Buenos Aires has introduced a new digital identity system that prioritizes privacy using zero-knowledge technology.

The Argentinian government has integrated QuarkID, a blockchain-based identity solution, into its miBA app, which offers services and documents to over 3.6 million residents, according to a press release from Chainwire.  

This initiative was launched on October 1, 2024 and marks Buenos Aires as the first city in the world to adopt ZK technology for managing decentralized digital identities.

Introducing QuarkID gives residents greater control over their personal data. The system allows them to manage documents like birth certificates and tax records through their mobile devices.

Buenos Aires and ZK technology

The key innovation here is zero-knowledge cryptography, which enables users to verify information without revealing unnecessary personal details. 

Zero-knowledge technology, a cryptographic tool, ensures privacy by allowing only relevant data to be shared during verification processes. In practical terms, this means personal data is protected from exposure during interactions, and no third party — including the government — can track how or when these credentials are used.

This differs from traditional systems, where institutions often manage and store users’ data.

The blockchain framework for QuarkID is built on the ZKsync Era blockchain, providing enhanced security and transparency. Since personal credentials are stored on a decentralized system, risks like data breaches and identity theft are reduced, according to the release.

Buenos Aires plans to expand the system to cover more documents, such as driver’s licenses and public permits.

QuarkID has also been piloted in Mexico, Colombia, and Peru, with further expansion planned across Argentina.