Sandi: A System for Accountability

  • Kim Laine, Microsoft

Kim Laine presents a novel reputation system called Sandi, which aims to create trust between two otherwise distrusting parties. Concretely, Sandi focuses on online communication scenarios, where two communicating parties do not know each other, yet would benefit from a degree of initial trust. Sandi can be seen as a reputation system that measures bad behavior, with strong integrity protections and resistance to manipulation. We discuss the problem Sandi aims to solve, the construction of the Sandi protocol, our strong security and privacy guarantees, and an optimality argument showing that Sandi incentivizes good behavior. The full paper is available at https://arxiv.org/abs/2401.16759 (opens in new tab) and will be presented at IEEE EuroS&P 2025.

Taille: Cryptography Talk Series