Owen Campbell-Moore, a former Google intern who designed new features for Google Maps, has created Secretbook for Google Chrome, which uses JPEG Steganography to hide messages in Facebook photos. The message in the image can then only be decoded by a user who has downloaded the same extension and has the correct password.
Development of the extension took about a term’s worth of work, and was supervised by Computer Security lecturer Professor Andrew Ker.
Campbell-Moore, who is also technical director of Oxford Entrepreneurs which encourages students to launch start-ups, said the project was rooted in privacy concerns as the idea came from a “really creepy” US Air Force grant that was aiming to extract meaning from social media conversations.
Early reactions to the software have been positive. “It quickly spread with a few tech news outlets getting in contact to interview me about it. The privacy group Tor have also been in contact to ask if I would like to help bring browser-based steganography to their suite of privacy tools,” Campbell-Moore said.
The extension has enjoyed early success with 6984 downloads at the time of this article going to print
Although the extension is intended for Facebook, there are similarities between Campbell-Moore’s software and Twitter, as the hidden messages are limited to 140 characters in the same way that public tweets are.
However, it has caused controversy with the Daily Mail, which claimed last week that the software was the “first time that anyone has managed to work out how to hide messages in computer files”. The digital steganography technique has in fact been in existence for several years, with a short Google search producing papers on the topic dating as early as 2001.
Campbell-Moore has also rejected claims that the software could be used to aid terrorism. Writing on his website, he said that the aim was not to “provide total security”.
“This application is only suitable for casual users and is totally useless for serious applications such as terrorism since detection would not be difficult for organisations such as the NSA.”
Hidden online communication has already proved vital for people in oppressed regimes, particularly during the recent “Arab Spring” uprising. People in Egypt used the Tor service (which escapes the notice of authorities by using a volunteer network of servers) to communicate and organize themselves, and there is potential for this service to provide a similar function.
Other users had less sophisticated plans. “I think it has the potential to replace the Oxford University Compliments page as the university’s favourite secret message service,” commented one fresher.
The extension is available from the Chrome Web Store and can be downloaded here: https://chrome.google.com/webstore/detail/secretbook/plglafijddgpenmohgiemalpcfgjjbph?h