Internet censorship circumvention

Internet censorship circumvention is the use of various methods and tools to bypass internet censorship. Commonly used tools include Lantern and Psiphon, which bypass multiple safeguard types. Some methods use alternate DNS servers, false addresses or address lookup systems to evade less sophisticated blocking tools. However, such methods do not work if censors block the IP address of restricted domains in addition to DNS, rendering the bypass ineffective. Other tools tunnel network traffic to proxies in jurisdictions without censorship. Through pluggable transports, traffic obscuration, website mirrors, or archive sites, copies of sites can be accessed in areas under internet censorship.

An arms race has developed between censors and developers of circumvention software, resulting in more sophisticated blocking techniques by censors and the development of harder-to-detect tools by tool developers. Estimates of adoption of circumvention tools are disputed, but are widely understood to be in the tens of millions of monthly active users. Barriers to adoption include usability issues, difficulty finding reliable and trustworthy information about circumvention, lack of desire to access censored content, and risks from breaking the law.