Illustrative speech bubble and lock representing end to end encryption (E2EE)

Preventing the upload of child sexual abuse imagery in end-to-end encrypted environments

What is end-to-end encryption (E2EE)?

Standard encryption is widely used across the internet for all kinds of services, including banking apps, health records and messaging services. It is used to keep private information private. End-to-end encryption (E2EE) goes a step further, meaning only the sender and intended recipient hold the keys needed to ‘unlock’ or decrypt the message.

Messaging services have become a major channel for the distribution of CSAM


Over recent years, an increasing number of digital platforms have implemented E2EE and are no longer deploying proactive detection. This makes it harder to detect criminal content, like CSAM (child sexual abuse material), by securely scanning imagery against lists of known illegal content.

Icon showing E2EE message and padlock

Upload prevention is a technically feasible method that is proven to detect known CSAM in E2EE environments

IWF’s explainer delves into how platforms can prevent the upload of CSAM in E2EE environments in a privacy preserving way. Upload prevention is a method that works and is already being used by companies to check for other types of content. It is time these safety checks also extended to CSAM. Governments must require companies to implement the upload prevention method on their E2EE services and reduce the risk of known CSAM being sent and shared on their services. Implementing upload prevention will be a crucial step in preventing offenders from sharing known CSAM on E2EE messaging.

Icon of person in message and padlock E2EE

All platforms have a duty to make sure they are not safe havens for criminals to target children and share child sexual abuse material  


Services that adopt end-to-end encryption must also adopt upload prevention, ensuring that known CSAM is detected and blocked before it can be shared. In doing so, platforms can uphold both the security of private communications and the fundamental rights of victims and survivors.
 

New guidance for parents and carers as AI-manipulated images of children become a growing concern

New guidance for parents and carers as AI-manipulated images of children become a growing concern

With AI-generated sexual abuse imagery increasing every year, the IWF and NCA call on families to understand the risks of sharing children's photos online.

3 July 2026 News
KIDZONET joins the Internet Watch Foundation to strengthen child protection across digital networks

KIDZONET joins the Internet Watch Foundation to strengthen child protection across digital networks

By working with the IWF, KIDZONET is reinforcing its commitment to disrupting the spread of child sexual abuse material online.

29 June 2026 News
Survivor voice central to IWF annual report launch discussions in Brussels

Survivor voice central to IWF annual report launch discussions in Brussels

Crucial perspectives from a survivor and a senior analyst at the front line of the fight against child sexual abuse material anchored the EU launch of the Internet Watch Foundation’s 2025 Annual Data & Insights Report.

11 June 2026 News
On-device nudity detection has ‘powerful role to play’ in fight against child sexual abuse online

On-device nudity detection has ‘powerful role to play’ in fight against child sexual abuse online

IWF backs government move requiring tech companies to urgently implement nudity detection and blocking on children’s devices.

8 June 2026 News
IWF partnership strengthens CaseScan’s ability to swiftly detect child sexual abuse content

IWF partnership strengthens CaseScan’s ability to swiftly detect child sexual abuse content

CaseScan, a specialist technology company supporting child protection investigations and digital safety efforts, has joined the Internet Watch Foundation (IWF) as a Member.

1 June 2026 News
Immaterialism partners with IWF to boost fight to stop spread of child sexual abuse material online

Immaterialism partners with IWF to boost fight to stop spread of child sexual abuse material online

Immaterialism will be among the first registrars to receive the Internet Watch Foundation (IWF)’s dedicated Registrar Alerts.

27 April 2026 News