Author: Vince Quill, CoinTelegraph; Compiler: Wuzhu, Golden Finance
Zero-knowledge (ZK) proofs — a method of verifying information without revealing the specific content of that information — have become a popular approach to creating decentralized identity products.
Despite the hype, Ingo Rübe, CEO and co-founder of decentralized identity provider KILT Protocol, explained that the highly technical nature of ZK proofs make it difficult for governments and institutions to adopt them.
In an interview, the KILT CEO explained that decentralized identifiers such as biometric data can be selectively shared with parties and verified on-chain using Merkle Trees (a data structure that all computer scientists understand), which is easier, faster, and more efficient than ZK.
Rübe also believes that the open source software typically used in ZK solutions could be a ticking time bomb, leading to large-scale data breaches exposing sensitive user data:
“Companies using zero-knowledge proofs usually take a library from someone else, and that person has been making something open source, but nobody takes responsibility. So what happens if this thing doesn’t work as we expect?”
“The best thing you can do is use a public permissionless blockchain to store the validity of the credentials,” the CEO said, before asserting that users must have the self-sovereignty to own and create their digital identifiers, which are stored locally and verified using a decentralized blockchain network.
The World Wide Web Consortium has developed standards for decentralized identity solutions in 2022. Source: World Wide Web Consortium
Decentralized Identity Solutions: The Future of Identity
Rübe noted that contrasting approaches to decentralized identity solutions are suitable for different, unique use cases and applications (including ZK proofs), but stressed that using ZK proofs for decentralized identity is "like trying to kill a fly with a bazooka."
Despite daunting technical hurdles, some companies and governments are experimenting with ZK-powered identity solutions. In October 2024, the launch of a decentralized identity for residents powered by ZKsync Era was announced.
Recently, on October 17, World (formerly Worldcoin) announced the next generation of biometric data collection spheres and touted alternative methods of personal identity verification, most notably the company's World ID Credentials program. The program will allow anyone holding an NFT-enabled government passport to register their identity in the World system.