Whittaker said such a system would turn everyone’s phone into a “mass surveillance device that phones home to tech corporations and governments and private entities”. In 2021 Apple was forced to pause its client-side scanning plans, which would have involved the company scanning user photos before they are uploaded to its image-sharing service.

Whittaker also criticised a system called client-side scanning, where images are scanned before being encrypted. End-to-end encryption ensures that only the sender and recipient of a message can view its content. Signal, which has been downloaded more than 100m times on Google’s app store, is operated by a US-based nonprofit organisation and is widely used by activists and journalists, as well as some intelligence services. She said: “Encryption is either protecting everyone or it is broken for everyone.”

Whittaker told the BBC it was “magical thinking” to believe there can be privacy “but only for the good guys”, adding that the bill was an example of this thinking. Privacy advocates warn the bill could force encrypted messaging services such as Signal, WhatsApp and Apple’s iMessage to monitor users’ messages and create vulnerabilities in their platforms that could be exploited by rogue actors and governments.

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