A controversial European Union legislative proposal to scan citizens’ private messages in a bid to detect child sexual abuse material (CSAM) poses a risk to the future of internet security, Meredith Whittaker has warned in a public blog post Monday. She is the president of the non-profit foundation behind the encrypted end-to-end (E2EE) messaging application Signal.
“There is no way to implement such proposals in the context of end-to-end encrypted communications without fundamentally undermining the encryption and creating a dangerous vulnerability in the core infrastructure that would have global implications far beyond Europe,” he wrote.
The European Commission presented the initial proposal for mass scanning of private messaging apps to tackle the spread of CSAM online in May 2022. Since then, members of the European Parliament have been united in rejecting the approach. They also proposed an alternative route last fall that would have excluded E2EE applications from scanning. However, the European Council, the legislative body made up of representatives of member state governments, continues to push for strongly encrypted platforms to remain within the scope of the scanning law.
The most recent Council proposal, presented in May under the Belgian presidency, includes a requirement that “providers of interpersonal communications services” (also known as messaging applications) install and operate what the draft text describes as “technologies for upload supervision’. a text ed. Netzpolitik.
Article 10a, which contains the upload control plan, states that these technologies are expected to “detect, prior to transmission, the dissemination of known child sexual abuse material or new child sexual abuse material”.
Last month, Euractiv stated that the revised proposal would require users of E2EE messaging applications to consent to scanning for CSAM detection. Users who didn’t consent would be blocked from using features that involve sending visual content or URLs he also said — effectively degrading the messaging experience to basic text and audio.
Whittaker’s statement dismissed the council’s plan as an attempt to use “rhetorical games” to try to redefine client-side scanning, the controversial technology that security and privacy experts argue is incompatible with the strong encryption that supports confidential communications.
“[M]and mass scanning of private communications fundamentally undermines encryption. Perfect,” he emphasized. “Either this is through hacking, for example, the random number generation of an encryption algorithm, or by implementing a key escrow system, or by forcing communications to pass through a surveillance system before they are encrypted.”
“We can call it backdoor, frontdoor or ‘transshipment surveillance.’ But whatever you call it, each of these approaches creates a vulnerability that can be exploited by hackers and hostile nation states, removing the protection of unbreakable mathematics and replacing it with a high-value vulnerability.”
Also, hitting out at the revised Council proposal in a statement last month, Pirate Party MEP Patrick Breyer — who opposed the Commission’s controversial text-scanning plan from the start — warned: “The Belgian proposal means that the essence of extreme and previously initial conversation control proposal will be applied unchanged. Using messenger services solely for texting is not an option in the 21st century.”
The EU’s own data protection supervisor also expressed concern. Last year, he warned that the plan posed a direct threat to democratic values in a free and open society.
Meanwhile, pressure on governments to force E2EE applications to scan private messages is likely to come from law enforcement.
In April, European police chiefs issued a joint statement calling on platforms to design security systems in such a way that they can still detect illegal activity and report the content of messages to law enforcement. Their call for “technical solutions” to ensure “legitimate access” to encrypted data did not specify how platforms should achieve this inconvenience. But as we mentioned at the time, the lobby involved some form of client-side scanning. It therefore seems no coincidence that only a few weeks later the Council presented its proposal for “transhipment supervision”.
The draft text contains a few statements that seek to throw a proverbial fig leaf over the giant black hole of security and privacy that “moderate uploading” entails — including a line that says “subject to Article 10a, this Regulation does not prohibit or makes end-to-end encryption impossible’; as well as a claim that service providers will not be required to decrypt or provide access to E2EE data; a clause saying they should not introduce cybersecurity risks “for which it is not possible to take effective measures to mitigate that risk’; and another line stating that service providers should not be able to ‘infer the substance of the content of communications’.
“These are all nice sentiments, and they make the proposal a self-refuting paradox,” Whittaker told TechCrunch when we sought her response to these conditions. “Because what’s being proposed — screwing mandatory scanning into end-to-end encrypted communications — would undermine encryption and create a significant vulnerability.”
She contacted the Commission and the Belgian Presidency of the Council for a response to her concerns, but at press time none had responded.
EU lawmaking is typically a tripartite affair — so it remains to be seen where the block will ultimately end up in the CSAM scan. Once the Council agrees on its position, so-called trialogue talks begin with the Parliament and the Commission to seek a final compromise. But it is also worth noting that the composition of parliament has changed since MEPs agreed their negotiating mandate last year following the recent EU elections.
