.com)
- Use the dark web monitoring feature of your password manager
- Take advantage of your credit card company's fraud monitoring service
If a leak is confirmed, follow the steps outlined in our data breach response guide and act without delay. Familiarizing yourself with phishing detection techniques will also help you guard against secondary attacks that exploit leaked information.
It is also worth using IP Check-san to review your own IP address and connection details, so that you know where you stand on anonymity and security.
Common Misconceptions About the Dark Web
Several misconceptions about the dark web are widely held:
- "Accessing the dark web is illegal" - Most countries have no provision that prohibits using Tor or reaching the dark web in itself. What is punished is the transactions and criminal acts carried out there
- "The dark web is completely anonymous" - While Tor provides a high degree of anonymity, it is not absolute. Operational mistakes such as signing in to one of your own non-anonymous accounts, or vulnerabilities in software, can narrow your identity down. In addition, when you use Tor to visit an ordinary site rather than an ".onion" address, the contents of traffic that is not protected by HTTPS can be read at the point where it exits the route
- "The dark web is enormous" - In reality, it is very small compared to the surface web
Related Glossary Terms
Frequently Asked Questions
Is it illegal just to access the dark web?
In Japan there is no provision that prohibits accessing the dark web in itself. However, buying illegal goods, or downloading and possessing illegally uploaded content, can be a crime depending on the material. Viewing it for a legitimate purpose such as security research or journalism is not in itself a crime.
Can I check whether my data has leaked to the dark web?
Services such as Have I Been Pwned and dark web monitoring tools can tell you whether your email addresses or passwords have been exposed. Some password managers include dark web monitoring as a built-in feature.