A new mobile application for Apple devices called Wickr lets people exchange files and messages without leaving digital traces that could be examined by law enforcement or cyberspies.
Wickr, released on Wednesday, addresses the raft of privacy concerns that arise when a person sends a sensitive message: email providers, ISPs, mobile phone companies and social networking sites all retain detailed records of activity on their networks.
Those records could be requested by law enforcement or accessed potentially by other people with ill intentions. San Francisco-based Wickr offers a system that is based on heavy encryption, no log files and a robust data destruction system to ensure data stays secret forever.
Senders of a message or photo can set a self-destruct time for the data ranging from a few seconds to six days in the free version of Wickr. As soon as the recipient who has Wickr installed opens the message, the countdown begins.
"No matter what can do, you cannot stop the clock," said Robert Statica, an information technology professor at New Jersey Institute of Technology, who cofounded Wickr with Nico Sell, Christopher Howell and Kara Coppa.
Wickr makes it hard for a person to take a screenshot of a photo or video: the recipient has to hold down a "button" on the screen, and if a fingertip moves more than a couple of pixels, the data disappears, Statica said. To take a screenshot on an iPhone, a person must push the power button and home button at the same time.
Once the time period has expired, Wickr writes over the photo or file in the device's memory with random data. This is important since computers and other devices don't immediately erase data that has been tagged as garbage. Using special computer forensics software, the data can often be recovered.
"The operating system reports that the file has been deleted but in fact the file remains on the hard drive on the device until it is overwritten," Statica said.
Before transmission, text and photos are scrambled on the device using 256-bit AES (Advanced Encryption Standard) encryption. The encryption keys are also encrypted and only used once before being discarded. Wickr doesn't have access to any of the encryption keys used for securing data.
Even a person's user name is stored by Wickr as a cryptographic cipher. "We don't know who you are," Statica said.
As an added security measure, data is sent using SSL (Secure Sockets Layer), an encrypted security protocol. Only encrypted data passes through Wickr's servers, and log files are deleted. Statica said no information is retained by Wickr about what files users are sending and to whom.
The only real way to see something sent to a Wickr user would be to steal the person's phone. Even then, five wrong attempts at the password will cause Wickr to erase itself.
Wickr also tackles the privacy problems concerning metadata, or information about a file or photograph that is often included as part of the default settings of an application. Metadata can reveal more information than perhaps the person who took the photo or sent the file really wants to share.
Cameras, for example, will often include data such as GPS information, times and dates. Word processing programs can note who has looked or edited a document and the filer server where it has been stored. Wickr scrubs files of metadata.
So far, Wickr has been poked and prodded by well-known computer security pros, said cofounder Nico Sell. "I've had a number of my hacker friends break it," she said. "They fixed a lot of things."
But Wickr is ready to go: A free version is available Apple's App Store, and an Android application under development. A paid-for premium version of Wickr is in the works that will let users buy specific features, such as extending the time period before data is deleted. "We are always planning to do more," Sell said.
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