sgID

sgID is a privacy-focused digital identity system developed by Open Government Products, a unit within Singapore's GovTech Agency, launched in 2020. The system implements a privacy-preserving version of the OpenID Connect protocol that allows Singapore residents to authenticate and share government-verified data with third parties while maintaining control over their personal information.

Key technical features include:

• Zero-knowledge protocol implementation where user data remains encrypted end-to-end
• Unique identifiers generated for each service provider to prevent cross-site tracking
• Integration with OAuth 2.0 authorization code flow
• Selective disclosure capabilities allowing users to choose which data to share
• Government-verified data sourced from Singapore's national digital identity platform Singpass

The system has seen notable adoption within Singapore's public sector, with implementations in the National Health Appointment System and FormSG. sgID is available free of charge and provides SDKs for integration in both TypeScript/JavaScript and Python. While marketed as having Self-Sovereign Identity characteristics due to its privacy features and user control aspects, the system remains centrally managed by the Singapore government rather than being fully decentralized.