> ## Documentation Index
> Fetch the complete documentation index at: https://docs.soverage.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Key Concepts

> Core building blocks: DIDs, Verifiable Credentials, Personhood Tokens, attestations, and scores

## Decentralized Identifier (DID)

A globally unique, self-sovereign identifier anchored on-chain. The user owns and controls their DID. No central authority can revoke or modify it.

Each DID is published to its own consensus topic, making it independently resolvable by anyone. DIDs follow the [W3C DID specification](https://www.w3.org/TR/did-core/) and serve as the foundation for all Soverage credentials.

Format: `did:hedera:testnet:z6Mk...`

## Verifiable Credential (VC)

A [W3C Verifiable Credential](https://www.w3.org/TR/vc-data-model/) is a cryptographically signed digital proof. It contains:

* The user's DID
* Their personhood score at the time of issuance
* Completed attestation types
* A cryptographic proof ([Ed25519](https://datatracker.ietf.org/doc/html/rfc8032) signature)
* A commitment hash linking to on-chain attestations

VCs are issued via the [OID4VCI](https://openid.net/specs/openid-4-verifiable-credential-issuance-1_0.html) protocol and can be verified by any compatible system without contacting Soverage.

## Personhood Token

A non-transferable token minted on-chain.

* **One per person**: maximum supply of 1 per verified user
* **Non-transferable**: bound to the original wallet
* **On-chain**: publicly verifiable on the ledger
* **Minimal metadata**: wallet reference, personhood score, verification flag. No PII.

## Personhood score

A value from 0 to 100 reflecting the strength of the user's identity proof, based on the number and type of attestations completed.

## Attestations

Independent verification signals that build the user's identity profile:

| Type           | Method                                                          |
| -------------- | --------------------------------------------------------------- |
| Document (KYC) | AI-powered document analysis                                    |
| Email          | One-time code verification                                      |
| Phone          | SMS code verification                                           |
| Device         | [WebAuthn](https://www.w3.org/TR/webauthn-2/) passkey/biometric |
| Social account | OAuth (e.g. Google)                                             |

Each attestation generates a cryptographic commitment (one-way hash) and is recorded on-chain. The original data (document image, email address, phone number) is discarded after verification. New attestation types may be added over time.

## Cryptographic commitments

Personal data is never stored. Instead, Soverage generates one-way hashes (commitments) that prove a verification occurred without revealing what was verified. This enables selective disclosure: users can prove claims about their identity without exposing the underlying data.

All commitments are recorded on-chain and can be independently verified on any block explorer.