Skip to main content

This website is no longer being updated. Visit Dartmouth Now for all news published after June 7, 2010.

Dartmouth News
>  News Releases >   2009 >   December

Dartmouth researcher helps in halting the spread of child pornography

Dartmouth College Office of Public Affairs • Press Release
Posted 12/16/09 • Media Contact: Susan Knapp (603) 646-3661

  • Save & Share:
  • Bookmark on
  • Submit to Digg!
  • Share on Facebook
  • Bookmark on Google
  • Post to MySpace
  • Share with Reddit
  • Share with StumbleUpon
  • Post to Twitter
  • Email & Print:
  • E-mail this
  • Print this
PhotoDNA logo
Take part in the campaign on Dec. 16 and 17 by blogging, tweeting and posting to social networking sites your happiest memory of childhood and by using the campaign logo, found at

Hany Farid
Hany Farid (Photo by Joseph Mehling '69)

Microsoft and the National Center for Missing & Exploited Children (NCMEC) today announced the launch of PhotoDNA, their joint project to help find and remove images of child sexual exploitation from the Internet. Dartmouth computer scientist and digital forensics expert Hany Farid worked with Microsoft researchers to develop the PhotoDNA software that calculates distinct characteristics of a digital image and matches it to copies of that same image.

Microsoft has donated the software to NCMEC, which will use PhotoDNA to support their own operations and to enable online service providers and others to disrupt the online spread of child pornography.

“PhotoDNA is a powerful technology that will help combat online child pornography,” said Brad Smith, general counsel and senior vice president for Microsoft.

PhotoDNA technology works by creating a unique signature for a digital image, called a hash, that calculates the essential characteristics of the image. The hash is then compared to the signatures of other photos to reliably find matching signatures. Since 2003, NCMEC has reviewed and analyzed nearly 30 million photos and videos of child pornography. For 2010 alone, that number is projected to be 9 million.

“In collaboration with Microsoft Research, we have developed an efficient and powerful algorithm for image matching. The biggest challenge was to be able to efficiently and reliably match images while minimizing the false alarm rate,” said Farid, the director of the Neukom Institute for Computational Science at Dartmouth. “The scale of having to analyze billions and billions of images added a level of complexity not usually seen in the field of digital forensics.”

Established in 1984, NCMEC works to prevent child abduction and sexual exploitation, to help find missing children, and to assist victims, their families, and the professionals who serve them. Part of its work involves helping law enforcement and others reduce the distribution of child pornography over the Internet.

“The problem of child pornography has become epidemic; NCMEC’s Child Victim Identification Program reviews and assesses 250,000 child pornography images and videos per week, and the victims are getting younger and the abuse more brutal. To stop this tragedy, we need companies like Microsoft and technology like PhotoDNA to help limit the availability of the pictures and play a role in helping protect and prevent further distribution of these damaging images,” said Ernie Allen, president and CEO of the National Center for Missing & Exploited Children.

NCMEC will make PhotoDNA available to law enforcement agencies, online service providers, and other partners to disrupt the ability of predators to use the Internet to exploit children or traffic these graphic images of child pornography.

“It is exciting and rewarding to be part of developing technology that holds the promise to help the young victims of child pornography and their families”, said Farid.

Microsoft and NCMEC are also issuing a call to consumers, policy-makers, and the online services industry to come together to help stamp out child pornography. Consumers can take part in the campaign for A Childhood for Every Child on Dec. 16 and 17 by blogging, tweeting and posting to social networking sites their happiest memory of childhood and by using the campaign logo, found at

Dartmouth has television (satellite uplink) and radio (ISDN) studios available for domestic and international live and taped interviews. For more information, call 603-646-3661 or see our Radio, Television capability webpage.

Recent Headlines from Dartmouth News:

Last Updated: 1/5/10