23
votes
What's the difference between the endorsement key and the attestation identity key within the TPM?
Unfortunately there is not a single source of truth about attestation. I'll try to make it as clear as possible and cite when necessary.
TL;DR: The Endorsement Key is used to prove that you are ...
- 601
16
votes
Accepted
What are the functional similarities and differences between TPM and SGX in trusted computing?
Well first off, SGX is not a crypto chip. It is a feature built into Intel chipsets themselves, whereas the TPM is often a discrete chip positioned on the LPC bus, though sometimes it can be emulated ...
- 67.3k
12
votes
Accepted
What are the differences between HSM and SE?
A hardware security module (HSM), a secure element (SE), a smart card, a trusted execution environment (TEE) and a secure enclave (SE again) are all computing environments designed for secure ...
8
votes
Practicality of outsourcing password hashing using enclaves
While trusted execution environments are useful, I don't think that outsourcing password hashing from server to the client is the right approach.
Either the server only has the hashed password for ...
- 208k
7
votes
Difference between TPM, TEE and SE
A little more on the functional aspects:
TPM is fixed, well-specified functionality by an ISO and TCG standard. You can‘t just add or change this.
Usually it‘s a discrete security chip connected ...
- 121
7
votes
What is known about the capabilities of AMD's Secure Processor?
I was interested in the same issue and did some preliminary research. I'll try to answer some of the questions, though as a non-AMD engineer I cannot be certain.
Does it have software-updatable ...
- 171
7
votes
Accepted
Is a cryptographically signing camera possible?
Both Nikon and Canon have cameras that can digitally sign photos so you might look for technical details on how they do this. At the same time, you want a better system than they implemented as a ...
- 2,215
6
votes
What is known about the capabilities of AMD's Secure Processor?
So what I would say is anything that provides direct memory access and essentially does processing on behalf of the processor is a whole other set of threat surfaces you are introducing to the ...
- 2,777
6
votes
Accepted
What really is the difference between firmware TPM and a discrete one and should it be trusted more?
It is very hard to quantify security and justify trust. Before you read on: think about what you want to protect against whom. Make a risk analysis.
I have heard mainly two justifications why physical ...
- 601
5
votes
How are TPMs provisioned for Intel Trusted Execution Environment (TXT)?
The Intel TXT is a complex system designed to provide a hardware layer of security that can prevent software layer changes from resulting in increased access for attackers. Through use of stored ...
- 1,451
5
votes
Extra features required for TrustZone to provide main security features
Strictly speaking, you can't do anything with TrustZone itself. TrustZone itself is an isolation feature of the CPU core. It adds another level to isolation between processes: in addition to user/...
4
votes
How are TPMs used to detect tampering?
Good question. To my knowledge, this is where most of the Trusted Computing confusion comes from.
Yes, it's important to understand that while the TPM collects measurements (PRCs) from DRTM (e.g. ...
- 1,443
4
votes
Accepted
Can I prove the relation between AIK and EK without asking to the TPM 2.0?
In short, no. But, that doesn't mean that asking the TPM to use the EK is difficult -- definitely no more difficult than asking for a quote (the primary part of an attestation).
First, a nitpick: the ...
- 418
4
votes
Asymmetric/Symmetric Encryption of a TPM key hierarchy
Because of the limited size of the possible payload of an RSA encryption, most systems use a hybrid approach. The details are usually hidden from the user: you never see the symmetric session key used ...
- 8,654
4
votes
Is a cryptographically signing camera possible?
As @ThoriumBR stated, yes it’s possible …
Like so many things, while the concept is straight forward, the details and intent become complex very quickly.
What are you cryptographically signing and ...
- 8,213
3
votes
If smart hardware is evil can I still securely run software?
This answer is a practical take on it. I'll not theorize about encryption, but will take a round trip to earlier attempts at secretive computation.
Whilst I do agree with Numeron that at some point ...
- 5,897
3
votes
Accepted
Where to store signing key in TPM
The private key that you store was encrypted by the TPM itself before it left the TPM, and can be decrypted only using the TPM's primary key (which only exists inside the TPM). The encrypted key you ...
- 8,654
3
votes
What are the differences between HSM and SE?
The insides of a smart card, small HSM (USB dongle size), TPM, SE, etc. are all the same. There is a question of how much storage it has, which primitives/algorithms are supported, and how many ...
- 8,654
3
votes
Accepted
What Trusted Execution Environment (TEE) solutions exist for mobile devices?
At least for ARM-based CPUs, there's TrustZone. While not the same, it is possible "SGX-like" instructions and capabilities will carry over in the future.
Each of the physical processor cores in ...
- 3,042
2
votes
Is there any mechanism available in Android platform for remote attestation?
The current answers here are now out of date. The Google Pixel 2 now contains the hardware support for remote attestation, and has it's own variant to meets the needs of the TPM. "TEE - trusted ...
- 29
2
votes
Accepted
In practice, does TPM SRK really be decrypted by EK first, before it decrypt its child keys
The SRK is not encrypted by EK. Both are not required to be encrypted at all. Their security are based on their physical protection and the logic of the TPM itself - no API are to provide their ...
- 1,443
2
votes
Decrypting keys wrapped by the Storage Root Key (SRK) of a TPM
TrustZone and TPM (with its SRK) are two very different things. I'll try to deferenciate both of those before explaining how they can be used to achieve what you explained.
TrustZone is an ARM ...
- 1,443
2
votes
Accepted
Does periodically rebooting secure-boot-enabled devices improve security by preventing persistent compromise?
Periodic rebooting does very little to improve device security in general.
Secure boot is designed to protect your system from attacks that target the boot process, e.g. the part of a computer's ...
- 9,293
2
votes
Differences between Intel TXT and Linux IMA
No, they are complementary.
DRTM provides a Root of Trust on which you can build applications/use-cases such as Integrity measurement of your entire linux system (IMA). However, it is not part of it. ...
- 1,443
2
votes
what make a TEE secure?
TEE is secure mainly because of the key store is placed directly on the CPU and access to it is limited to security functions of the CPU (SoC). Also, the memory is spitted in between secure and non-...
- 1,230
2
votes
Is ransomware that threatens with publication and verifiably deletes upon payment possible?
I don't see any way how this could be possible. When you have a copy of data, there is no way to prove that no other copy of that data exists, because you can not prove a negative. Trying to prove a ...
- 49.6k
2
votes
Is ransomware that threatens with publication and verifiably deletes upon payment possible?
I don't think it's possible to prove that you DON'T know a piece of information.
This is relevant to your question because in order to guarantee that he won't publish your files after payment is ...
- 9,293
2
votes
Verifying that the CRTM is read-only for the purpose of trusted computing
As the name implies, a CRTM is the Core Root of Trust for Measurement. By definition, a Root of Trust of a given system is trusted because its correct operation cannot be verified by that system. In ...
- 66
2
votes
With TPM how are the initial PCR values seeded with 'good' values?
What you asked is the PCR values from so-called "golden measurement" or "baseline measurement", which can be conducted by the platform manufacturer such as DELL or platform administrator like your ...
- 121
2
votes
Is a cryptographically signing camera possible?
Yes, it's entirely possible, but it will depend on the manufacturer. They must implement a functionality on the firmware creating a keypair on the camera, e signing every picture taken. The private ...
- 55.5k
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