Quark ID Wallet

QuarkID is a Self-Sovereign Identity protocol developed by the Government of the City of Buenos Aires that launched in 2023. The protocol implements W3C DID and Verifiable Credentials standards to enable users to control their digital identity credentials through a decentralized architecture. The system operates on multiple blockchain networks including zkSync, Ethereum, Polygon, and Rootstock, with credentials stored off-chain in users' personal wallets.

The technical architecture comprises several key components including a Mobile Agent, Message Manager, ZKSync API, Proxy API, and DWN (Decentralized Web Node). The protocol follows core SSI principles including:

• Decentralized identity management without central authorities
• User control over credential sharing and privacy
• Peer-to-peer interactions using cryptographic proofs
• Interoperability through standard protocols like OpenID Connect, DIF, and Trust over IP

Notable implementation: The protocol has been adopted by the City of Buenos Aires government for official digital credentials, with plans for expansion to other cities in Latin America including Monterrey (Mexico) and Mar del Plata (Argentina). As of 2024, the system reports over 2,500 users across 5 countries and 12 cities. The project is open source and designed to function as public infrastructure, allowing any organization to build services on top of the protocol without requiring special permissions.