The concept of blockchain, once confined primarily to IT and financial circles, has surged into public awareness following a collective study session by China’s central political bureau. Suddenly, terms like blockchain, digital currency, and electronic payments have become mainstream topics of discussion. Among these, the relationship between blockchain and digital currency has drawn particular attention.
"Gold and silver are not inherently money, but money is inherently gold and silver." By analogy, can blockchain — a tamper-proof, decentralized database — share a similarly intrinsic relationship with digital currency? What exactly is the connection between the two? And where is central bank digital currency (CBDC) headed?
To answer these questions, Yao Qian, General Manager of China Securities Depository and Clearing Corporation and former Director of the People’s Bank of China Digital Currency Research Institute, offers authoritative insights into the evolution and future of blockchain and digital currencies.
The Cryptographic Origins of Blockchain
Modern cryptography achieved a revolutionary breakthrough with the development of asymmetric encryption, solving the limitations of symmetric key systems in large-scale secure communications.
In 1976, Whitfield Diffie and Martin Hellman introduced the concept of splitting a single key into a public-private key pair. The public key could be openly shared for encryption, while the private key remained secret for decryption. For example, if Alice wants to send a message to Bob, she encrypts it using Bob’s public key — only Bob’s private key can decrypt it.
This principle was first implemented in 1978 through the RSA algorithm by Rivest, Shamir, and Adleman. Beyond secure transmission, asymmetric cryptography enabled digital signatures: Alice could sign a message with her private key, allowing others to verify its authenticity using her public key — a foundational mechanism for trust in digital systems.
👉 Discover how cryptographic principles power next-generation financial systems.
Hash functions represent another milestone. Algorithms like SHA (developed by the U.S. National Security Agency) and China’s SM3 generate fixed-size outputs from any input — fast to compute forward, nearly impossible to reverse. These are used not only in securing data but also in generating wallet addresses and linking blocks in blockchain systems.
The Emergence of Digital Currency
The idea of digital cash emerged from a simple question: If emails can be encrypted and signed, why not money?
In 1982, David Chaum proposed "blind signatures" — a cryptographic method enabling anonymous, untraceable electronic payments. His system laid the groundwork for early e-cash experiments and introduced core concepts still relevant today.
However, Chaum’s model relied on centralized institutions (banks, merchants), leading to scalability issues due to growing databases tracking spent coins.
Then came Bitcoin. In 2008, Satoshi Nakamoto introduced a decentralized electronic cash system built on peer-to-peer networking and a novel data structure: the Unspent Transaction Output (UTXO). Instead of tracking spent transactions, Bitcoin tracks what hasn’t been spent — reducing data overhead.
By combining hashing with timestamping and consensus mechanisms, Nakamoto created a distributed ledger maintained by network participants competing to validate transactions. This innovation eliminated the need for intermediaries and made direct person-to-person value transfer possible over the internet.
How Blockchain Transforms Traditional Systems
Blockchain is more than just technology — it's a paradigm shift across multiple domains:
- System Architecture: Decentralized nodes act as both clients and servers, empowering end users.
- Accounting: Distributed Ledger Technology (DLT) ensures transparency, immutability, and real-time reconciliation — potentially enabling instant balance sheets.
- Identity & Accounts: Users generate private keys locally, derive public keys, and create wallets independently — bypassing traditional banking accounts.
- Value Exchange: Enables disintermediated asset trading — turning blockchain into a "trust machine."
- Organization Design: Facilitates decentralized collaboration without hierarchical control.
- Economic Models: Introduces algorithmic economies that blend market dynamics with automated coordination.
Current Challenges in Blockchain Adoption
Despite its promise, blockchain faces several hurdles:
- Performance: Full-node validation across thousands of participants slows transaction speeds. Bitcoin transactions may take minutes or even hours.
- Privacy: Public ledgers expose transaction histories. Solutions like zero-knowledge proofs and homomorphic encryption are emerging.
- Security: Smart contracts are prone to vulnerabilities. Formal verification methods are needed to ensure code integrity.
- Governance: On-chain decision-making lacks standardized mechanisms for community consensus.
- Interoperability: No universal protocol exists for cross-chain communication, limiting ecosystem integration.
Future Directions in Blockchain Technology
Several technical advancements will shape blockchain’s evolution:
- Consensus Mechanisms: Balancing security and efficiency remains critical. Innovations include new algorithms, layered architectures (like sharding), and hardware acceleration.
- Cross-Chain Interoperability: As enterprises adopt different chains (public, consortium, private), seamless interaction becomes essential.
- Regulatory Integration: For tokenized securities, embedding compliance features — such as KYC/AML checks — directly into blockchain systems via监管联盟链 (supervisory consortium chains) is crucial.
- Self-Sovereign Identity: Blockchain enables decentralized identity management, giving individuals control over their digital identities.
- Privacy-Preserving Models: Users can maintain anonymity while proving transaction validity without revealing personal data.
- Digital Wallet Evolution: Wallets are transforming into gateways for digital asset ecosystems — offering asset management, DApp access, and real-world integrations.
- Smart Contract Governance: Given their deterministic nature, smart contracts require fail-safes allowing human intervention when necessary.
- Convergence with Other Technologies: Integration with cloud computing, big data analytics, AI, and distributed file systems enhances use cases like asset securitization and supply chain finance.
👉 Explore how integrated technologies are reshaping global finance.
Cryptocurrency vs Third-Party Payments: A Fundamental Divide
While platforms like Alipay use encryption for data transmission, they differ fundamentally from cryptocurrencies.
Alipay operates within a multi-layered account system reliant on dedicated networks — costly and exclusionary, especially for cross-border payments. In contrast, cryptocurrency leverages existing internet infrastructure, enabling universal access and peer equality.
From a privacy standpoint, centralized payment providers hold user data centrally — creating single points of failure and abuse risks (e.g., Facebook’s 50 million user data breach). Blockchain offers a new model: users control their data through cryptographic keys, deciding who sees what and under what conditions.
The Future of Central Bank Digital Currencies
Facebook’s Libra (now Diem) didn’t copy Bitcoin or Alipay — it proposed a hybrid model blending innovation with monetary stability. This reflects the likely path forward: next-generation digital money must integrate cutting-edge tech while preserving core monetary principles.
Yao Qian emphasizes that central bank cryptocurrency (CBCC) is a major research direction for CBDCs — including China’s initiative. While many global pilots (e.g., Canada’s Jasper, Singapore’s Ubin) explore blockchain-based wholesale CBDCs, retail applications remain challenging due to scalability and operational burdens.
China’s prototype adopts a hybrid approach:
- A blockchain-based确权账本 (title verification ledger) provides tamper-proof public query services — acting as a digital "note authenticator."
- Core transaction processing uses traditional distributed systems to avoid performance bottlenecks.
- A two-tier ledger structure (central + sub-ledgers) reduces central bank workload while maintaining oversight.
This design balances innovation with stability — leveraging blockchain where it adds value without being constrained by its limitations.
Libra vs National CBDCs: Contrasting Approaches
Though both use cryptographic techniques, key differences exist:
| Aspect | Libra (Diem) | National CBDCs |
|---|---|---|
| Issuer | Private consortium | Central banks |
| Platform | Open-source (Apache 2.0) | Often closed/proprietary |
| Anonymity | Pseudonymous | Likely tiered privacy |
| Account Linkage | Wallet-based | May link to bank accounts |
| Asset Issuance | Supports multiple assets | Typically single sovereign currency |
Libra’s open-source model invites global participation — fostering rapid iteration and market alignment. In contrast, most CBDC projects operate as closed “Manhattan-style” initiatives, potentially limiting agility and inclusivity.
Ultimately, all digital currencies must survive market competition.
Frequently Asked Questions
Q: What is the main difference between cryptocurrency and third-party payment apps like Alipay?
A: Cryptocurrencies operate on decentralized networks using cryptography for ownership and transfer, while third-party payments rely on centralized account systems controlled by private companies.
Q: Is blockchain essential for central bank digital currencies?
A: Not necessarily. While many CBDC prototypes use blockchain for specific functions (e.g., verification), core transaction processing may use traditional architectures to ensure speed and scalability.
Q: Can individuals control their own data with CBDCs?
A: It depends on design. Some models support self-sovereign identity via cryptographic keys; others may prioritize regulatory compliance over full user autonomy.
Q: How does CBDC differ from Bitcoin?
A: CBDCs are issued by central banks, legal tender, and designed for stability. Bitcoin is decentralized, speculative, and not backed by any government.
Q: Will CBDCs replace cash?
A: Initially, they’re intended to complement physical cash (M0), especially in digital-first economies. Full replacement would depend on adoption, policy, and infrastructure.
Q: Can CBDCs work across borders?
A: Cross-border interoperability is a key goal. Projects like mBridge are exploring multi-CBDC platforms for international settlements.
👉 Learn how next-gen financial infrastructure is being built today.