Constant-Sum Fingerprinting for Winternitz One-Time Signature

A fingerprinting function for hash-based Winternitz one-time signature is proposed. A hash-based one-time signature is a light-weight and quantum-immune alternative to digital signature schemes that typically make use of number theoretic problems. The Winternitz scheme, which is one of the most promising hash-based one-time signatures, realizes the function of digital signatures by utilizing several hash chains. In computing a signature, a fingerprinting function is used to specify certain positions in the hash chains. This study proposes a fingerprinting function that reduces the size of a signature and the operational cost for the verification of a signature. The proposed fingerprinting function can be combined with another improvement technique of the Winternitz scheme, and contributes to the discussion that promotes practical use of the Winternitz scheme.