What is Onion Service?

What is Onion Service?

An onion service, formerly known as a hidden service, refers to a specific type of service that is only accessible through specialized software programs constructed with the aim of ensuring privacy and anonymity for users. The most common instances of such services are websites that are hosted on .onion domains. These particular domains are designed for anonymity and can only be accessed via the Tor Browser, a specialized internet browser built to interact with these unique domains.

However, onion services are not limited to websites alone. A wide array of other services also exist in this hidden or anonymous format. Some examples of these include FTP (File Transfer Protocol), SSH (Secure Shell), Telnet, SMTP (Simple Mail Transfer Protocol), and the Jabber/XMPP messaging service. Each of these services is hosted through the Tor anonymity network, adding an extra layer of security and privacy. To access these onion services, users need to have specific software installed that can interpret the communication protocol of the service. This means that even if a user has the Tor Browser, they may not be able to access certain onion services. This is because the Tor Browser may not be equipped to understand the specific protocols that these services operate under.

To illustrate, if a user wants to connect to an FTP service that is hosted as an onion service, they would need an FTP client, like FileZilla. However, just having the client is not enough. The user would also need to configure the FTP client in a way that it can route requests to the Tor network. This is necessary because it is via the Tor network that the connection to the onion service is established. Without this configuration, the user would not be able to connect to the onion service even with an FTP client like FileZilla.