Blockchain for Healthcare: Ensuring Data Integrity and Security

Blockchain:

Blockchain is essentially a decentralized distributed database that enables the distributed recording and storage of data. It is a data structure that links blocks together in a chain. Blockchain technology employs cryptographic methods to create a tamper-proof, trustworthy database that records events in chronological order. This database is stored in a decentralized manner, ensuring effective data security and enabling participants to reach consensus on the chronological order of transactions and the current state of the entire network.

Blockchain Technology:

In summary, blockchain technology refers to a technology that collectively maintains a reliable database through decentralized and trustless mechanisms. Blockchain is not a single, entirely new technology; rather, it is the integration of multiple existing technologies (such as cryptographic algorithms and peer-to-peer file transfer). These technologies are ingeniously combined with databases to create a novel approach to data recording, transmission, storage, and presentation. Simply put, blockchain technology is a system in which all participants jointly record and store information.

Blockchain Classification:

Blockchain is currently categorized into three types: public blockchain, consortium blockchain, and private blockchain.

Public Blockchain:Public blockchains are truly decentralized distributed blockchains. System security is ensured by mechanisms such as Proof of Work (PoW) or Proof of Stake (PoS). They facilitate application deployment, are accessible globally, and do not rely on any single company or jurisdiction. Participants in public blockchains often enjoy strong anonymity; any participant can write to and read from the chain, as well as participate in transaction validation. The Bitcoin blockchain is the prime example of a public blockchain.

Consortium Blockchain:Consortium blockchains adopt a multi-centric architecture, with participating members pre-selected based on specific criteria (e.g., market participants within NASDAQ, strategic analysts from various securities firms, etc.). Nodes responsible for transaction confirmation within the system are also predefined and validated through consensus mechanisms. Depending on the level of trust and specific requirements within the consortium, virtual digital currencies can be either anonymous or non-anonymous. Consortium blockchains facilitate straightforward permission control settings and offer greater application scalability, holding significant value for cross-industry or cross-border clearing, settlement, and auditing. They can substantially reduce the costs and time associated with remote settlements, providing a simpler and more efficient alternative to existing systems while inheriting the advantages of decentralization and alleviating monopoly pressures.

Private Blockchain:Private chains are not decentralized but possess distributed characteristics. The central controller specifies the scope of members eligible to participate and perform transaction validation. For members within a private chain, the system does not require cryptocurrency incentives. Private chains hold significant value for internal audit testing within corporations and governments, as well as for transaction settlement among banking institutions within a consortium.

Blockchain Features:

Since blockchain records all transactions in plain text within blocks from the genesis block onward, and the resulting data records are immutable, any value exchange between transacting parties can be traced and queried. This fully transparent data management system is not only legally robust but also provides a trusted shortcut for tracking in existing logistics, operational log recording, auditing, and other applications.

Decentralization:Blockchain is a public ledger maintained by miner nodes for record-keeping and stored across decentralized nodes worldwide. Because every node and miner must adhere to the same transaction recording rules, which are based on cryptographic algorithms rather than trust, and because each transaction requires approval from other users within the network, there is no need for third-party intermediaries (such as banks) or trusted institutions to provide endorsement. In traditional centralized networks, an effective attack on a central node (e.g., a third-party payment intermediary) can compromise the entire system. In contrast, in a decentralized network such as blockchain, attacking a single node cannot control or disrupt the entire network; controlling 50% of the nodes is merely the starting point for gaining control.

Trustless System:In a blockchain network, algorithmic self-constraint ensures that any malicious attempt to deceive the system is rejected and suppressed by other nodes; therefore, it does not rely on central authorities for support or credit endorsement. In traditional credit-endorsed network systems, participants must place sufficient trust in a central institution, and as the number of participants increases, system security declines. In contrast, within a blockchain network, participants do not need to trust any specific entity; instead, system security strengthens as the number of participating nodes grows, while data content can be made fully transparent.

Tamper-Proof and Encrypted Security: Blockchain employs a one-way hash algorithm, and each newly generated block is strictly advanced in chronological linear order. The irreversibility of time ensures that any attempt to intrude upon or tamper with data within the blockchain can be easily traced, leading to rejection by other nodes, thereby restricting the emergence and execution of related illegal activities.

Core Application Advantages of Blockchain Technology:

Blockchain technology can construct an unbreakable timestamping system. Without requiring mutual trust among nodes within the system, it ensures that all data records are authentic, thereby forming a honest, orderly, decentralized, and distributed database. Furthermore, the value involved in exchanges within the system can be flexibly programmed. By applying these core values to real-life scenarios, blockchain can help us address the following key issues:

Decentralized Distributed Structure: Significantly Reduces Intermediary Costs in Practice

As blockchain technology can serve as a tool for large-scale collaboration among individuals without the need for mutual trust, it can be applied to many traditional centralized domains to handle transactions previously managed by intermediaries. We believe that the financial sector’s foundational infrastructure—such as securities clearing and registration systems and cross-border remittance and settlement systems—will face the most significant disruption from blockchain technology in the future. These systems are currently centralized, characterized by high fees and low efficiency. If blockchain technology can be successfully deployed in these areas, its application prospects would be highly compelling, even if it saves only 1% of intermediary costs.

Tamper-Proof Timestamps: Solving Data Traceability and Information Anti-Counterfeiting Issues

In today’s society, our lives are inundated with vast amounts of forged information and data, ranging from counterfeit wine, substandard milk sources, and high-imitation luxury goods, to fraudulent invoice schemes, falsified financial statements, and underground banking transactions. Blockchain technology has opened a new frontier in data traceability and information anti-counterfeiting. As data within a blockchain is chronologically linked to form an immutable timestamp, it enables the creation of tamper-proof authentic records for all items. This capability significantly aids in combating counterfeit and shoddy products and enforcing informational discipline in the real world.

A Secure Trust Mechanism: Addressing the Core Flaws of Current IoT Technology

The Internet of Things (IoT) is a current hotspot and an inevitable trend in the near future. However, traditional IoT models rely on a centralized data center to collect all information, leading to significant flaws in aspects such as device lifecycle management. Blockchain technology can establish trust consensus across the entire network without requiring trust in individual nodes, thereby effectively addressing some core deficiencies of IoT. This enables devices not only to connect with each other but also to operate autonomously, accelerating our transition into the era of the Internet of Value.

Flexible Programmability: Helping to Standardize Existing Market Order

In today’s society, due to the lack of standardized market order, we cannot guarantee that our assets will retain their intended value in the future when transferred. With the advent of blockchain, if we leverage its programmable features by embedding code during asset transfers to stipulate the future use and direction of those assets, we will usher in a entirely new market and social paradigm.

Evolution of Blockchain:

Blockchain 1.0: Digital Currency

Blockchain technology emerged alongside Bitcoin, with its initial applications focused entirely on digital currencies. The advent of Bitcoin brought blockchain into the public spotlight for the first time, subsequently leading to the creation of alternative cryptocurrencies such as Litecoin, Ethereum, and Dogecoin. The emergence of programmable money has made it possible for value to circulate directly over the internet. Blockchain has established a novel decentralized digital payment system, whose appeal lies in its ability to facilitate anytime, anywhere monetary transactions, seamless cross-border payments, and low-cost operational efficiency within a decentralized framework. The rise of these new digital currencies has profoundly disrupted the traditional financial system.

Blockchain 2.0: Digital Assets and Smart Contracts

Influenced by digital currencies, people have begun to expand the application of blockchain technology to other financial sectors. Leveraging the programmable nature of blockchain, efforts have been made to incorporate the concept of “smart contracts” into blockchain systems, giving rise to programmable finance. Supported by contract systems, blockchain applications have expanded from a singular focus on currency to other financial domains involving contractual functionalities. The emergence of new concepts such as Colored Coins, BitShares, Ethereum, and Counterparty has enabled blockchain technology to gain prominence in numerous financial areas, including stocks, clearing, and private equity. Currently, many financial institutions are researching blockchain technology and attempting to implement it in practice, thereby disrupting the existing traditional financial system.

Blockchain 3.0: The Great Society of Blockchain

As blockchain technology continues to advance, its features of “decentralization” and “data anti-counterfeiting” are gradually gaining attention in other fields. People have come to realize that the application of blockchain may not be limited to the financial sector but can be extended to any area with relevant needs. Consequently, beyond finance, blockchain technology has been successively applied to other domains such as notarization, arbitration, auditing, domain names, logistics, healthcare, email, authentication, and voting, expanding its scope of application to society as a whole. In this stage of adoption, efforts are being made to use blockchain to disrupt the underlying protocols of the internet and to integrate blockchain technology into the Internet of Things (IoT), thereby ushering the entire society into the era of the intelligent internet and creating a programmable society.

Hash Algorithm:

Hashing algorithms map binary values of arbitrary length to shorter, fixed-length binary values, known as hash values. A hash value is a unique and highly compact numerical representation of a data segment. If a plaintext message is hashed and even a single character within that message is altered, the resulting hash will yield a different value. It is computationally infeasible to find two distinct inputs that produce the same hash value; therefore, hash values can be used to verify data integrity. They are commonly employed in fast lookup operations and cryptographic algorithms.

A fixed-size result obtained by applying a one-way mathematical function (sometimes referred to as a "hashing algorithm") to any amount of data; if the input data changes, the hash will also change. Hashes can be used in many operations, including authentication and digital signatures. Also known as a "message digest." It is a one-way cryptographic system, meaning it is an irreversible mapping from plaintext to ciphertext, with only an encryption process and no decryption process. Meanwhile, a hash function can transform inputs of arbitrary length into outputs of fixed length. The one-way nature and fixed-length output characteristics of hash functions enable them to generate message or data digests.

Smart Contract:

Smart contracts are essentially computer protocols that can automatically execute contracts or invalidate relevant clauses in accordance with programmed rules. The business logic embedded in the contract is executed on the blockchain cloud (without the need for servers), automatically enforcing the terms of the given agreement among multiple parties. In the blockchain environment, the development of contracts or smart contracts means that blockchain transactions will extend far beyond simple currency buying and selling; broader instructions can be embedded into the blockchain, and these instructions are automatically executed by the system once predefined conditions are met. While traditional agreements also involve mutual consent or dissent regarding certain actions, the distinguishing feature of smart contracts is that the parties no longer need to trust each other beforehand. This is because smart contracts are not only defined by code but also enforced by code. Smart contracts can operate in this manner primarily due to three characteristics: autonomy, self-sufficiency, and decentralization. Autonomy means that once the contract is initiated, it runs without any intervention from the initiator. Secondly, smart contracts can autonomously acquire resources, obtaining funds by providing services or issuing assets to meet potential needs. Furthermore, smart contracts do not rely on a single centralized server; instead, they operate automatically through a distributed network of nodes, thereby avoiding the risk of third-party manipulation.

Asymmetric Encryption Algorithm:

Asymmetric encryption algorithms require two keys: a public key and a private key. The public key and the private key form a pair. If data is encrypted with the public key, it can only be decrypted with the corresponding private key; conversely, if data is encrypted with the private key, it can only be decrypted with the corresponding public key. Because different keys are used for encryption and decryption, this method is referred to as asymmetric encryption. The basic process for implementing secure information exchange using asymmetric encryption is as follows: Party A generates a key pair and makes one of the keys, the public key, available to other parties. Party B, upon obtaining this public key, uses it to encrypt confidential information and then sends the encrypted data to Party A. Party A then decrypts the received information using their own retained private key.

Characteristics of asymmetric cryptography include: high algorithmic complexity, with security relying on both the algorithm and the keys. However, due to this complexity, encryption and decryption speeds are slower than those of symmetric cryptography. In symmetric cryptography, there is only one key, which is kept secret; thus, decryption requires the recipient to possess this key. Consequently, ensuring security hinges on safeguarding the key. In contrast, asymmetric cryptography employs two keys, one of which is public. This eliminates the need to transmit the recipient’s key as required in symmetric cryptography, thereby significantly enhancing security.

Note: Some of the information in this article is sourced from CITIC Securities, Shenwan Hongyuan Securities, and other sources, for which we extend our gratitude. Please stay tuned for VCBeat’s upcoming special feature on blockchain.