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How Does Blockchain Support Data Privacy?

Živile Šarkauskaite

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Živile Šarkauskaite

September 12, 2023

Blockchain technology has emerged as a potent tool for protecting data privacy in today’s increasingly digital environment when personal information is continuously at risk of being revealed. Therefore, the question emerges: How does blockchain support data privacy?

In this article, we’ll examine how blockchain supports data privacy, enabling both individuals and organizations to protect private data.

Bitcoin in a system

What is blockchain, and how does it work?

Blockchain technology, in its simplest form, is a distributed, peer-to-peer digital database. Satoshi Nakamoto introduced blockchain technology in 2008 when he created Bitcoin, a pioneering cryptocurrency.

Across network nodes, these decentralized ledger technologies store data in a special format.

Blockchain processes transactions across numerous computers to create a chain of immutable blocks that are linked via hashes. This architecture protects sensitive information against compromise.

Since there is no central authority required, users can deal with one another without any middlemen getting in the way, thanks to decentralization.

Initially synonymous with cryptocurrencies, blockchain applications have expanded to include smart contracts, non-fungible tokens (NFTs), decentralized finance (DeFi) apps, and more.

This versatile technology can store various data types securely, making it a vital component of a more interconnected global business landscape.

Private vs. public blockchain

Blockchain networks can be categorized into two primary types: public and private, each with distinct characteristics.

Public blockchains are highly accessible to the general public, fostering greater decentralization and resilience against censorship and manipulation.

They eliminate the risk associated with a single central authority and promote transparency by allowing public access to transaction records. This openness enables independent verification and bolsters the overall integrity of the network.

In contrast, private blockchains are confined to specific user groups and are more centralized because a single authority maintains control.

Access to a private blockchain is regulated by this central authority, ensuring that only verified individuals can participate. This method prioritizes data security and privacy by reducing the possibility of infiltration by fraudulent criminals.

Controlled access also improves processing times and scalability in private blockchains. This ability to regulate the quantity and quality of nodes contributes to the network’s potency.

Data privacy and storage security concerns

It’s widely acknowledged that blockchains vary in terms of their data security, creating data privacy concerns.

Public blockchains, for instance, may not offer robust protection for sensitive information. making them unsuitable for certain business applications.

Blockchains can take on a variety of network configurations, each of which presents its own unique set of data privacy concerns for users and organizations.

Numerous high-profile cryptocurrency breaches resulting in significant financial losses demonstrate that common blockchain is not impervious to fraud or cyberattacks.

For example, hackers could penetrate a worker’s machine and steal confidential company information.

Some problems with regulations also exist. Many businesses would like to adopt blockchain technology, but many are hesitant to do so because of the lack of clarity surrounding the technology in the legal sphere.

Businesses in countries with stringent rules on the trading of cryptocurrency may find this process especially challenging.

The blockchain on a computer

How does blockchain support data privacy and storage security?

So how does blockchain support data privacy? It not only empowers users by restoring ownership of their information in areas like the healthcare system, but it also fosters trust through transparency and complete control.

In light of the escalating concerns surrounding personal and commercial data privacy due to cyber breaches and hacks, there are many ways blockchain safeguards personal data and promotes data privacy.


Decentralization is the cornerstone of blockchain security, setting it apart from traditional databases that centralize data storage.

In contrast, blockchain distributes data across multiple locations, creating a distributed ledger. This unconventional approach necessitates unique strategies for data privacy.

Transparency characterizes every transaction on the blockchain, which is not confined to a single computer but stored across a network of devices worldwide.

The collective management of the blockchain system involves every device holding a copy of all transactions. When a node introduces a new block to the chain, it undergoes verification by other nodes within the blockchain network.

If a hacker wants to manipulate records within the blockchain network, they must gain control of at least 51% of the blockchain.

However, this endeavor demands substantial financial and resource investments. In case of success, addition grants access to the stored information within the blockchain.

Block and hash

Blockchain consists of a chain of blocks, each comprising three essential components: data or information, block hash, and previous block’s hash.

A block hash serves as a unique identification number, generated through a cryptographic hash function, providing each block on the blockchain with a distinct digital fingerprint.

Furthermore, each block stores the hash of the preceding block, enhancing the security and effectiveness of the blockchain system.

If any alteration occurs within a block, its hash changes, causing the subsequent block to reference a different hash, rendering all subsequent blocks invalid.

This feature makes hashes a robust tool for detecting changes and tampering within blockchain data, ensuring data protection and integrity.

However, this method is not the most secure, given modern technological advancements enabling swift tampering and recalculation of block data. To address this challenge, additional data breach prevention measures are essential.

Zero-knowledge proof

Zero-knowledge proof is a powerful technique for safeguarding data privacy within blockchain systems. It enables an individual to demonstrate the truth of a statement to others without divulging any additional information.

During a transaction, the prover can convincingly validate a known value to the verifier while preserving data confidentiality.

Imagine a situation where someone wants to prove they have a valid credit card to make a purchase. Normally, they’d show the full card details. However, this exposes sensitive information.

Alternatively, the person could use a zero-knowledge proof approach. In this scenario, a secure system stores the card’s validity information (private key) without revealing the full card details (stored data).

Imagine, when making a purchase, the person shows verification that their credit card is legitimate for the transaction without giving out the actual card number or any other private information.

They may make the purchase safely and safeguard the sensitive data on their card in this way.

These zero-knowledge proof tokens make it possible for users to conduct untraceable DeFi transactions by hiding certain data bits while still enabling transaction verification.

The combination of privacy safeguards and blockchain’s inherent transparency creates a trustworthy setting for information exchange.

Blockchain federated identity DIDS

Blockchain advocates emphasize individual control over their digital identity with decentralization as a key security measure.

Decentralized identity allows users to create a digital identity independently, free from service provider dependency.

This self-sovereign identity (SSI) encompasses not only usernames, passwords, and search histories but also personally identifiable information (PII), including biometric data, social security numbers, addresses, and more.

Blockchain’s decentralized ledger enables Decentralized Identity (DID). Users can securely store personal information independently of website databases on devices like PCs, mobiles, digital databases, and any cloud storage, with metadata as pointers.

Organizations use metadata to verify user claims. Users can create multiple DIDs, each of which will be secured by their unique private key.

However, only the person who possesses the private key can validate the saved data. It serves a similar purpose as email address verification.

The federated identity framework is established and supported by using a single sign-on (SSO) authentication protocol.

However, centralized systems that utilize federated identities and the SSO protocol can be vulnerable to security risks because they consolidate data in a single location, making it more susceptible to breaches or unauthorized access.

Blockchain-based federated identities eliminate third-party dependence, enhance data protection, and offer smart contract audits for granular data access control.

The future of blockchain data privacy

There will certainly be further developments in cryptography methods and privacy-preserving protocols in the future of blockchain privacy. Advancements in cryptography have the potential to significantly protect blockchain networks.

For example, homomorphic encryption permits computation on encrypted data without compromising it, and secure multi-party computation allows multiple users to collaboratively compute a function without revealing their inputs.

Due to its value, more businesses will likely adopt blockchain as a solution to their problems as the technology develops.


In general, blockchain technology is a powerful tool for ensuring the safety of private data in today’s increasingly digital society.

Blockchain’s decentralized control, openness, encryption techniques, and cutting-edge software are key to ensuring integrity and making data secure.

Moreover, data is not kept in a single location. Therefore, decentralization makes it more difficult for hackers to gain access. A transparent system makes it easy to spot tampering.

Blockchain combines cryptography and immutable records to keep information unchanged. With zero-knowledge proofs, information may be validated without disclosing any private details.

Users can control their private information and digital identities, which is useful for decentralized identification systems. This facilitates people to maintain ownership of their data.

In the big picture of data security, blockchain data protection is a strong defence against unauthorized entry and breaches.


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