CryptoDB
Jonas Lindstrom
Publications and invited talks
Year
Venue
Title
2025
RWC
zkLogin: Privacy-Preserving Blockchain Authentication with Existing Credentials
Abstract
For many users, a private key based wallet serves as the primary entry point to blockchains. Commonly recommended wallet authentication methods, such as mnemonics or hardware wallets, can be cumbersome. This difficulty in user onboarding has significantly hindered the adoption of blockchain-based applications.
In this talk we will present zkLogin, a novel technique that leverages identity tokens issued by popular platforms (any OpenID Connect enabled platform e.g., Google, Facebook, etc.) to authenticate transactions. At the heart of zkLogin lies a signature scheme allowing the signer to sign using their existing OpenID accounts and nothing else. This improves the user experience significantly as users do not need to remember a new secret and can reuse their existing accounts. zkLogin provides strong security and privacy guarantees. Unlike prior works, zkLogin’s security relies solely on the underlying platform’s authentication mechanism without the need for any additional trusted parties (e.g., trusted hardware or oracles).
As the name suggests, zkLogin leverages zero-knowledge proofs (ZKP) to ensure that the sensitive link between a user’s off-chain and on-chain identities is hidden, even from the platform itself. zkLogin enables a number of important applications outside blockchains. It allows billions of users to produce verifiable digital content leveraging their existing digital identities, e.g., email address. For example, a journalist can use zkLogin to sign a news article with their email address, allowing verification of the article’s authorship by any party.
We have implemented and deployed zkLogin on the Sui blockchain as an additional alternative to traditional digital signature-based addresses. Due to the ease of web3 on-boarding just with social login, many hundreds of thousands of zkLogin accounts have already been generated in various industries such as gaming, DeFi, direct payments, NFT collections, sports racing,
cultural heritage, and many more.
Coauthors
- Foteini Baldimtsi (1)
- Konstantinos Kryptos Chalkias (1)
- Yan Ji (1)
- Jonas Lindstrom (1)
- Deepak Maram (1)
- Ben Riva (1)
- Arnab Roy (1)
- Mahdi Sedaghat (1)
- Joy Wang (1)