NIP-22
======

Key Migration
-------------

`draft` `optional`

Kind 18 informs the network that the owner of the pubkey is migrating to a new key. The event MUST contain a single `p` tag with the new pubkey owner will be using. 

```js
{
  "kind": 18,   
  "tags": [
    ["p", "<pubkey>", "<relay_url>"],
  ],
  "content": "<comment to followers>"
  //...
}
```

`Kind:18`s suggestion to move to a new key **alone** can't be trusted because the owner's keys might have leaked. It MUST be verified by Web of Trust.  

Close acquaintances to the owner should verify the intention off nostr and signal their assessment of the owner's intentions by following the new key. Others can follow based on their individual trust on such those acquaintances.

## Interpretation

The presence of one or more `kind:18`s, no matter who writes it, declares the key to be out of use, unreliable, unsafe and potentially stolen: No event, past and future, from this key can be trusted anymore.  

Users that have a `kind:18` published by their keys MUST migrate to a new key. 

There can be multiple `kind:18`s pointing to separate keys. Finding which event is the right one requires observing contact lists of trusted keys.

## Information retention

Clients SHOULD send `kind:18` to as many relays as possible, not only to the owner's relay list.  

Relays and Clients MUST reject Event Deletion ([NIP-09](09.md)) requests of `kind:18`s.

Clients SHOULD use Generic Repost (`kind:16`) with a stringified version of the `kind:18` and a `k` tag to `18` to let users warn followers and guarantee `kind:18`'s retention as much as possible.

Generic Re-posts events simply warn followers and MUST NOT be considered the user's final decision on which key to switch to. Contact lists are the only source of verification.  

## Client Behavior

Upon receiving a new `kind:18`, Clients MUST warn their user the pubkey is unsafe. 

Clients SHOULD offer ways to investigate and verify if: 
1. the transition to a new key was intended by the owner OR 
2. if this is an attack and the new key is controlled by an attacker.

Clients MAY download follow lists of the user's contact lists and display when a follow has switched to a new key. 

It's ok to delay verification until trusted keys start informing their assessments.

Upon verification, Clients SHOULD offer transition to the new key by: 
1. Changing the contact list accordingly
2. Changing any NIP-51 list accordingly 
3. Adding the old key to the Mute List