Five leading online service providers will jointly build a database of child-pornography images and develop other tools to help network operators and law enforcement better prevent distribution of the images.
The companies pledged $1 million among them Tuesday to set up a technology coalition as part of the National Center for Missing and Exploited Children. They aim to create the database by year's end, though many details remain unsettled.
Ernie Allen, the chief executive of the missing children's center, noted that the Internet companies already possess many technologies to help protect users from threats such as viruses and e-mail "phishing" scams.
"There's nothing more insidious and inappropriate" than child pornography, he said.
The announcement comes as the U.S. government is pressuring service providers to do more to help combat child pornography.
Top law enforcement officials have told Internet companies they must retain customer records longer to help in such cases and have suggested seeking legislation to require it.
AOL chief counsel John Ryan said the coalition was partly a response to Attorney General Alberto R. Gonzales' April speech identifying increases in child-porn cases and chiding the Internet industry for not doing more about them.
The creation of the technology coalition does not directly address the preservation of records but could demonstrate the industry's willingness to cooperate.
Plans call for the missing children's center to collect known child-porn images and create a unique mathematical signature for each one based on a common formula. Each participating company would scan its users' images for matches.
AOL, for instance, plans to check e-mail attachments that are already being scanned for viruses. If child porn is detected, AOL would refer the case to the missing-children's center for further investigation, as service providers are required to do under federal law.
Each company will set its own procedures on how it uses the database, but executives say the partnership will let companies exchange their best ideas — ultimately developing tools for preventing child-porn distribution instead of simply catching violations.
"When we pool together all our collective know-how and technical tools, we hope to come up with something more comprehensive along the lines of preventative" measures, said Tim Cranton, Microsoft's director of Internet safety enforcement programs.
Ryan said that although AOL will initially focus on scanning e-mail attachments, the goal is to ultimately develop techniques for checking other distribution techniques as well, such as instant messaging or Web uploads.
Representatives will begin meeting next month to evaluate their technologies, determining, for instance, whether cropping an image would change its signature and hinder comparisons. Also to be discussed are ways to ensure that customers' privacy is protected. Authorities still would need subpoenas to get identifying information on violators.
The companies involved said they are talking with other service providers about joining. But companies that do not participate still are required by law to report any suspected child-porn images, and many already have their own techniques for monitoring and identifying them.