MobileActive.org

The first part of this article - Using HTTPS for Secure Mobile Browsing - describes how mobile browsing over HTTPS provides:

• encryption for you data during transmission
• verification of the identity of the remote site 

However, using HTTPS does not hide your identity. If you don’t want someone to know that you were accessing a particular  web site (or that you were accessing it at a particular time, such as when inflammatory content was posted), you need to anonymize your mobile browsing. Depending on how your network is set up, the site you are accessing may be able to see and keep a record of your IP address. Your network administrator, Internet Service Provider and/or Mobile Network Operator can see and keep records of the IP addresses of both your Internet-connected mobile device and the site you are accessing. IP addresses can nearly always be linked to a geographic location, whether a zip code or a city, and your ISP or mobile network provider can link your IP to your individual device.

Organisations and countries that block websites can do so by blocking communication to and from specific IP addresses. For this reason, anonymizing your browsing is also the first step to circumventing Internet censorship.

This article describes two tactics for anonymous browsing and censorship circumvention - using a proxy, and using a mobile version of the circumvention tool Tor. Both are used on cpmputers as well as mobile devices. Specific tools for mobile phones are described in the second part of the article.

Orbot is an anonymizing and circumvention app that connects Android phones to the Tor network. Developed by The Guardian Project, it is currently the only way to use Tor on a mobile phone.

Who should use it?

Orbot is for Android users who need to browse anonymously or circumvent blocked sites. It should work on both older and new model Android phones, and does not require a rooted phone (although there are some advantages to using it with one). Orbot is designed for proficient Android users.

How does it work?

Orbot sets up a connection to the Tor network and makes it available to apps through a local proxy.

Gibberbot is an instant messaging app for Android phones, developed by The Guardian Project. Gibberbot implements off-the-record messaging (OTR). Off-the-record messaging is a way to conduct an instant messaging conversation with the following attributes

• Encryption. An eavesdropper cannot read your messages
• Authentication. You can verify the identity of the person you’re chatting to - or at least of the account they are using.
• Deniability. It is not possible for a third party to prove that a particular user sent or received a particular message.
• Perfect forward secrecy. It is not possible for an attacker to decrypt a previous conversation, even if he/she obtains the encryption keys used to encrypt it.

Gibberbot can also use Orbot to route your chats over the Tor network. This prevents an observer from following the source and destination of your messages (effectively, from knowing you are chatting) and provides a way to circumvent web censorship that may involve chat servers being blocked.

Off-the-record messaging only works when both parties in the conversation are using it. This means both parties need to use Gibberbot, another mobile app, or chat software that supports it. Currently Gibberbot is the only option we know of for mobile phones. Off-the-record plugins are available for several PC chat programs, including Pidgin (Windows and Linux), Adium (Mac), Trillian (Windows) and Miranda (Windows).