## Cryptology ePrint Archive: Report 2019/371

Generic Construction of Linkable Ring Signature

Xueli Wang and Yu Chen and Xuecheng Ma

Abstract: We propose a generic construction of linkable ring signature from any compatible ring signature scheme and one-time signature scheme. Our construction has both theoretical and practical interest. In theory, our construction gives the first generic transformation from ring signature to linkable ring signature, which brings at least two main benefits: first, the transformation achieves the lowest bound of the complexity that constructing linkable ring signature schemes. Second, ours preserves the anonymity of underlying ring signature schemes. In practice, our transformation incurs a very small overhead in size and running time. By instantiating our construction using the ring signature scheme (eprint 2018) and the one-time signature scheme (TCHES 2018), we obtain a lattice-based linkable ring signature scheme whose signature size is logarithmic in the number of ring members. This scheme is practical, especially the signature size is very short: for $2^{30}$ ring members and security level of 100-bit, our signature size is only 4MB. In addition, we give a new proof approach in proving the linkability, which might be of independent interest towards the proof in the random oracle model.

Category / Keywords: public-key cryptography / ring signature, linkable ring signature, generic construction, lattice-based

Date: received 5 Apr 2019, last revised 12 Apr 2019

Contact author: wangxueli at iie ac cn,yuchen prc@gmail com,maxuecheng@iie ac cn

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2019/371

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