Signal’s president, Meredith Whittaker, has strongly criticized a revised European Union proposal that seeks to surveil encrypted communications under the guise of “upload moderation.” This proposal, part of the Chat Control law, is ostensibly aimed at combating child exploitation material but has raised significant concerns about privacy and encryption integrity.

The EU Commission first introduced the Chat Control law in mid-2022, pushing for rules that would effectively require messaging apps to create a backdoor to access end-to-end encrypted messages. In November last year, the EU Parliament committee voted against the mass screening of encrypted telecommunications. However, a revised draft has now emerged, proposing "upload moderation" as an alternative method for mass scanning to address online child sexual abuse material.

On June 17, Whittaker issued a statement denouncing the "upload moderation" tactic, asserting it is merely a rebranded effort to weaken encryption. She emphasized that while the term “client-side scanning” has been replaced, the fundamental threat to encryption remains. Whittaker argued that this new label does not alleviate the risks because the scanning occurs before encryption, thereby exposing private chats to potential exploitation by hackers and hostile nations.

The Importance of Encryption

Whittaker highlighted the critical role of end-to-end encryption in safeguarding privacy in an era marked by unprecedented state and corporate surveillance. She insisted that encryption must be preserved to ensure the security of private communications. The revised Chat Control law proposal would mandate telecommunication service operators to implement "upload moderation" techniques to combat child exploitation material. This would involve scanning private chats against a state-curated database using artificial intelligence models to detect inappropriate content.

Concerns Over the Proposal

Whittaker described the rebranding efforts as ineffective, stating that encryption experts are not deceived by the change in terminology. She urged legislators to abandon these "word games" and recognize that any form of mass scanning fundamentally undermines encryption. According to Whittaker, regardless of the method—whether termed a backdoor, front door, or upload moderation—the result is a vulnerability that can be exploited, thus compromising the security provided by encryption.

“We can call it a backdoor, a front door, or ‘upload moderation.’ But whatever we call it, each one of these approaches creates a vulnerability that can be exploited by hackers and hostile nation states, removing the protection of unbreakable math and putting in its place a high-value vulnerability,” Whittaker stated. “Let’s be very clear, again: mandating mass scanning of private communications fundamentally undermines encryption. Full stop.”

Signal's Commitment to Encryption

Signal employs elliptic curve cryptography to support its end-to-end encryption for messaging, audio, and video services. The company has been a staunch advocate for strong encryption, even hinting at withdrawing from the UK market following the passage of the Online Safety Bill, which could allow authorities to bypass end-to-end encryption.

Broader Implications for Privacy and Security

The controversy surrounding the revised Chat Control law underscores a broader debate on encryption and privacy. Signal’s firm stance highlights the tension between efforts to combat child exploitation and the need to protect privacy through robust encryption. This debate is particularly pertinent as other messaging platforms and privacy advocates watch closely.

Signal’s embrace of encryption extends to its support for cryptocurrencies, which rely on encryption to secure transactions. In March 2021, Signal began accepting donations in Bitcoin, Ether, and ten other cryptocurrencies to support the Signal Technology Foundation, reflecting its commitment to encryption and privacy.

In conclusion, the revised Chat Control law proposal has sparked significant controversy, with Signal’s president leading the criticism. The debate highlights the ongoing tension between security measures and privacy rights, emphasizing the importance of robust encryption in safeguarding personal communications. As discussions continue, the outcome will have far-reaching implications for the future of encrypted communications and privacy protection in the digital age.