The Internet Watch Foundation (IWF) said that digital fingerprints of onemillion pictures of child sexual abuse had been created. The British charity, which is responsible for finding and deleting such materials on the Internet, pointed out that these fingerprints, called hash values, will help companies and police find copies of these images.
It is hoped that by doing so, law enforcement departments can prevent the reuse of images. These images are from the government's image database on child abuse. It is reported that the database contains some of the most extreme content on the Internet - the so-called class A and class B materials.
The hash value is an identification code generated by the algorithm as the fingerprint of each image or video.
Many technology companies use hash value lists to search for child abuse materials in their systems - by comparing the hash values of images with lists created by organizations such as IWF.
However, the system also has its limitations. Modifications to the image may change the hash value, which means that the image may escape detection - although IWF insists that the technology it uses means that the image can be resized, cropped or changed in color without changing the hash value.
Encrypted images cannot be identified by hash value list.
Record numbers
Before creating a hash value, according to British law, human assessors will find out what kind of criminal material belongs to.
In addition, the charity has produced accompanying metadata to explain the exact nature of the abuse that occurs to children, which it hopes will also speed up law enforcement.
In a passage provided by IWF, an image analyst said: "I have three children aged 11 and below. This work has changed the way I think about them and the Internet. I am surprised that there are so many materials about young children. Some of them are only five, six or seven years old."
Susie Hargreaves, CEO of IWF, pointed out in a statement that the nature of these materials determines that its analysts are only allowed to work for four hours, take regular breaks and receive the best consultation and support.
The charity said it had helped remove an unprecedented amount of material. In 2021, it said it had taken action and deleted 252000 web pages. It confirmed that these pages contained images or videos of child sexual abuse - more than before.