Isogeny-based Group Signatures and Accountable Ring Signatures in QROM. (arXiv:2110.04795v3 [cs.CR] UPDATED)

We provide the first isogeny-based group signature (GS) and accountable ring
signature (ARS) that are provably secure in the quantum random oracle model
(QROM). We do so by building an intermediate primitive called openable sigma
protocol and show that every such protocol gives rise to a secure ARS and GS.
Additionally, the QROM security is guaranteed if the perfect unique-response
property is satisfied. Our design, with the underlying protocol satisfying this
essential unique-response property, is sophisticatedly crafted for QROM
security. …

ring signatures