PKC2021 - Signatures
Updatable Signatures and Message Authentication Codes
https://eprint.iacr.org/2021/365 introduce a definitional framework for updatable signatures (USs) and message authentication codes (UMACs)./ provide generic constructions from key-homomorphic primitives (signatures and PRFs) as well as direct constructions/ instantiate these primitives from various assumptions such as DDH or CDH (latter in bilinear groups), or the (R)LWE and the SIS assumptions./ obtain highly practical US schemes from BLS signatures or UMAC schemes from the Naor-Pinkas-Reingold More Efficient Digital Signatures with Tight Multi-User Security
https://eprint.iacr.org/2021/235 first generic construction of efficient signature schemes with tight multi-user security against adaptive corruptions./ based on lossy identification schemes/ achieve strong existential unforgeability/a new variant of the generic construction of signatures from sequential OR-proofs/ in the NPROM/ building block for tightly-secure authenticated key exchange protocols Improving Revocation for Group Signature with Redactable Signature
https://eprint.iacr.org/2020/856 group signatures with time-bound keys/ allow high granularity revocation: a member’s signing key can in particular be deactivated at some moments and then be automatically reinstated/ using redactable signature/ Group Signatures with User-Controlled and Sequential Linkability
https://eprint.iacr.org/2021/181 a new variant of group signatures that provides linkability in a flexible and user-centric manner/ Users – and only they – can decide before and after signature creation whether they should remain linkable or be correlated./ allow for sequential link proofs Two-Party Adaptor Signatures From Identification Schemes
https://eprint.iacr.org/2021/150 show that signature schemes that are constructed from identification (ID) schemes, which additionally satisfy certain homomorphic properties, can generically be transformed into adaptor signature schemes./ provide an impossibility result which proves that unique signature schemes (e.g., the BLS scheme) cannot be transformed into an adaptor signature scheme./ define two-party adaptor signature schemes with aggregatable public keys and show how to instantiate them via a generic transformation from ID-based signature schemes./ instantiations of our generic transformations for the Schnorr, Katz-Wang and Guillou-Quisquater signature schemes Banquet: Short and Fast Signatures from AES
https://eprint.iacr.org/2021/068 with post-quantum security, constructed using only symmetric-key primitives./based on the MPC-in-head paradigm/ uses only standardized primitives, namely AES and SHA-3/ The MPC protocol in Banquet uses a new technique to verify correctness of the AES S-box computations