Thread by @shashj

I wrote this week on the latest skirmishing in the crypto wars. End-to-end encryption has conquered the world. Governments continue to push back in defence of lawful intercept. But the debate around technical solutions has changed little in years.
economist.com/international/…

A few sources for this piece. In 2018 & 2021 a pair of GCHQ officials proposed various solutions for reconciling gov't interception with end-to-end encryption. The first piece proposed that govts could be added secretly to particular communications:
lawfaremedia.org/article/princi…

The second proposed various types of "client-side scanning"—automatically comparing content on a device to a stored library of illegal material—as a way of detecting child sexual abuse material on social media sites without intercepting content in transit. arxiv.org/abs/2207.09506

Cryptographers argued that the first idea—adding gov't to chats as a secret participant, or a 'ghost protocol'—had significant downsides, because it'd require pushing code changes to all users. blog.cryptographyengineering.com/2018/12/17/on-…

In a paper in 2021, many prominent cryptographers also pushed back against client-side scanning, arguing that it would introduce vulnerabilities, that it could be dangerously expanded in scope or exploited by attackers.
arxiv.org/abs/2110.07450

.@AlecMuffett has a good (long) primer on end-to-end encryption and why it's so hard to devise means to lawfully access content that does not in effect undermine encryption as a whole. alecmuffett.com/alecm/e2e-prim…

This paper looks at the encryption debate in India, which has demanded that message services identify the "originator" of a message. WhatsApp has said that would undermine encryption and has threatened to withdraw from India. carnegieindia.org/research/2023/…

In 2021 @ciaranmartinoxf gave a brilliant speech on these - increasingly vitriolic - debates around lawful access v encryption. "Some experts say, in effect, that the government is arguing not against a policy decision, but against mathematics." bsg.ox.ac.uk/sites/default/…

Governments are still asking tech companies to limit or modify the use of encryption. In April 32 European police chiefs said: "end-to-end encryption is being rolled out in a way that undermines their ability to investigate crime and keep the public safe." nationalcrimeagency.gov.uk/news/european-…

In April also a coalition of 15 law enforcement agencies including Interpol, FBI, NCA and others said much the same. They asked tech companies to "make tangible steps towards possible solutions that we know exist."
nationalcrimeagency.gov.uk/statement-on-e…

The European Union continues to explore a very ambitious client-side scanning scheme ("Chat Control"), though there is no consensus on it yet. A note on this was presented to ambassadors as recently as yesterday.
euractiv.com/section/law-en…

Matthew Green, a cryptographer, laid out a critique of the EU scheme below.

https://x.com/matthew_d_green/status/1634252397919739921