Fingerprints from a million photos of abused children
The fingerprints produced one million images of child sexual abuse, the Internet Watch Foundation (IWF) said.
The UK charity, which is responsible for finding and removing such material online, said the fingerprints, known as hashes, would help businesses and police find copies of the photos.
It is hoped that by doing so, reuse of images will be avoided.
The images come from the government’s Child Abuse Image Database.
The database contains some of the most intense content appearing online, known as Category A and B material.
The hash is an identification code generated by an algorithm and serves as a fingerprint for each photo or video.
Many tech companies use hash lists to search their systems for child pornography, comparing photo hashes to lists created by organizations like the IWF.
However, the system has limitations. Changes to images can change the hash value, which means an image can escape detection, although the IWF insists the technology it uses allows an image to be resized, cropped or change its colors without changing the color of the image. chop
Encrypted images cannot be identified by hash lists.
Before making hashes, a human evaluator will determine which category falls under criminal material, according to UK law.
The charity is also producing accompanying metadata that explains the exact type of abuse committed against the child, which it hopes will also speed up enforcement action.
In a quote provided by the IWF, an image analyst said: “I have three children under the age of 11. The job has changed the way I think about them and the internet.
“I was amazed at the amount of material for a very young child. Some are five, six or seven years old. ”
Susie Hargreaves, executive director of the IWF, said in a statement that the nature of the material is such that its analysts are only allowed to work four-hour shifts, take regular breaks and have access to the best advice. and support.
The charity said it had helped remove an unprecedented amount of material.
In 2021, he said he took action to remove more than ever 252,000 web pages he said contained photos or videos of child sexual abuse victims.