# Identity

Centralized identities are tied to a single service. Decentralized identity is not.

We will call entities with identities "actors", because non-human entities such as companies, organizations, and bots may have identities on a social network.

Identity allows an actor to:

- control an account and access private data
- communicate with another actor
- establish visible reputation and credibility

Desirable qualities for decentralized identities:

- Allow authentication and migration between services
- Allow communication across services
- Unique, global, and memorable

## Decentralized Identity

OAuth is currently the most successful identity standard. OAuth was created to securely transfer user credentials from one site to another. OAuth identity providers became centralized because users could not run or choose their own identity providers.

### Identity in federated applications:

- email
- XMPP
- Matrix
- Diaspora: User identities in Diaspora are tied to their pod, and cannot be migrated. Diaspora uses the Webfinger protocol to discover users from other pods. User information is returned via hCard, an open microformat standard for identity.
- Mastodon:
- Solid

### Identity in p2p applications:

P2p systems key management, key verification, key backup. Account recovery.

- IPFS
- Peergos
- Hypercore
- Gun
- Ssb
- Aether
- Iris

### Blockchain identity

- Namecoin
- Handshake

Lots of them.
Microsoft
IBM

### Decentralized Identifiers (DIDs)

[DIDs](https://w3c-ccg.github.io/did-primer/) are a new type of globally unique identifier that do not require a centralized registration authority, and can serve as a decentralized public key infrastructure. DIDs are a [W3C standard](https://www.w3.org/TR/did-core/).

The format of a DID is: a scheme identifier, followed by the DID method, followed by a method-specific identifier. A simple example: `did:example:123456789abcdefghi`

## Reputation & Trust

Web-of-trust

P2p network can ban, but cannot take away identity

## Social graph proof

- Handshake problem and collusion protection (see IRIS)

## Fail cases

Account recovery.
Sybils and spam
Impersonation

## Links

- [What are Decentralized Identifiers](https://www.evernym.com/blog/what-are-decentralized-identifiers-dids/)
- [Decentralizing the Social Web](https://hal.inria.fr/hal-01966561/document)