Invisibook

Introduction

Invisibook is a decentralized privacy order book project. It is built on Ethereum L1 and achieves on-chain matching, off-chain settlement, and on-chain verification through a combination of MPC (Multi-Party Computation) + ZK (Zero-Knowledge proofs).

In Invisibook, the trading instruments and quoted prices are public, but the order quantities on-chain are in ciphertext form. The public and counterparties can only execute trades — they cannot discover the other party’s position size (even using AI or quantitative trading algorithms). This protects traders’ privacy and prevents reverse engineering of positions, front-running (rat trading / insider trading), and various forms of MEV that erode large profits.

安全多方计算（MPC）允许多个参与方在不暴露各自私有数据的前提下，共同计算一个函数的值。SPDZ 是一种被广泛使用的 MPC 协议，它不仅保护隐私，还能抵抗恶意行为者，即使某些参与方试图作弊或篡改数据，协议也能检测出来并保证结果正确性。其关键技术之一就是信息论安全的消息认证码（MAC）机制。

Alice 和 Bob，他们手里分别持有一个无符号整数，Alice持有x， Bob持有y。
此时他们想互相比较出x和y的大小关系， 但同时又不想泄漏自己手里具体的数，此时我们该如何解决呢？