Privacy and security are two words that come up repeatedly during any conversation about blockchain. However, it would be incorrect to say that blockchain generally excels or underperforms in both areas.
While measures such as hashing algorithms and public/private key pairs are the foundation of distributed ledger security, transactions recorded on public blockchains are visible to everyone. So they can never be described as private. In addition, while blockchain technology has many inherent security qualities, there are also notable shortcomings and attack vectors due to manipulation of network nodes, endpoint vulnerabilities, etc.
That’s why many smart technologists in recent years have started working seriously on solutions to strengthen the privacy and security of blockchains, as well as the dApps that live on them. Many such solutions involve an iteration of Zero-Knowledge (ZK) technology, a branch of advanced cryptography typically associated with data privacy. Fortunately, there are good reasons to believe that such implementations will strengthen blockchain’s security credentials once and for all.
Zero-Knowledge technology in action
The increasing integration of ZK technology into blockchain is a response to the industry’s growing need for data and transactional privacy, especially as adoption increases. Despite the increasing number of users interacting with blockchain, many remain cautious about using it due to networks’ very public transaction history. This is where ZK-tech comes in. Current implementations of ZK technology in blockchain include:
- Zero-Knowledge Succinct Non-interactive Argument of Knowledge (ZK-SNARK): A ZK protocol that enables private transactions by masking personal data, including the wallet addresses of the sender and recipient.
- Zero-Knowledge Scalable Transparent Argument of Knowledge (ZK-STARK): A cryptographic technology for validating proofs in a highly efficient and private WAY.
- ZK-Powered Smart Contracts (ZKApps): smart contracts powered by zero-knowledge technology.
- ZK-Rollups: A Layer-2 solution aimed at addressing Ethereum’s scalability issues, reducing transaction fees and increasing throughput.
In general, discussions of ZK technology tend to focus on Zero-Knowledge proofs, protocols that allow one party (the prover) to demonstrate to another party (the verifier) that they have certain information – without losing the information to reveal yourself. This model simultaneously guarantees the confidentiality of the data validate its authenticity.
In the context of blockchain, ZKPs can be used to enable confidential transactions, where details such as transaction inputs, outputs and amounts are hidden, but the transaction remains verifiable and compliant with the rules of the blockchain. Disclosing transaction data on a public network is no longer a problem.
A notable implementation of Zero-Knowledge proofs can be seen in Zcash (ZEC), the privacy-focused cryptocurrency. Zcash uses ZKP (particularly ZK-SNARK) to provide users with extensive anonymity, ensuring that details remain private even though transactions are recorded on the blockchain. Money (XMR), another untraceable privacy currency, uses a form of ZKP known as Bulletproofs.
A vision of modular privacy on blockchains
Privacy coins like Monero and Zcash have proven to be a godsend for privacy-conscious crypto users, though they have been controversially targeted by lawmakers, many of whom have forced exchanges to delist the assets and others like them.
In addition to tokens, the privacy-on-blockchain movement includes specific protocols such as Tornado Cash, an open-source, non-custodial “tumbler” that obscures the origins of digital funds. This, too, has proven controversial: Last year, the company’s co-founder Roman Storm was indicted after claiming he helped facilitate money laundering worth more than $1 billion.
And yet, privacy is not inherently controversial, and many blockchain users are actively embracing solutions that help them navigate the Web3 world with confidence. An emerging project that exemplifies the potential of ZK technology to achieve this goal is Namada, an asset-agnostic Layer1 protocol. While the above projects were standalone, Namada introduces the concept of modular privacy, giving users the ability to place privacy on disparate chains and assets.
This vision for modular privacy is made possible by two key features, which both ZKPs use: the Unified Shielded Set (USS) and Shielded Actions (SA). Inspired by Zcash’s Sapling architecture, Namada’s Multi-Asset Shielded Pool (MASP) enables various assets coexist within the Unified Shielded Set. In other words, privacy between different assets can be ‘turned on’, allowing users to add layers of privacy to assets from non-private blockchains.
Shielded Actions, meanwhile, facilitate complex, privacy-protecting actions across multiple blockchains And decentralized applications (dApps). In a sense, SAs can be considered their own privacy layer for the DeFi space, providing peace of mind to transparent networks like Ethereum, Osmosis, and Celestia.
Namada has already proven its multi-chain capabilities through a reliable two-way bridge to Ethereum. However, the ultimate goal is to lead the way in a future where privacy is not just an additional feature, but an integral part of blockchain interactions.
The integration of Zero-Knowledge technology into blockchain represents a paradigm shift in the way privacy and security are perceived and implemented in Web3. With projects like Namada leading the way, the future of blockchain looks not only more secure, but also more private, opening up new possibilities for users and developers alike.