Psiphon is a tool built to evade Internet censorship. The app is currently maintained by Psiphon Inc. although it was originally developed by Citizen Lab for the OpenNet Initiative (ONI). Available for Windows and Android, Psiphon uses SSH, VPN and HTTP Proxy secure technologies to bypass filters imposed by governments on Internet users.
Psiphon operates on a number of servers which you connect to via SSH or VPN. Each client contains a database of these servers. This database is updated constantly so if the older ones get blocked you’ll be able to connect to new ones. The integrity of the system is kept via digital signatures that prove its authenticity.
Psiphon also have certificates embedded to verity its authenticity. Clients for Windows and Android are available, and it is available in several languages, the majority of which are from countries where the Internet is censored. If this is your first time to use the app, there’s a FAQ which explains what the software is, what it is for and how to resolve common problems.
Psiphon is an anti-censorship application and it does the job well. What makes it very effective is the fact that it uses several transport systems so if one is blocked you just switch to another. For instance, if your attempt to use SSH is blocked, you can try PVN or SSH+.
Apart from bypassing censors, Psiphon also provides full privacy and confidentiality, as it conceals your Internet activities from your service provider. Because the server and connection is encrypted, your ISP won’t be able to determine what you’re doing.