By the end of the year, Twitter hopes to set in place the new system

Jul 22, 2013 11:26 GMT  ·  By

Twitter joins the companies that fight against child abuse images being posted online. The company said it would introduce a tagging system to prevent such images to end up on its service in order to protect its millions of users from such content.

Twitter’s system is said to use an industry standard developed by Microsoft, named “PhotoDNA,” as soon as the end of the year, The Guardian reports.

The decision comes among another effort regarding child safety, namely a new rule set down by the United Kingdom regarding the default blocking of sites with adult content by Internet providers, but also on search engines.

Microsoft and Facebook are already using PhotoDNA to monitor the images posted on the social network, Skydrive and Bing.

Basically, the system produces a “hash,” which is a single number generated from the binary data of the photo or video, as well as some biometric information in the picture. The method works even if the image is resized or altered so all similar pictures can be wiped in one go.

"One of the most exciting things that we're working on is implementing PhotoDNA. It's really fantastic that we're making progress on getting that in place. And it's good that others in the industry are working on it, or on implementing it, because this is one of those areas which is not about competition, it's about co-operation. We're trying to keep the user safe," says Del Harvey senior director of Twitter’s Trust and Safety team.

He, of course, references the millions of users that post pictures each day, out of the nearly 2 billion tweets every five days.

Before he joined Twitter, Harvey worked on preventing child abuse.

Google announced recently that it had been using a “hashing” technology since 2008 in a system that’s compatible with Microsoft’s PhotoDNA.