4 ms·

I have some bad news for you: that's possible with just about every computer introduced since 2013. Google "Intel Management Engine" or "AMD PSP" or "ARM Trust

I have some bad news for you: that's possible with just about every computer introduced since 2013. Google "Intel Management Engine" or "AMD PSP" or "ARM TrustZone". The last of these could, in theory, be less bad, except no ARM licensee except Rockchip (and maybe Apple -- jury is still out there) has chosen the "be less bad" option.

fastball 5y ago
I'd say this is more in-line with Intel SGX than Intel ME.
- anonymousDan 5y ago
  SGX is implemented on top of ME and relies on it for a substantial fraction of its functionality. You are right though that trustzone and sgx are both TEEs.
  - namibj 5y ago
    I wish especially AMD would offer Java Card support through their PSP to the operating system, at least if the PSP is resistant to MMIO attacks on the integrity of the Java Card memory. Being able to open a Diffie-Hellman encrypted, mutual-signature-authenticated channel to a remote device to then receive an AES key for disk encryption is far better than some TPM header that can easily be sniffed with physical access. Would be even better if NVMe SSDs were able to authenticate themselves and let you transfer in a key over a DIffie-Hellman channel so sniffing the PCIe bus wouldn't deliver the key (or a non-PFS-encrypted encapsulated form of it) to an attacker. The speeds of NVMe SSDs unfortunately prevent LUKS from being cheap, and TCG Opal is kind of a joke from a security standpoint (doesn't even (seem to) specify that the provided "password" is used to derive a key, suggesting that it may just be used via a password hash to compare against a database entry to decide whether to unlock a disk encryption key). Even TPMs don't seem to encrypt the communications channel they use with the CPU/PSP, and they are often socketed which makes MITM attacks easy with physical access. If they'd offer Java Card, they'd at least be somewhat useful...
fulafel 5y ago
On a phone it's in active use, on your x86 device it's up to you.
- octoberfranklin 5y ago
  No, it is most definitely not up to you. That's the problem.
  - fulafel 5y ago
    Depends on how paranoid you are. There's no absolute assurance that my x86 hardware and OS aren't secretly using them for some active purpose without user knowledge, but all the evidence so far points to the fact that it's not, and the reputation risks to the vendors would be large if they got caught doing this kind of underhanded thing. Whereas my phone OS core functionality relies on the functionality and I know it's being used all the time for DRM etc. (I'm not hapy with the x86 situation either, but it's still less bad)

fastball 5y ago

I'd say this is more in-line with Intel SGX than Intel ME.

anonymousDan 5y ago
SGX is implemented on top of ME and relies on it for a substantial fraction of its functionality. You are right though that trustzone and sgx are both TEEs.
- namibj 5y ago
  I wish especially AMD would offer Java Card support through their PSP to the operating system, at least if the PSP is resistant to MMIO attacks on the integrity of the Java Card memory. Being able to open a Diffie-Hellman encrypted, mutual-signature-authenticated channel to a remote device to then receive an AES key for disk encryption is far better than some TPM header that can easily be sniffed with physical access. Would be even better if NVMe SSDs were able to authenticate themselves and let you transfer in a key over a DIffie-Hellman channel so sniffing the PCIe bus wouldn't deliver the key (or a non-PFS-encrypted encapsulated form of it) to an attacker. The speeds of NVMe SSDs unfortunately prevent LUKS from being cheap, and TCG Opal is kind of a joke from a security standpoint (doesn't even (seem to) specify that the provided "password" is used to derive a key, suggesting that it may just be used via a password hash to compare against a database entry to decide whether to unlock a disk encryption key). Even TPMs don't seem to encrypt the communications channel they use with the CPU/PSP, and they are often socketed which makes MITM attacks easy with physical access. If they'd offer Java Card, they'd at least be somewhat useful...

fulafel 5y ago

On a phone it's in active use, on your x86 device it's up to you.

octoberfranklin 5y ago
No, it is most definitely not up to you. That's the problem.
- fulafel 5y ago
  Depends on how paranoid you are. There's no absolute assurance that my x86 hardware and OS aren't secretly using them for some active purpose without user knowledge, but all the evidence so far points to the fact that it's not, and the reputation risks to the vendors would be large if they got caught doing this kind of underhanded thing. Whereas my phone OS core functionality relies on the functionality and I know it's being used all the time for DRM etc. (I'm not hapy with the x86 situation either, but it's still less bad)