Tor
Tor (previously an acronym for The Onion Router) is free software for enabling online anonymity and resisting censorship. Tor directs Internet traffic through a free, worldwide, volunteer network consisting of more than five thousand relays to conceal a user's location or usage from anyone conducting network surveillance or traffic analysis.
Using Tor makes it more difficult for Internet activity to be traced back to the user: this includes "visits to Web sites, online posts, instant messages, and other communication forms". Tor's use is intended to protect the personal privacy of users, as well as their freedom and ability to conduct confidential communication by keeping their Internet activities from being monitored. An extract of a Top Secret appraisal by the National Security Agency (NSA) characterized Tor as "the King of high secure, low latency Internet anonymity" with "no contenders for the throne in waiting".
Security
Tor uses "Tor circuit". That is something like that: Your computer > Random Tor node 1 > Random Tor node 2 > Random Tor exitnode > Internet
Tor node is a computer running Tor. Tor exitnode is similar to Tor node, but it connects with Internet or Darknet. If some website on Internet tries to detect IP adress, it will detect Tor exitnode's IP adress. When you send your data to Tor circuit, they are encrypted with 3 layers and then sent: Your computer - 3 layers of encryption > Tor node 1 - 2 layers of encryption > Tor node 2 - 1 layer of encryption > Tor exitnode - raw data. This is why Tor is unsafe. For Tor exitnode has raw data and if you don't use HTTPS protocol, Tor exitnode can see your passwords or anything what it wants. It can edit site you are looking at or display malware instead of it. This is called man-in-the-middle attack.
The other situation is in Tor Hidden Services because there is everything end-to-end encrypted and there are no exitnodes. Tor's security depends on what you use Tor for. If you use Tor for accessing clearnet, Tor isn't safe for you but if you use Tor for accessing Tor Hidden Services then it's relatively safe for you.
See also
- TorBox
- Torbook
- WOT forums - Some WOT forums softwares designed to work inside I2P can also work inside Tor network
- Password.i2p is accessible via I2P, Tor and Clearnet