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I'm kind of confused by AMD's and Intel's response. I thought both companies were building technology that allows datacenter operators to prove to their custome
by fweimer 1y ago
I'm kind of confused by AMD's and Intel's response. I thought both companies were building technology that allows datacenter operators to prove to their customers that they do not have access to data processed on the machines, despite having physical access to them. If that's out of scope, what is the purpose of these technologies?
- Harvesterify 1y agoSecurity theater, mostly.
- hbbio 1y agoTEEs don't work, period. FHE does (ok, it's much slower for now).
- LPisGood 1y agoWhy do you say TEEs don’t work at all?
- treyd 1y agoTEEs, as they're marketed, requires a true black box. True black boxes do not exist, as a property of the rules of our universe. You can ALWAYS break them, it's just a matter of cost, even assuming they're perfectly designed and have no design/implementation flaws. And they're often not perfectly designed, sometimes requiring no physical hardware tampering.
- rossjudson 1y agoThe point of security efforts is to make an attacker's life harder, not to construct perfect defenses (because there's no such thing, as you've noted). TEEs make attacker's lives harder. Unless you can find a way to make your interposer invisible and undetectable, the value is limited.
- fpoling 1y agoQuantum mechanics with its non-copy property implies that a true black box can be created.
- davemp 1y agoI’ve always assumed it’s a long term goal for total DRM
- heavyset_go 1y agoRemote attestation of our personal devices, including computers, the apps we run and the media we play on them. The server side also has to be secure for the lock-in to be effective.
- mike_hearn 1y agoFor Intel it's not out of scope, it's just that the specific CPUs they attacked fall into a tech mid-point in which Intel temporarily descoped bus interposers from the threat model to pivot in the market towards encrypting much larger memory spaces. From Alder Lake onwards they fixed the issue in a different way from classic "client SGX" which had the most cryptographically robust protections and is not vulnerable to this attack, but which imposed higher memory access costs that scaled poorly as size of protected RAM grew. For AMD they just haven't invested as much as Intel and it's indeed out of scope for them. The tech still isn't useless though, there are some kinds of attacks that it blocks.
- catchcatchcatch 1y ago[dead]
- saurik 1y agoYou've mentioned multiple times on this thread that Intel has a fix for this in their latest CPUs, but I haven't seen that called out anywhere else... I've only seen the idea that latest CPUs use DDR5 (which also is true of AMD SEV-SNP's EPYC 9005) and so happen to be too difficult (for now) for either the teams of Battering RAM or WireTap?
- mike_hearn 1y agoLook at their advisory. It says: > Use of cryptographic integrity protection mode of Intel® Total Memory Encryption - Multi-Key (Intel® TME-MK) can provide additional protection against alias-based attacks, such as those outlined in the Battering RAM paper. This feature is available on 5th Generation Intel® Xeon® processors (formerly codenamed Emerald Rapids) and Intel® Xeon® 6 processor family with P-cores (formerly codenamed Granite Rapids). I guess it depends how you interpret "additional protection". But look at the website. They say none of their attacks work on TDX. Only "Scalable SGX". However, TME-MK is indeed still vulnerable to other kinds of attacks like replay attacks. It isn't going to be as strong as the original SGX design. Unfortunately, as I explain in my other comment, the original SGX design is a kind of theoretical ideal that expects people to make software redesign efforts to benefit from it and the market just has no stomach for much extra spending on security or privacy right now.