psiphon: 破墙软件，即将发布，

What is psiphon?
psiphon is a censorship circumvention solution that allows users to access blocked sites in countries where the Internet is censored. psiphon turns a regular home computer into a personal, encrypted server capable of retrieving and displaying web pages anywhere
When will psiphon be released?
psiphon software will be released on December 1st, 2006, with subsequent releases to be provided as new features are added over time.
Who will use psiphon?
psiphon operates through networks of trust. There are psiphon providers who install and administer a psiphon server (psiphonode) in an uncensored country, and psiphon users (psiphonites) who login and access the server from a country that censors the Internet.
What are psiphonodes, psiphonode administrators and psiphonites??
A psiphonode is a psiphon server that is operated by an administrator residing in an uncensored country (this is an integration of ‘psiphon‘ and ‘Node‘). The psiphonode administrator is responsible for creating and managing user accounts and running the psiphon server. A psiphonite is a psiphon user, residing within a jurisdiction that blocks arbitrary web sites, and utilizes a psiphonode residing in an uncensored jurisdiction.
How does psiphon work?
psiphon acts as a "web proxy" for authenticated psiphonites, retrieving requested web pages and displaying them in a user‘s browser. psiphon uses a secure, encrypted connection to receive web requests from the psiphonite to the psiphonode who then transports the results back to the psiphonite. There is no connection between the psiphonite and the requested website, as psiphon transparently proxies the request through the psiphonode‘s computer allowing the psiphonite to browse blocked websites seamlessly.
How do psiphonites connect to psiphon?
psiphonites go to their psiphonodes‘ machine using a unique web address. The first page displayed is the user login. The psiphonite must login with a valid username and password, given to them by the psiphonode administrator. After authentication, the psiphon server displays a toolbar at the top of the page where the psiphonite can then enter a website to browse. When using psiphon, the psiphonite does not have to install any software or change any browser settings.
What do you mean, "the user does not have to install any software"?
After a successful login to the psiphon server, the user enters the website address they would like to visit, and psiphon takes care of the rest. With a regular Internet browser, the psiphonite simply logs in and requests and views the website entered in the psiphon toolbar. No software is installed on the end user‘s machine.
How do users find out about psiphon and how is psiphon distributed?
Anyone who wants to become a psiphon provider and is located in an uncensored country will be able to download the psiphon software from the psiphon website. After installation, the psiphonode administrator sends a unique web address to people in need that he or she personally knows and trusts in censored countries.
Even if the psiphon website is blocked it does not affect psiphon‘s distribution model. psiphon is completely decentralized; each psiphonode is independent of all others. The distribution of access to personal psiphon servers is based on social networks. Each psiphonode administrator grows his/her private network based on social relations of trust.
What is a social network?
A social network is a structure of nodes - usually individuals or organizations - that have ties between them, such as families or groups of friends or colleagues. psiphon leverages social networks as the discovery mechanism. The psiphonode administrator and the psiphonite(s) have a trust relationship and the web address is known only to these trusted people. Each network of psiphonode/psiphonites chooses how to grow the network. It can be small and extremely private or large and relatively semi-private. It depends on the specific context and needs of the psiphonites.
Can psiphon be blocked?
With publicly accessible circumvention systems one must assume that the censors can also discover and subsequently block access to these systems. The difference with psiphon - a personal system - is that the web address is only sent to a few, trusted, people. In that way, the censors cannot easily find and block the location of the psiphon server.
What happens when the psiphon provider‘s computer is turned off?
When a psiphon provider‘s computer is down or off the psiphon users will no longer have access to psiphon. psiphon users will need to wait until the psiphon provider‘s computer is back up and running again.
psiphon will inform psiphon providers if their network information changes (e.g. after rebooting the computer). When network information changes, psiphon providers will need to supply their psiphon users with the new psiphon web-address.
Note for advanced users: Future releases of psiphon will contain functionality that allows for optional redundancy. In the same way that psiphon providers and users extend their network based on social relations of trust, psiphon providers in a social network can arrange peering agreements to act as a backup psiphon server for each other‘s users.
Is psiphon anonymous?
psiphon is not an anonymous software program. psiphon users are not anonymous from the psiphon provider. Although traffic between the psiphon user and psiphon provider is encrypted, psiphon providers can potentially monitor everything that is done by the psiphon users they host.
Note: Do not use psiphon for anything you do not want the psiphon provider to be able to see.
When psiphon users visit websites through the psiphon server their identity and location is hidden from the web-site.
Note for advanced users: To maximize protection against the discovery of the psiphon user‘s true IP address, all scripting languages, such as JavaScript and ActiveX, should be turned off in the user‘s browser.
Can a psiphon user be monitored by their government or Internet Service Provider (ISP)?
Yes, your government and/or ISP can always monitor which web sites you visit.
When you use psiphon, your government and/or ISP can only see that you connected to another computer, not the sites you visit. psiphon makes it difficult for anyone to determine that you are using psiphon
Am I safe using psiphon?
psiphon encryption provides strong protection against electronic eavesdropping. However, there is a known attack that attempts to trick users into accepting a forged certificate (see ‘Man-in-the-middle attack‘ below). If psiphonites follow instructions provided, regarding certificate fingerprint validation, this attack can be averted.
Secondly, using an encrypted connection to a home computer in another country may indicate to a government that a censored-bypassing system is being used.
Note: Bypassing censorship may violate law. Serious thought should be given to the risks involved and potential consequences.
What languages will psiphon be in?
Having multi-lingual interfaces for psiphon is a priority. The intention is for psiphon to be available in as many languages as possible. More information will be provided closer to psiphon‘s release date.
What operating systems will psiphon work on?
Windows, Linux (Mac conversion still underway)
How much does psiphon cost?
psiphon is free.
Is psiphon open source?
Yes. psiphon will be released under GPL open source license.
Can I access my email with psiphon?
psiphon is designed to provide safe, secure web browsing for users in censored countries. Most webmail can be accessed through psiphon.
Can I use instant messenger/chat, VOIP, Skype with psiphon?
No. psiphon is intended for Internet website browsing only. But, most web-based tools and services are available through psiphon.
Can I edit my blog with psiphon?
psiphon is intended for Internet website browsing only. Most Web-based tool and services are available through psiphon. Therefore psiphon can be used to edit most blogs.
When does beta testing begin?
Beta testing to the public will begin in the summer of 2006.
For advanced users:
Can my use of psiphon be detected?
From a technical perspective traffic between the psiphonode and the psiphonite is identical to normal HTTPS (encrypted) traffic. Although many sites only use HTTPS during the login process many sites, such as email providers and banking services, use HTTPS for extended periods of time, as does psiphon. The differences are that psiphon uses self-signed certificates and connections to home computers, rather than signed certificates and domain names. However, unless the attacker has the private psiphon URL it cannot be easily determined that psiphon is being used.
The key to detecting psiphon is infiltration of the psiphon administrator‘s social network.
Is psiphon susceptible to a Man-In-The-Middle-Attack (MITM)?
While a MITM attack can be attempted against any specific HTTPS connection, manual key fingerprint identification is integral to the proper use of psiphon. Anytime a psiphon URL is sent to a user the certificate fingerprint is also included. The psiphon user only needs to verify the fingerprint one time.
The key to a MITM attack is to trick the user into accepting a fake certificate. If the user properly verifies the certificate fingerprint on the first connection to psiphon the MITM attack can be defended.
What options are available for advanced users (customization)?
A psiphonode administrator will be able to customize the port number that the server runs on as well as the content that appears at the "index" page. An HTTPS connection can actually run on any port number although 443 is the default. Some ISPs block particular ports and some users may choose to run psiphon on a non-standard port.
The "index" page is the page that appears when one connects directly to the server‘s root path - not the psiphon URL. An attacker monitoring a users connection, at an ISP for example, can directly connect to any IP addresses that the user connects to in order to see what content is there. Each psiphon URL has a unique file path, which is encrypted so this attacker cannot connect to the psiphon login page, only to the IP address. If the provider modifies the "index" page the attacker will see completely innocuous content if they connect to psiphon.
Who is behind psiphon?
psiphon is part of the CiviSec Project run by the Citizen Lab at the Munk Centre for International Studies at the University of Toronto. The CiviSec Project is funded by the Open Society Institute.
The Director of the Citizen Lab is Prof. Ronald J. Deibert.
The graphic design for psiphon is produced by Agent 5 Design.