BDEC: Enhancing Learning Credibility via Post-Quantum Digital Credentials

Keywords: Digital Credential; Anonymous; Post-Quantum; Blockchain

Digital credentials can streamline the verification process, reduce fraud, and enhance the portability and accessibility of academic records, and thus digital credentials become increasingly essential for verifying academic achievements and qualifications in a rapidly digitizing world. However, current research on digital credentials in the education scenario falls into two categories: 1) blockchain-verifiable credentials, which either rely on blockchain security or classical cryptographic problems and are not quantum-safe; and 2) post-quantum anonymous credentials, primarily lattice-based, facing challenges in achieving conditional linkability and efficient revocation.

In this paper, we propose a generic framework for constructing an anonymous credential system named Blockchain-based Digital Education Credential (BDEC). Our framework requires only a digital signature scheme and a zkSNARK. We formally prove the unforgeability, anonymity, and unlinkability of the proposed framework and show that it additionally supports conditional linkability and revocability. By instantiating the framework with the post-quantum signature Loquat [Crypto’24] and zkSNARK Aurora [Eurocrypt’19], we construct a post-quantum anonymous credential system whose security relies on collision-resistant hash functions and the Legendre PRF. Furthermore, our resulting system offers significant improvements in its concrete performance over the lattice-based system [Crypto’23].