> How does this affect browser modifications and extensions?
> Web Environment Integrity attests the legitimacy of the underlying hardware and software stack, it does not restrict the indicated application’s functionality: E.g. if the browser allows extensions, the user may use extensions; if a browser is modified, the modified browser can still request Web Environment Integrity attestation.
Then what's the point? I can make modified bot browser that commits ad fraud as long as I don't use a rooted Android phone?
I don't believe they're being honest with how this will be used. We need to legally regulate remote attestation.
> As new browsers are introduced, they would need to demonstrate to attesters (a relatively small group) that they pass the bar, but they wouldn't need to convince all the websites in the world.
It speaks for itself. Horrid.
Another use case is multiparty computation. Three people wish to compare some values without a risk that anyone will see the combined data. TC can do this with tractable compute overhead, unlike purely cryptographic techniques.
Observe what this means for P2P applications. A major difficulty in building them is that peers can't trust each other, so you have to rely on complex and unintuitive algorithms (e.g. block chains) or duplication of work (e.g. SETI@Home) or benign dictators (e.g. Tor) to try and stop cheating. With TC peers can attest to each other and form a network with known behavior, meaning devs can add features rather than spend all their time designing around complicated attacks.
These uses require you have a computer that you do trust which can audit the remote server before uploading data to it. But you can compile and/or run that program on your laptop or smartphone, the verification process is easy.
But exactly because TC is general it doesn't distinguish based on who owns the machine. It doesn't see your PC as morally superior to a remote server, they're all just computers. So yes, in theory a remote server could demand you run something locally and then do a HW remote attestation for it. In practice though this never happens anymore outside of games consoles (as far as I'm aware), because most consumer devices don't have the right hardware for it, and even if they did you can't do much hardware interaction inside attested code.
The issue client-side is that if a single vendor or TPM design is compromised, threat actors have ample motive, resources and ability to exploit this compromised hardware, whilst everyone else has few choices, such as dumping at great expensve some more e-waste. And critically, you as a user are blocked by your acceptance of TPM attestation technology from discovering attacks and auditing your own system security, as you ceded control of your own systems. Instead, your systems are controlled by a few technology companies that have a proven terrible track record of fulfilling their alleged intent of keeping your systems and data secure. And why should they care if it doesn't lead to a higher profit at the end of the year?
[1] https://github.com/binarly-io/SupplyChainAttacks/blob/main/M...
[2] https://github.com/binarly-io/SupplyChainAttacks/blob/main/M...
[3] https://github.com/binarly-io/SupplyChainAttacks/blob/main/L...
[4] >>30565985