A Response to: A Note on "Privacy Preserving n-Party Scalar Product Protocol"

TL;DR

This paper defends a privacy-preserving n-party scalar product protocol against security and scalability concerns, clarifying misunderstandings and emphasizing its practical use in specific scenarios.

Contribution

The authors clarify misconceptions about their protocol's security and scalability, reaffirming its safety and practicality in certain applications.

Findings

The protocol is secure for its intended purposes.

Scalability limitations are manageable in specific scenarios.

The protocol is practical for vertically partitioned, few-party applications.

Abstract

We reply to the comments on our proposed privacy preserving n-party scalar product protocol made by Liu. In their comment Liu raised concerns regarding the security and scalability of the $n$-party scalar product protocol. In this reply, we show that their concerns are unfounded and that the $n$-party scalar product protocol is safe for its intended purposes. Their concerns regarding the security are based on a misunderstanding of the protocol. Additionally, while the scalability of the protocol puts limitations on its use, the protocol still has numerous practical applications when applied in the correct scenarios. Specifically within vertically partitioned scenarios, which often involve few parties, the protocol remains practical. In this reply we clarify Liu's misunderstanding. Additionally, we explain why the protocols scaling is not a practical problem in its intended application.