Self-Sovereign Identity: DIDs, VCs & Credo TS Explained

Self-Sovereign Identity (SSI) gives individuals control over their own digital identity, eliminating dependence on centralized providers like Google, Amazon, or Facebook. Instead of passwords stored by third parties, SSI uses cryptographic keys and Decentralized Identifiers (DIDs) that the user owns.

TL;DR: SSI is moving from concept to production. Hyperledger Aries was archived in April 2025 as its components matured into independent projects — Credo TS at the OpenWallet Foundation now supports OpenID4VC, SD-JWT-VC, and mDL credentials. The EU mandates digital identity wallets for all citizens by September 2026.

What is a Decentralized Identifier (DID)?

A DID is a globally unique identifier that the user owns and controls, without relying on any central authority. It reveals nothing about the user by default — identity claims are shared selectively through Verifiable Credentials.

With SSI, you have a Decentralized Identifier (DID) that reveals nothing about the user. The simplest DID is a public key encoded string like:

did:key:<public_key>

You prove your identity by signing data with your private key, using Public Key Infrastructure. DIDs are stored in your digital wallet.

Using DIDs, you can receive Verifiable Credentials (VCs) — cryptographically signed certifications issued by a trusted authority. A common use case is a university degree: instead of a paper diploma or PDF (which can be forged), the university signs the credential with their private keys, making forgery practically impossible.

What happened to Hyperledger Aries?

Hyperledger Aries was archived in April 2025, but this was a sign of maturity, not abandonment. Its components graduated into independent projects at the OpenWallet Foundation and Decentralized Identity Foundation.

Hyperledger Aries was the umbrella project for decentralized identity frameworks. In April 2025, the maintainers requested it be archived as its components had matured into independent projects:

Credo TS: Current State

Credo TS (v0.5.x stable, v0.6 in alpha) is a Growth-stage project at the OpenWallet Foundation. Key features in v0.5:

• OpenID4VC: Full OpenID4VCI, OpenID4VP, and SIOPv2 support for issuance, presentation, and verification
• SD-JWT-VC and mDL/mDOC: Selective disclosure credentials and mobile driver's license format
• X.509 certificates: Support alongside DIDs
• Aries Askar: Replaced the deprecated Indy SDK for secure storage
• AnonCreds as W3C VCs: Anonymous credentials compatible with W3C standards
• Platform support: Node.js and React Native

Supported DID methods include:

did:web

did:webvh

did:key

did:jwk

did:peer

did:sov

did:indy

did:cheqd

did:hedera

What wallets support Verifiable Credentials?

Several production-grade wallets are available:

• Paradym Wallet by Animo — built on Credo TS, available for iOS and Android
• BC Wallet — by the Government of British Columbia, built on Credo TS
• EasyPID Wallet — German Federal Agency (SPRIN-D) prototype EUDI Wallet, built on Credo TS
• Ireland gov.ie Digital Wallet — OGCIO pilot using Credo TS with OpenID4VC and SD-JWT
• Sphereon Wallet — built on Veramo

Running in the Browser

You can also run Credo TS in the browser. Watch the following meetup on YouTube or access the repository on Github:

What is the EU doing about digital identity?

The EU mandates that all member states provide a European Digital Identity (EUDI) Wallet to citizens, residents, and businesses by September 2026 under the eIDAS 2.0 regulation. This is the largest government-driven adoption of verifiable credentials globally.

The EU's eIDAS 2.0 regulation (entered into force May 2024) is driving massive adoption of verifiable credentials:

• September 2026: All EU member states must provide a EUDI Wallet to citizens, residents, and businesses
• December 2027: Banks and financial institutions must accept EUDI Wallets
• The DC4EU pilot tested cross-border credentials with 101 partners across 25 countries, achieving a 70% first-attempt success rate across 12 member states
• The Architecture Reference Framework (ARF) v2.4.0 was published in January 2026

New OWF lab projects in 2025 — DCQL TS, OpenID Federation TS, and OpenID4VC TS — further strengthen the open-source SSI ecosystem.

Related Posts

• Verifiable Credentials in Education — VCs for diplomas and micro-credentials
• How I built certifyme.id in 4 days using AI — Building a decentralized certification platform
• What is Hyperledger Fabric? — Enterprise blockchain for identity and supply chain

References

1. Credo TS on GitHub — Source code and documentation
2. OpenWallet Foundation — Credo 2025 Blog — Releases 0.5 and 0.6 overview
3. LF Decentralized Trust — Aries Project — Archive announcement and component mapping
4. European Commission — EUDI Wallet — eIDAS 2.0 regulation
5. DC4EU — Digital Credentials for Europe pilot
6. 3CL Foundation — Beyond DC4EU Report — Pilot results and policy recommendations