What is the IWF Hash List?

We have a growing list of hashes of child sexual abuse imagery. A hash is a unique code – like a digital fingerprint of an image. Using PhotoDNA and MD5 technology, we create hashes of the child sexual abuse content we see and we add these to our Hash List.

Why is this Hash List important?

Three trained IWF experts have looked at each image and assessed it before a hashed image is included on the list. We use these hashes to help us find duplicate images of child sexual abuse.

How does this help technology companies?

When technology companies use our Hash List, it helps them to stop the sharing, storage and even the upload of child sexual abuse content. To make it easy for technology companies to use, each hashed image is graded according to international standards so companies have confidence in the data we provide them.

You can read the analysis of our hash data here.

IWF URL List Previous
Non-photographic imagery list Next