Privacy and security are two words that come up repeatedly during any conversation about blockchain. However, it would be inaccurate to say that blockchain, as a rule, excels or under-delivers in either area.
While measures like hashing algorithms and public/private key pairs are the bedrock of security for distributed ledgers, transactions recorded on public blockchains are available for all to see. Thus, they can never be described as private. Moreover, while blockchain tech has many inherent security qualities, there are also notable flaws and attack vectors due to network node manipulation, endpoint vulnerabilities, etc.
Which is why many bright technologists have, in recent years, started seriously working on solutions to bolster the privacy and security of blockchains, as well as the dApps that live on them. Many such solutions involve some iteration of Zero-Knowledge (ZK) technology, a branch of cutting-edge cryptography generally associated with data privacy. Thankfully, there is good reason to believe that such implementations will bolster blockchain’s security credentials once and for all.
Zero-Knowledge Tech in Action
The increasing integration of ZK technology in blockchain is a response to the industry’s growing need for data and transactional privacy, particularly as adoption widens. Despite the rising numbers of users interacting with blockchain, many remain cautious about engaging due to networks’ very public transaction histories. This is where ZK tech comes to the fore. Current implementations of ZK technology in blockchain include:
- Zero-Knowledge Succinct Non-interactive Argument of Knowledge (ZK-SNARK): A ZK protocol that facilitates private transactions by masking personal details including the wallet addresses of the sender and receiver.
- Zero-Knowledge Scalable Transparent Argument of Knowledge (ZK-STARK): A cryptographic technology for validating proofs in a highly efficient and private MANNER.
- ZK-Powered Smart Contracts (ZKApps): Smart contracts powered by zero-knowledge tech.
- ZK-Rollups: A Layer-2 solution aimed at addressing Ethereum’s scalability issues, reducing transaction costs, and increasing throughput.
In general, discussions of ZK tech tend to focus on Zero-Knowledge proofs, protocols that allow one party (the prover) to demonstrate to another (the verifier) that they hold certain information – without revealing the information itself. This model ensures the confidentiality of the data while also validating its authenticity.
In the context of blockchain, ZKPs can be employed to facilitate Confidential Transactions wherein details like transaction inputs, outputs, and amounts are concealed – yet the transaction remains verifiable and compliant with the blockchain’s rules. Exposure of transaction data on a public network ceases to be a concern.
A notable implementation of Zero-Knowledge proofs is seen in Zcash (ZEC), the privacy-centric cryptocurrency. Zcash leverages ZKP (specifically ZK-SNARK) to offer users comprehensive anonymity, ensuring that while transactions are recorded on the blockchain, the details stay private. Monero (XMR), another untraceable privacy currency, uses a form of ZKP known as Bulletproofs.
A Vision for Modular Privacy on Blockchains
Privacy coins like Monero and Zcash have proven to be a godsend for privacy-conscious crypto users, although they have controversially been targeted by lawmakers, many of whom have forced exchanges to delist the assets and others like them.
As well as tokens, the privacy-on-blockchain movement encompasses specific protocols like Tornado Cash, an open-source, non-custodial “tumbler” that obfuscates the origins of digital funds. This, too, has proven controversial: last year, the company’s cofounder Roman Storm was indicted after claims he helped facilitate over $1 billion in money laundering.
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 end is Namada, an asset-agnostic Layer1 protocol. While the aforementioned projects were standalone, Namada introduces the concept of modular privacy, giving users the ability to bolt privacy onto disparate chains and assets.
This vision for modular privacy is enabled thanks to two key features, both of which use ZKPs: the Unified Shielded Set (USS) and Shielded Actions (SA). Inspired by Zcash’s Sapling architecture, Namada’s Multi-Asset Shielded Pool (MASP) allows various assets to coexist within the Unified Shielded Set. In other words, privacy across different assets can be “turned on,” enabling users to add privacy layers to assets from non-private blockchains.
Shielded Actions, meanwhile, facilitate complex, privacy-preserving actions across multiple blockchains and decentralized applications (dApps). SAs can, in a sense, be considered their own privacy layer for the DeFi space, bringing peace of mind to transparent networks like Ethereum, Osmosis, and Celestia.
Namada has already proven its multi-chain capabilities through a trustless two-way bridge to Ethereum. Its ultimate aim, however, is to operate at the forefront of a future where privacy is not just an added feature but an integral part of blockchain interactions.
The integration of Zero-Knowledge technology in blockchain represents a paradigm shift in how privacy and security are perceived and implemented in Web3. With projects like Namada leading the charge, the future of blockchain looks not only more secure but also more private, opening up new possibilities for users and developers alike.