Yusuke Sakai

A privacy-enhanced access log management mechanism in SSO systems from nominative signatures

2017 · International Journal of Applied Cryptography

In online services, a service provider (SP) manages access logs containing customers' buying histories. Therefore, user's information is revealed from the exposed logs if each customer can be linked. In fact, such information exposure has …

mbrs: A Library for Minimum Bayes Risk Decoding

2024 · arXiv (Cornell University)

Minimum Bayes risk (MBR) decoding is a decision rule of text generation tasks that outperforms conventional maximum a posterior (MAP) decoding using beam search by selecting high-quality outputs based on a utility function rather than …

On Key Substitution Attacks against Aggregate Signatures and Multi-Signatures

2025

When we use signature schemes in practice, we sometimes should consider security beyond unforgeability. This paper considers security against key substitution attacks of multi-signer signatures (i.e., aggregate signatures and multi-signatures). Intuitively, this security property ensures …