On the Security of an Unconditionally Secure, Universally Composable Inner Product Protocol

TL;DR

This paper analyzes the security of a distributed inner product protocol, revealing information leakage issues that can allow one party to fully learn the other's input, challenging its unconditional security claims.

Contribution

It identifies and demonstrates security flaws in a previously proposed DIP protocol, highlighting scenarios where privacy can be compromised.

Findings

Information leakage occurs in the protocol.

Leakage can enable complete input recovery.

Security flaws challenge unconditional security claims.

Abstract

In this paper we discuss the security of a distributed inner product (DIP) protocol [IEEE TIFS, 11(1), (2016), 59-73]. We show information leakage in this protocol that does not happen in an ideal execution of DIP functionality. In some scenarios, this information leakage enables one of the parties to completely learn the other party's input. We will give examples of such scenarios.