My understanding is that there will be a new authority, Ofcom, that will regulate the community of messaging application vendors. One of there powers will be to

My understanding is that there will be a new authority, Ofcom, that will regulate the community of messaging application vendors. One of there powers will be to enforce the scanning of messages for CSAM or terrorism related content and Ofcom can force them to use an "accredited" service to scan for the illegal content. I suspect the scanning of this content will be handled solely by accredited services, these likely will have close communication with one or more government entities who supply information on what content is or is not illegal. At this point there isn't really end-to-end encryption anymore: every message will be submitted to one (or more) accredited services. Even if it's encrypted, each message now has the government's blessed service as a recipient. It's important to remember that we're talking about text messages as well as images, a system that compares only hashes will not be sufficient. The bit about terrorism related information is also worrisome as we know the list of what is and isn't terrorism related is a very political debate. https://techcrunch.com/2022/07/06/uk-osb-csam-scanning/ https://techcrunch.com/2022/07/06/uk-osb-csam-scanning/