Blind Signatures

Signature schemes that let a signer sign a message without seeing it, and round-complexity lower bounds for them.

Status	Problem	Tags
	No round-optimal pairing-free blind signature Open for a polynomial query budget. The impossibility is proved when \(\mathsf{User}_2\) and \(\mathsf{Verify}\) together make \(O(\log\lambda)\) random-oracle queries, including when oracle outputs contain group elements; the superpolynomial message space hypothesis is retained. 5 open	Black Box Separations Blind Signatures Generic Group Model Signature Schemesggmimpossibilityadaptation (ai)
	Three moves from DL, ROM only Open: three moves, black-box in the group, ROM only, from DL alone. Three moves is achieved from DDH in the ROM and from DL in AGM+ROM; four moves is achieved from DL in the ROM. 5 open	Blind Signatures Random Oracle Model Signature Schemes Tight Reductionsromassumption