How Does Blockchain Transform Cross‑Border Clearing? Insights from China Merchants Bank

Many people have a vague idea of blockchain. An analogy likens it to a trusted third‑party witness in a bet, and China Merchants Bank (CMB) offers a deep view on how it can improve cross‑border clearing.

Blockchain is a hot topic in recent years, described as a decentralized, trust‑less distributed ledger. Its core technical mechanisms include a public/private key system and consensus algorithms, typically implemented via a peer‑to‑peer (P2P) network.

Blockchains are generally classified into three types: public chains, consortium (or alliance) chains, and private chains. The openness of a blockchain determines its implementation details, such as consensus choice and data distribution.

Integrating blockchain with existing information systems changes system architecture. The presentation and application layers often remain unchanged, while the business and data layers adopt blockchain technology. Business logic is split into on‑chain and off‑chain parts: off‑chain logic does not interact with the blockchain and stores data independently, whereas on‑chain logic handles operations that benefit from decentralization, leading to a hybrid data model.

In consortium and private chain scenarios, deploying a blockchain application requires tightly coupling traditional components with the blockchain system. This tight coupling can reduce duplicated effort across organizations, especially in payment and settlement where multiple entities maintain separate ledgers that must be reconciled.

According to McKinsey research, new technologies affect the financial‑tech stack differently: the internet reshaped interaction products, cloud computing impacted business, big data enhanced risk control, and blockchain significantly influences the lower three layers—settlement infrastructure, system interaction, and rule setting.

Blockchain also brings security and privacy challenges. Private keys, which prove asset ownership, are vulnerable if stored only in software; cold‑storage solutions mitigate risk but introduce usability issues. Privacy is conflicted: data must be hidden from unrelated parties yet verifiable by relevant ones. Emerging techniques like ring signatures and homomorphic encryption aim to resolve this, especially under strict regulatory scrutiny.

Smart contracts enable code‑based contractual clauses but raise legal and technical problems. Legal professionals must understand how code translates to legal obligations, and technical bugs can have severe consequences. Versioning and upgrades of contracts across nodes add further complexity.

Consensus algorithms are not perfect. Proof‑of‑Work (PoW) offers decentralization and high fault tolerance but suffers from latency and high resource consumption. Consortium chains often use Byzantine Fault Tolerance or modified algorithms, which lower energy use but limit scalability. Selecting and tuning the appropriate consensus mechanism for a given scenario is essential.

CMB’s blockchain exploration focuses on extensive industry collaboration, building an internal expertise team, and developing a proprietary blockchain platform. Existing cross‑border clearing systems at CMB are limited to head‑office‑to‑branch interactions, involve many manual steps, and are hard to extend to new overseas branches.

By adopting blockchain, CMB created a cross‑border clearing system that connects its six overseas institutions and the head office on a shared ledger, allowing any two entities to initiate and settle transactions directly.

The system’s advantages include streamlined settlement, reduced manual processing, easier onboarding of new overseas branches, and improved overall efficiency.