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Intel deprecates SGX on Core series processors

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Re: Intel deprecates SGX on Core series processors

#111

Post by phire »

paconbork wrote: post #103
phire wrote: post #98

Earlier quoted context omitted.

I have seen a deployed altcoin built on SGX. Can't remember the name or if it was even successful. In my opinion, it's a huge risk. With a regular blockchain, the fact that someone might maliciously be running the wrong code is baked into the design, and the security model has to handle it. With SGX, you are relying on Intel's security model to make sure everyone is running the same code. If SGX is ever broken (which…

Are you thinking of Secret Network? If I remember correctly, they use SGX for transaction privacy (transactions are encrypted with a key that is only known to enclaves). An SGX break I think would just make it a generic proof of stake network but maybe the way they ended up doing smart contracts is different?

Yeah, I think secret network is the one I'm remembering. It's been a long time since I was paying attention to the cryptocurrency space.

My consern is that it hasn't been tested as a generic proof of stake network and there is a risk that it might not degrade as expected.

It also means the blockchain can't be independently verified. If someone was to exploit it in a way that gave themselves extra coins, then nobody would ever know because all evidence is hidden inside the secure enclave.

How big is the risk? I'm not sure. I just suspect it's bigger than the advantage you get from using SGX; There are other ways to get privacy.

Re: Intel deprecates SGX on Core series processors

#112

Post by betterunix2 »

kibwen wrote: post #7
josephcsible wrote: post #2

Good riddance. (For those unaware, basically the only use-case of SGX was hardware-enforced DRM.)

On consumer CPUs DRM may have been the only use case, and indeed good riddance. But on the server side it's possible for tenants to use these hardware features to run workloads that the hosts verifiably cannot modify or inspect. In other words, this lets you use AWS/GCP/Azure etc. while keeping both your data and your code competely opaque to Amazon/Google/Microsoft etc. Disclaimer: my job is to write the software th…

Except that the security model on the server side is broken as there is no way for Intel to know that a key is compromised and thus revoke it; at least for the DRM use-case sharing cracked keys on forums is common. Why would an attacker ever share keys in the tenant/host case? Moreover, is there some reason to believe that Amazon, Google, or Microsoft would struggle to extract a key if they are indeed malicious? Is there a good reason to believe that Intel would never just give keys to certain government agencies when asked? If you are worried about a malicious host, SGX/etc. are at best a partial, very limited solution even if all you care about is integrity/attestation.

SGX and TEEs generally are and always were a DRM solution, with the server use-case mostly being an afterthought that the marketing teams pushed hard. They also create a fantastic forced-obsolescence program as they require active support on the part of chip makers throughout an application's lifecycle; Intel can arbitrarily deprecate otherwise functional CPUs by just not revoking compromised keys (and perhaps releasing a few into the wild just to force people to upgrade).

Re: Intel deprecates SGX on Core series processors

#113

Post by aaaaaaaaata »

Uptrenda wrote: post #49

Many moons ago, I wrote a prototype on Azure's 'confidential computing' VMs that demonstrated how a computer could 'prove' to another that it was running certain code using 'attestations.' I thought it was cool as hell, and honestly thought that if such a technology held up you could build many interesting things with it. Potentially, it would have had many use-cases in the DeFi industry, privacy-preserving computati…

We can just use phones or USB sticks as signing keys, for anything and everything — why does nobody talk about/want/demand this?!

Re: Intel deprecates SGX on Core series processors

#114

Post by kibwen »

userbinator wrote: post #46
kibwen wrote: post #7

Earlier quoted context omitted.

On consumer CPUs DRM may have been the only use case, and indeed good riddance. But on the server side it's possible for tenants to use these hardware features to run workloads that the hosts verifiably cannot modify or inspect. In other words, this lets you use AWS/GCP/Azure etc. while keeping both your data and your code competely opaque to Amazon/Google/Microsoft etc. Disclaimer: my job is to write the software th…

But on the server side it's possible for tenants to use these hardware features to run workloads that the hosts verifiably cannot modify or inspect. IMHO that is still a bad thing because it violates some fundamental principles around what ownership really means.

The hosts still have the authority to refuse to allow tenants to run encrypted workloads. The concept of ownership is preserved, but some owners may choose to give up their ability to snoop in order to attract tenants who otherwise would be incapable of using cloud infrastructure at all.

Re: Intel deprecates SGX on Core series processors

#115

Post by betterunix2 »

kibwen wrote: post #8
thinkmassive wrote: post #5

They claim SGX support on Xeon is still “full steam ahead” https://community.intel.com/t5/Blogs/Products-and-Solutions/...

Specifically the next generation of SGX is pushing ahead, since a number of flaws were identified in the original design.

I'm taking bets on how long before the next generation is completely broken as well. It is only a matter of time, and the timeline is likely short.

Re: Intel deprecates SGX on Core series processors

#116

Post by betterunix2 »

tux3 wrote: post #42
derefr wrote: post #37

Earlier quoted context omitted.

How do you find out what CPU your VM is running on in a compute cloud, in order to ask Intel about it? You can't go to the data center and look at the serial number printed on the chip. It's probably negative-ROI for an IaaS vendor to have the ops staff at the DC to go do that as a customer service. And AFAIK there's nothing like a control-plane API for querying a hypervisor's hardware serial numbers in an IaaS-maint…

Yes. If you extract keys, you win the game. I think their best answer is a sort of blacklist system where if Intel becomes aware one of their key has leaked, their servers could stop telling people it is genuine (this gets into the details of EPID and DCAP that I really don't want to clutter my memory with, so my retelling may be less accurate there) To prevent the idea with fake certificates, I think you "simply" pi…

There is already a blacklisting/revocation system for leaked SGX keys -- which failed completely when it was put to the test, after researchers tried publishing some keys they extracted on Twitter. However, it depends on Intel becoming aware of a leaked key, which makes perfect sense for the original DRM use-case and makes no sense in the cloud/server/hosting/etc. use-case.

Re: Intel deprecates SGX on Core series processors

#117

Post by anamexis »

aaaaaaaaata wrote: post #113
Uptrenda wrote: post #49

Many moons ago, I wrote a prototype on Azure's 'confidential computing' VMs that demonstrated how a computer could 'prove' to another that it was running certain code using 'attestations.' I thought it was cool as hell, and honestly thought that if such a technology held up you could build many interesting things with it. Potentially, it would have had many use-cases in the DeFi industry, privacy-preserving computati…

We can just use phones or USB sticks as signing keys, for anything and everything — why does nobody talk about/want/demand this?!

We do it all the time with our phones with Apple Pay/Google Pay.

Re: Intel deprecates SGX on Core series processors

#118

Post by betterunix2 »

mike_hearn wrote: post #92
marcan_42 wrote: post #13

Earlier quoted context omitted.

Of course, that requires tenants trust Intel's security. As a security researcher and given past showings from Intel, I wouldn't put much faith in SGX, even if they try to fix past flaws. SGX as a concept for tenant-provider isolation requires strong local attacker security, which is something off the shelf x86 has never had (not up to contemporary standards, ever) and certainly not in anything Intel has put out. The…

You trust the security of your CPU vendor in all cases. SGX doesn't change that. If Intel wanted to, they could release a microcode update that detects a particular code sequence running and then patches it on the fly to create a back door. You'd never even know. "SGX as a concept for tenant-provider isolation requires strong local attacker security, which is something off the shelf x86 has never had" Off the shelf C…

"SGX is hard because it's trying to preserve the open nature of the platform"

Except that was an afterthought. Originally only whitelisted developers were allowed to use SGX at all, back when DRM was the only use-case they had in mind.

Re: Intel deprecates SGX on Core series processors

#119

Post by skybrian »

phire wrote: post #98
eightysixfour wrote: post #59

Earlier quoted context omitted.

It is gone now, but IIRC Microsoft was working on a blockchain for inter-enterprise settlement that ran in the secure enclave. It had extremely high throughput and all of the parties could “trust” that the code running was the same, so they were all following the same rules. Neat concept, they killed it before ever sharing source code.

I have seen a deployed altcoin built on SGX. Can't remember the name or if it was even successful. In my opinion, it's a huge risk. With a regular blockchain, the fact that someone might maliciously be running the wrong code is baked into the design, and the security model has to handle it. With SGX, you are relying on Intel's security model to make sure everyone is running the same code. If SGX is ever broken (which…

It seems like this argument proves too much, because it rules out defense in depth. Why have multiple layers of defense when one perfect layer does the job?

I think the answer is that you're never really sure that your defense is perfect, and that's true of both SGX and byzantine algorithms.

Re: Intel deprecates SGX on Core series processors

#120

Post by ZiiS »

betterunix2 wrote: post #115
kibwen wrote: post #8

Earlier quoted context omitted.

Specifically the next generation of SGX is pushing ahead, since a number of flaws were identified in the original design.

I'm taking bets on how long before the next generation is completely broken as well. It is only a matter of time, and the timeline is likely short.

Only having it on expensive chips will probably help as much as anything.
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