4 ms·

What's the impact of this?

by kzrdude 2y ago

RockRobotRock 2y ago
May help break DRM? But not sure
- ronsor 2y ago
  PC Blu-ray players all require SGX. Now that's permanently broken.
  - lxgr 2y ago
    Apparently that's been on the way out for a while now: https://news.ycombinator.com/item?id=32442894 https://news.ycombinator.com/item?id=32442894 Now I'm curious, thouyh: Have there really never been any software Blu-ray players supporting AMD?
    - toast0 2y ago
      Blu-ray is fine, it's Ultra Blu-Ray (aka Blu-Ray 4k) that needs SGX for officially licensed playback. No AMD support there. But non licensed play back is fine.
  - brokenmachine 2y ago
    I think it was already broken? 37C3 - Full AACSess: Exposing and Exploiting AACSv2 Uhd Drm for Your Viewing Pleasure https://www.youtube.com/watch?v=SEBuiecLZGg https://www.youtube.com/watch?v=SEBuiecLZGg
gojomo 2y ago
Some of Signal's designs for contact privacy, including in the new usernames feature, rely on trust in SGX. If anyone (including Signal) can pretend to be a secure SGX environment, you're back to trusting Signal's personnel/operations, rather than Intel/SGX, for some of the metadata/contact privacy they've historically touted. More info (2020): https://medium.com/@maniacbolts/signal-increases-their-reliance-on-sgx-f46378f336d3 https://medium.com/@maniacbolts/signal-increases-their-relia...
- eklitzke 2y ago
  Just to expand on this, since it wasn't originally clear to me from reading your post, the contact privacy feature is about using SGX enclaves for the purpose of populating your known contacts on Signal. When you log into Signal for the first time your phone locally has all of your known contacts, and the Signal app wants to know which of these contacts already have Signal accounts. The secure enclave is a mechanism where you publish your entire contact list from your phone to the Signal servers, then they can send back the subset of those contacts that actually have Signal accounts. The point of the enclave is that this is all done in a way where Signal can't see what contacts you sent them, nor can they determine which contacts were matched and sent back to you.
- ein0p 2y ago
  [flagged]
  - anaisbetts 2y ago
    [flagged]
    - randunel 2y ago
      [flagged]
      - eviks 2y ago
        You can't prove the reverse
      - nurple 2y ago
        Agreed, it's a fact that any US corporation will not be allowed to run lest they give the gov access to the data they hold (cref lavabit). I've never really understood the trust given to Signal in the tech community when a hard identity is required (phone #) and it immediately asks you to send your whole contact list to them on first run. We know from Snowden that metadata about who is communicating with whom, and when, is one of their most valuable data streams. While signal may not be able to turn over the contents of your messages, they absolutely retain a rich stream of metadata.
inhumantsar 2y ago
it's used quite a bit in finance for things like transaction signing. the keys used to create signatures only ever exist within the SGX enclave, similar to how yubikeys and HSMs do the same thing. compromising SGX wouldn't suddenly open up all of these transactions to exploitation though, since the attacker would need (presumably root) access to the machine and the keys could always be rolled. I'm no expert but I suspect it would mean urgent firmware updates for anyone relying on SGX

What's the impact of this?

RockRobotRock 2y ago

May help break DRM? But not sure

ronsor 2y ago
PC Blu-ray players all require SGX. Now that's permanently broken.
- lxgr 2y ago
  Apparently that's been on the way out for a while now: https://news.ycombinator.com/item?id=32442894 https://news.ycombinator.com/item?id=32442894 Now I'm curious, thouyh: Have there really never been any software Blu-ray players supporting AMD?
  - toast0 2y ago
    Blu-ray is fine, it's Ultra Blu-Ray (aka Blu-Ray 4k) that needs SGX for officially licensed playback. No AMD support there. But non licensed play back is fine.
- brokenmachine 2y ago
  I think it was already broken? 37C3 - Full AACSess: Exposing and Exploiting AACSv2 Uhd Drm for Your Viewing Pleasure https://www.youtube.com/watch?v=SEBuiecLZGg https://www.youtube.com/watch?v=SEBuiecLZGg

gojomo 2y ago

Some of Signal's designs for contact privacy, including in the new usernames feature, rely on trust in SGX. If anyone (including Signal) can pretend to be a secure SGX environment, you're back to trusting Signal's personnel/operations, rather than Intel/SGX, for some of the metadata/contact privacy they've historically touted. More info (2020): https://medium.com/@maniacbolts/signal-increases-their-reliance-on-sgx-f46378f336d3 https://medium.com/@maniacbolts/signal-increases-their-relia...

eklitzke 2y ago
Just to expand on this, since it wasn't originally clear to me from reading your post, the contact privacy feature is about using SGX enclaves for the purpose of populating your known contacts on Signal. When you log into Signal for the first time your phone locally has all of your known contacts, and the Signal app wants to know which of these contacts already have Signal accounts. The secure enclave is a mechanism where you publish your entire contact list from your phone to the Signal servers, then they can send back the subset of those contacts that actually have Signal accounts. The point of the enclave is that this is all done in a way where Signal can't see what contacts you sent them, nor can they determine which contacts were matched and sent back to you.
ein0p 2y ago
[flagged]
- anaisbetts 2y ago
  [flagged]
  - randunel 2y ago
    [flagged]
    - eviks 2y ago
      You can't prove the reverse
    - nurple 2y ago
      Agreed, it's a fact that any US corporation will not be allowed to run lest they give the gov access to the data they hold (cref lavabit). I've never really understood the trust given to Signal in the tech community when a hard identity is required (phone #) and it immediately asks you to send your whole contact list to them on first run. We know from Snowden that metadata about who is communicating with whom, and when, is one of their most valuable data streams. While signal may not be able to turn over the contents of your messages, they absolutely retain a rich stream of metadata.

inhumantsar 2y ago

it's used quite a bit in finance for things like transaction signing. the keys used to create signatures only ever exist within the SGX enclave, similar to how yubikeys and HSMs do the same thing. compromising SGX wouldn't suddenly open up all of these transactions to exploitation though, since the attacker would need (presumably root) access to the machine and the keys could always be rolled. I'm no expert but I suspect it would mean urgent firmware updates for anyone relying on SGX