A new taskforce will take “digital fingerprints” of millions of illegal images of child sexual abuse to prevent them from being shared online.

Analysts will assess, hash – create a unique code like a digital fingerprint – and grade two million images from the UK Government’s Child Abuse Image Database (CAID).

These comprise category A and B material – the most severe images and videos of child sexual abuse.

The taskforce, set up by the UK charity the Internet Watch Foundation (IWF), will then distribute the hashes to tech companies across the globe, allowing them to be blocked or removed if users try to share the images.

Not only will this absolutely vital work help to create a safer internet for us all, but it will help those victims whose sexual abuse imagery is shared time and time again, preventing their continued revictimisation and exploitation

It is funded through a grant from international child protection organisation Thorn.

The IWF said 2020 was the worst year on record for the amount of child sexual abuse material identified online and removed.

Its analysts sifted through 299,600 reports of potentially illegal material, up 15% from the previous year.

More than half (153,350) contained images or videos of children being sexually abused, a rise of 16% from the previous year.

Susie Hargreaves, IWF chief executive, called the move a “major step forward for internet safety”.

She said: “We’ve created this world-leading taskforce of highly trained analysts to help boost the global efforts to stop the distribution of child sexual abuse imagery online.

“Not only will this absolutely vital work help to create a safer internet for us all, but it will help those victims whose sexual abuse imagery is shared time and time again, preventing their continued revictimisation and exploitation.”

Safeguarding minister Victoria Atkins added: “This government is determined to ensure that we are doing everything in our power to prevent child sexual abuse online and the innovative use of technology is central to this.

“I am pleased that Child Abuse Image Database (CAID) data is helping the IWF to carry out this valuable work towards reducing access to child sexual abuse material online and thereby preventing the revictimisation of children.”

Julie Cordua, chief executive of Thorn, said: “IWF’s work to eliminate child sexual abuse images from the internet and end the cycle of revictimisation is critical and tremendously difficult.

“We are grateful for their continued commitment to this work and are humbled to support their efforts.”