Microsoft Helps Root Out Child Exploitation Images Online
Even resizing or compressing images doesn't stop Microsoft Research-designed PhotoDNA from spotting illegal images.
A team of computer scientists from Microsoft and Dartmouth College, along with the National Center for Missing & Exploited Children (NCMEC), have come up with a way to automate the detection and location of child pornography on the Internet.
Microsoft (NASDAQ: MSFT), which initially developed the technology, is donating what it calls PhotoDNA to NCMEC to help it root out images of children being sexually abused by predators -- and to get them off the Web.
Representatives of all three bodies made the announcement Wednesday in a conference call with members of the press.
Scientists at the software giant's Microsoft Research (MSR) division first created PhotoDNA, which underwent later refinement with help from Hany Farid, a digital forensics expert and professor of computer science at Dartmouth.
The concept behind PhotoDNA is that digital images have their own identifying signatures that can be determined via what's known as "robust hashing" -- a mathematical technique for generating a unique digital signature for every image.
The weakness in using most hashing schemes on images is that the slightest modification to an image changes its hash or signature.
Researchers found a way to retain and track the original signature, even if an image is manipulated, such as by resizing, cropping, or compressing it.
"PhotoDNA will enable us to identify and disseminate information to help locate these images," NCMEC President and CEO Ernie Allen said.
The software is both fast and accurate, the parties claim. According to Dartmouth's Farid, the false-positive rate for PhotoDNA's technology is less than one in a billion images, and its detection accuracy is "upwards of 98 percent."
The need, the parties said, is urgent.
"The victims are getting younger and the acts are getting more violent," Farid added.
Added Smith, "It's not enough to stop the perpetrators. The real point is getting the images off the Internet."
However, while PhotoDNA will help aid NCMEC in its goals, the parties agreed that the real need is to get it into the hands of ISPs. The parties have had a pilot project for PhotoDNA running for some time, and that will be expanded before it's offered to the Internet community.
"We are moving to implement PhotoDNA starting in the public areas of Bing [Microsoft's search engine] and various Windows Live properties," Microsoft General Counsel Brad Smith said.
To that end, PhotoDNA's creators are currently negotiating with approximately 60 major ISPs.
"Our expectation is we will make it available to ISPs within a matter of months," Allen said. "We think this is going to have incredible impact."
Stuart Johnston is a contributing writer to InternetNews.com, based in Bellevue, Wash.