3

I have implemented the Trusted Computing Group's TSS Version 1.2 Direct Anonymous Attestation according to their specification and this includes the Anonymity Revocation. There have been papers discussing privacy flaws among corrupt administrators but it seems that it's only a problem if the base names are not random - that is if they are named.

I use random basenames and I like that idea anyway because it enhances privacy. Random base names are useful for unlinkable applications, such as anonymous web browsing (see "Direct Anonymous Attestation: Enhancing Cloud Service User Privacy." - references it sites for flaws are concerned with linked basenames).

The literature over the years has been ambiguous. I sent out email to one of the algorithm designers of the TPM 1.2 DAA schemes and he has not responded. I'm wondering if anyone out there has an answer. I am holding off of deployment of this implementation I spent many hours on until I can get an answer on whether the anonymity revocation feature of the 1.2 spec is useful. Thanks in advance.

2

I should prefix this by warning you that this is not an area I have a lot of experience with, but from what I've read the DAA anonymity revocation was added by the working group as a feature for potential beneficial use, but no discussion was had around what scenario might make practical use of it.

The only possible case I can think of is some kind of cross-verification system in which two separate services require proof that the same device is being used for both of them, while also maintaining some privacy via a chosen random base name for that pair of systems.

I am wholly unaware of any system which uses this in reality, and it appears that nobody has thus far had any interest in implementing it for practical use.

1
  • There are applications such as "smart roads" that maintain the privacy/anonymity of the driver. – Bill Martin Jan 12 '17 at 15:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.