Status: Draft
Mandatory: Yes
Author: Melvin Carvalho

Table of Contents

  1. Introduction
  2. Encoding Formats
    1. Nostr Public Key
    2. Npub System
    3. DID URI
  3. Usage in Signed Events and Headers
    1. Authentication Header
    2. Nostr Header


This specification provides an overview of the globally unique identity representation in the nostr system. We will discuss various encoding formats and their usage in different scenarios.

Encoding Formats

Nostr Public Key

A nostr public key is the raw hex-encoded public key that serves as a globally unique identifier for an entity in the nostr system.

Npub System

The npub system is an alternative encoding format that represents a nostr public key. It provides a compact and efficient representation of the unique identifier. Npub uses bech32 in the front end to encode a key.


A Decentralized Identifier (DID) URI is another equivalent form that can be used to represent a nostr public key. It is a self-sovereign and decentralized identity solution that offers better interoperability with other identity systems.

Usage in Signed Events and Headers

The identity encoding formats can be utilized in various ways, such as in signed events or specific headers, to verify the identity of an entity.

Authentication Header

The raw hex-encoded public key is often sent within a signed event via the Authentication header. This enables the receiver to verify the identity of the sender.

Nostr Header

Identity information may also be sent using the nostr: header. This method provides an alternative way to transmit identity information, while maintaining flexibility in choosing the preferred encoding format.