Psiphon Guide

Contents:

• Section 1:How Psiphon Works


• Section 2:Getting & Installing Psiphon


• Section 3:Security & Trust


• Section 4:Connection Troubleshooting


• Section 5:Settings

The Internet
The Internet is a global network of billions of computers (or “routers”) which communicate with one another. These connected systems allow people to share (or “serve”) information to others. The Internet can be visualized as a web, with multiple routes and connections. If one connection is severed, the redundancy of the web infrastructure allows people to connect by finding another route. To get from one location to another, web traffic (messages sent on the Internet) make many hops. Traffic travels from router to router before arriving at their destination. In order to do this, specific networking and routing equipment is required. This is provided by Internet Service Providers (“ISPs”). ISPs allow Internet users to use their infrastructure, including ‘serving' content or providing access to other content that other ISPs ‘serve', usually for a fee.

Filtering & Censors
Filtering can occur at one or many points in the network, such as, the Internet backbone (often the international gateway), ISPs, institutions (such as companies or schools), and even on an individual's device (such as a phone or desktop computer).

Censors are actors implementing filtering at any level. They could be implementing filtering on behalf of another body, such as when an ISP filters content under orders of a government.

In order to block only certain types of traffic, the traffic must first be identifiable. When a system can differentiate between types of traffic passing through the network, it is potentially able to make decisions about that traffic. Filtering can be done through devices and programs that analyze and forbid certain types of traffic to pass. In some places technical blocking affects everyday Internet use.

Circumvention Tools
Psiphon is part of a category of technology known as circumvention tools. Circumvention tools are designed to bypass interceptive technical forms of blocking online. Circumvention tools usually work by either diverting web traffic so it avoids the machines that filter or by disguising the traffic to appear like traffic that is not subject to filtering. The Psiphon app does both. As filtering techniques become more sophisticated, circumvention tool providers must always update their technology and so methods and strategies are continually evolving.

Psiphon Traffic
As a censorship circumvention tool, the Psiphon app's primary objective is to establish a connection to the Internet. The Psiphon app attempts to connect to known Psiphon servers using various methods. Sometimes the Psiphon traffic is obfuscated, meaning that it is disguised to look like a different or less identifiable type of traffic.

Because it is encrypted, censors are unable to see the content of traffic passing through the tunnel. Censors may still attempt to block encrypted traffic based on other characteristics, such as communication protocols. Communication protocols are a set of rules used to route data and ensure it arrives at the intended location.

The Psiphon app has the ability to relay traffic through various communication protocols. It attempts to connect through different protocols until a connection is made. That way, if a censor is blocking one communication protocol, Psiphon is still able to connect by using another protocol.

To ensure that Psiphon's traffic is not identifiable, it is important to make it appear as generic and normal as possible to an external observer. The Psiphon app has the flexibility to adapt dynamically to changing network conditions by trying multiple strategies to connect, even when certain types of content or traffic are being filtered.

Psiphon Servers
Psiphon operates a large network of servers. Each Psiphon app needs to know some information about the servers it's trying to reach in order to make a connection. Newly downloaded Psiphon apps contain a short list of known servers within the network that it attempts to connect to. Censors may routinely try to block some Psiphon servers, therefore many need to be available.

The network is always changing. Psiphon continuously deploys new servers across numerous locations worldwide. The Psiphon app will receive updated information about how to access them. Over time, a single Psiphon app may eventually gain knowledge of hundreds of new Psiphon servers.

What makes Psiphon different than a VPN?
Virtual private networks (VPNs) are designed to allow users to send and receive data through a secure network tunnel. VPNs may even make use of very strong encryption, however, the majority of VPNs are not designed for circumvention purposes. VPNs are created for normal network conditions. VPN tools don't do anything special to disguise the nature of their traffic and communicate through one type of protocol. VPN traffic can be identified, so censors are able to block VPN traffic. Several countries are known to filter or degrade VPN connections, and others have been observed blocking VPNs in response to events such as elections or political protests. Today, modern censorship technology has made this kind of blocking relatively simple for censors.

Psiphon allows users to send and receive data through a secure network while also disguising the type of traffic being transmitted and even where it is coming from. Psiphon technology is designed to be resilient to censorship, including attempts to interfere with Psiphon network traffic directly. The numerous secure protocols used by Psiphon apps all appear different to censors, making it difficult to differentiate between Psiphon traffic and other types of Internet use. Even if one traffic type is filtered on a network, Psiphon is able to connect through another protocol. Psiphon works where many other tools do not.

How do I know I can trust Psiphon?
Psiphon is an open source application which means that its source code is available for anyone to review and comment on how the system is implemented and the underlying cryptographic technologies. Psiphon not only performs internal code reviews, but also has regular code audits and penetration tests performed by various external firms.

Psiphon encourages feedback and collects little to no personally identifiable information by default. For example, Psiphon does not require users create accounts and does not log client IP addresses. User-generated feedback is opt-in and best done through the app. This information is kept as anonymous as possible and does not include personal or account information.

More information about privacy and security can be found in Section 3: Security and Trust.

Section 2:Getting & Installing Psiphon

Psiphon technology is made available through multiple propagation strategies. If one method is blocked or unavailable in your country, there are other techniques you can use to obtain the app.
Psiphon is available on Android, iOS, and Windows.

Section 3:Security & Trust



Source Code
Psiphon is an open source project. Open source means that the source code is shared publicly and anyone is able to review and make suggestions. By allowing interested parties access to inspect the source code, open source applications can increase confidence in how applications are designed.

Find the source code and design documents here: https://psiphon.ca/open-source.html

Sustainability Model
Psiphon has always been free to users. It is our mission to reach as many people as possible, which in part means eliminating economic barriers.

Psiphon does not sell user data. So how does the company maintain a worldwide network?

Psiphon is able to sustain operational costs by maintaining a diversity of income sources,

• Winning international grants for technology development and network maintenance.
• Working with media partners to distribute content using branded Psiphon clients.
• Collaborating with ad networks in certain regions.
• Offering subscriptions for premium service in certain regions.

A software audit is the internal or external review of a software program to check its quality, progress, standards, and security. Internal code audits are performed regularly, and external code audits are generally triggered by major code changes such as the development of new features. External security audits are rigorous assessments conducted by third-party vendors to identify and record vulnerabilities and external threats in the source code. Audits help ensure the security of Psiphon users.

During an external code audit, Psiphon will work closely with the vendor. Any issues found are addressed based on importance, and then retested by the vendor. It is Psiphon's policy to make code reviews public. Find Psiphon's blog posts about these assessment events and the corresponding reports below.

External Security Audits
2014 - “Independent Security Assessment of Psiphon3” – Blog –“iSEC Partners Final Report-Psiphon3”– Report
2017 – “Psiphon Completes Another Third Party Security Review” – Blog – “Pentest-Report Psiphon06.-07.2017” – Report
2019 – “Pentest-Report Psiphon Apps & Server 10.2019”– Report

Privacy Policy
Psiphon values your privacy. Information about the data collected by Psiphon are detailed in our privacy policy: https://psiphon.ca/privacy






Settings on Windows