L13-PALLADIUM Datasheet, PDF (7/7 Pages) List of Unclassifed Manufacturers – Palladium, Zero Knowledge

3.4 Applying ZK to Palladium
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Figure 5: Information gained by Verifier after t iterations of above communication protocol
This gives us a triple (u, b, l) which we claim is indistinguishable from the actual transcript generated
by the Prover-Verifier protocol above. (This is for an honest verifier. If the verifier actually generates
b in some other way, such as making it depend on u, then this simulation needs to be modified by
filtering the output appropriately. Details omitted in this class. But in any case, the Verifier can
simulate the distribution on transcripts, which proves that the protocol is ZK.)
A much more general and wonderful result is also known. Indeed, for any polynomial time program
P , I can convince you (in zero knowledge) that I know x, y, z, etc. such that P (x, y, z, . . . ) = true,
where P () is some polynomial time program. Clearly, this is quite a powerful cryptographic tool.
3.4 Applying ZK to Palladium
The Secure Support Component (SSC) of Palladium is a hardware module that can perform certain
cryptographic operations as well as securely store one or more cryptographic keys. It has the public-
private key pair (SK₀, P K₀) that is burned into the machine (as we mentioned earlier).
I want to convince a CA in zero-knowledge that I know SK₀, P K₀, C₀, SK₁ such that:
- SK₀ is the secret key for P K₀
- C₀ is a certificate from Dell on P K₀
- SK₁ is the secret key for P K₁ (CA knows P K₁)
At this point if the CA is convinced it returns cert(P K₁). Thus the CA can certify P K₁ without
knowing how to link it to the original public key P K burnt into the SSC by the manufacturer.