Technical Foundations

Self-Sovereign Identity (SSI) relies on a blend of innovative technologies to empower user control and decentralize identity management. Here’s a breakdown of the key innovations that make self-sovereign identity possible:

Blockchain Technology: Blockchain plays a crucial role in SSI. It provides a tamper-proof ledger for recording critical events like the issuance and ownership of Verifiable Credentials (VCs). Imagine a public registry where everyone can verify the authenticity of a credential without relying on a central authority. Transactions on the blockchain are secured through cryptography, making it highly resistant to tampering or fraud.

Public-Key Cryptography: This creates a key pair — a public key for sharing information and a private key for secure access. VCs are typically signed with the issuer’s private key, and anyone can verify the signature using the corresponding public key. This ensures the authenticity of the credential.

Digital Signatures: Similar to signing a physical document, digital signatures provide cryptographic proof that a specific entity (e.g., university) issued a VC. This allows relying parties (e.g., employers) to trust the information without contacting the issuer directly.

Hash Functions: These are one-way mathematical functions that transform data into a unique fingerprint. Any change to the data will result in a completely different hash, making it easy to detect alterations. Hash functions are used to ensure the data within a VC hasn’t been tampered with.

Decentralized Identifiers (DIDs): Imagine a unique web address for your identity, not tied to any specific platform or service provider. DIDs provide this functionality. They are globally unique, user-managed identifiers, offering greater control over how their identity is represented online.

Verifiable Credentials (VCs): These are tamper-proof digital documents containing a user’s verifiable claims about themselves, such as educational qualifications or work experience. VCs are issued by trusted entities (e.g., universities) and stored securely in the user’s digital wallet. When needed, users can selectively share specific VCs with third parties for verification. Cryptographic proofs are used to demonstrate the validity and authenticity of the credential without revealing any unnecessary underlying data.

This combination of technologies empowers users to control their identity data, securely share verified credentials, and interact online with greater trust and transparency.