Image Hash List
Stop anyone from uploading, downloading, viewing or hosting images of child sexual abuse with our Image Hash List.
IWF Image Hash List video
What is the Hash List?
We turn child sexual abuse images into unique codes (hashes) – think of it as a digital fingerprint. We do this using Microsoft PhotoDNA. With our list, you'll be able to automatically match known images before they appear on your services. You'll also be able to remove illegal images already on your services. You'll receive an updated list every day.
Why do I need it?
If people can upload, download, view or host images on your services, you probably need our Image Hash List.
You'll be able to stop:
- the upload of a child sexual abuse image on your system
- the sharing of an image through your services
- the use of your hosting services by a child sexual abuse website.
So using our Image Hash List will:
- make your network safer
- protect your customers
- save your employees time and distress
- protect the victims from repeat victimisation.
How does it work?
We’ve teamed up with Microsoft to make it easy for companies to use our Image Hash List, with a cloud-based automated system. It’s impossible for most companies to manually scan every image that’s uploaded onto their platforms. The IWF Image Hash List does this for you in the background – without affecting your users’ experience.
It means you can compare anything from a single image to the millions of images uploaded through your platforms daily. The Image Hash list can flag illegal images already in your systems and prevent new ones being uploaded.
Corporate Vice President, Microsoft EMEA, Michel Van Der Bel says: “The impact of IWF’s work has been profound. They have made great progress, but there is more to be done. This is a journey. Microsoft was delighted to be able to employ the technology of our cloud based service to support IWF’s Image Hash List. It’s great work and we are very happy to be involved.”
IWF Deputy CEO, Fred Langford says: “The collaboration with Microsoft and our access to the police database makes this development unparalleled globally. For us, this development could revolutionise the way we work and give peace of mind to the thousands of children, whose images have been shared again and again. We currently have more than 200,000 unique hashes on the list but we’re looking at potentially millions.”
Enhanced quality checks
Two of our expert analysts check each child sexual abuse image. These enhanced quality checks mean each image is categorised accurately before it reaches your systems. International companies trust the IWF Hash List and use it with legal confidence. We add thousands of images every week.
You can download the list via an API, avoiding the need for additional, external hardware - making access to our list even more secure.
Our image hashes are categorised for international use. So whether your services focus on a single country or a multi-national platform, we tailor the list to what you need.
Better than traditional hashes
We help you keep up with the criminals. Unlike traditional hashing technology, an image can be resized, cropped or colours changed and our hashes will still find a match to the original image.
How do we find illegal images?
The images on our List come from:
- public reports
- our analysts actively searching for them - we're the only hotline doing this
- the UK Home Office’s Child Abuse Image Database (including images that aren’t yet online).
Who can use it?
IWF Members can use the IWF Image Hash List under licence. Companies that will benefit include:
- filtering providers
- hosting or file sharing services
- social media and chat services
- data centres.
Two versions available
We provide both PhotoDNA and MD5 versions of the hashes.
Get in touch
To talk about how our Image Hash List could help you, email email@example.com or call +44 (0)1223 20 30 30.
“The impact of IWF’s work has been profound. They have made great progress, but there is more to be done. This is a journey."
"Microsoft was delighted to be able to employ the technology of our cloud based service to support IWF’s Image Hash List. It’s great work and we are very happy to be involved.”Michel Van Der Bel, Corporate Vice President, Microsoft EMEA