Direct Anonymous Attestation (DAA) in More Depth

Direct Anonymous Attestation is TPM2’s method of providing mathematically-proven anonymity or pseudonymity for signing keys in trusted platforms. The simple explanation of how DAA works is that it has a single verification (public) key but a plethora of signing (private) keys. One cannot tell which of many platforms created the signature. This chapter provides a more thorough explanation and enables one to understand (amongst other things) why one can’t tell whether two anonymous DAA signatures were created under the same private key, but can tell whether two pseudonymous DAA signatures were created under the same private key. This chapter is intended for readers with a background or interest in mathematics and/or cryptography.