nips/103.md

NIP-103
=======

Direct Message Envelopes
------------------------

`draft` `optional` `author:threeseries`

This NIP defines a kind 16 event which is a kind 4 event (see [NIP-04](04.md) where the decrypted content is itself a kind 4 event.

# Motivation and usage

It's well-known that direct message metadata is public on nostr since everyone can see who is messaging whom and when. One solution to this problem is for the entire event including its metadata to be encrypted before being sent. This outer event can be encrypted and signed with a random key pair, thus hiding the true sender of the direct message. On receiving a kind 16 event the client should decrypt both the outer and inner content, displaying the decrypted inner content to the recipient.

# Example:

A kind 4 event:

```json
{
  "id": "67264df8e079a7cf52f81b912debb4e47550743f1f4a5f170407f83bc9dbc12b",
  "pubkey": "6475c0ba9c8f5f45dcfdae553189d1b8d089118295ba5b902c0a698e192f535b",
  "created_at": 1682886605,
  "content": "z2HVzkQXJAJSqebsnrkNWg==?iv=O0pf3XLsEkOo+G+/QosxDg==",
  "kind": 4,
  "tags": [
    [
      "p",
      "208404de380e7c02c366cc667ae9e969d687ec7a3c03aacd364c4716a2e72327"
    ]
  ],
  "sig": "1626034f09101c120f968ef1da14dd23e4e4b14db22227737ad717cc9033188e0426cf0993a0c776b8a5156ef6ece939f50f575ce294b9689864b46f49b5e8c6"
}
```

After wrapping in kind 16 with a random key pair:

```json
{
  "id": "b8b50e4c63102e5c737186e7ed7c23741aea34a7743ea27a41e6a18654261818",
  "pubkey": "4c34b0fb27f79d376456f95391b1b43173d890d3e08558fe1e0f56cea59af52a",
  "created_at": 1683293572,
  "content": "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?iv=FT7fwoP8pjjE97MUO9J8nA==",
  "kind": 16,
  "tags": [
    [
      "p",
      "208404de380e7c02c366cc667ae9e969d687ec7a3c03aacd364c4716a2e72327"
    ]
  ],
  "sig": "ea7a1c500e2ebd3a1985777874c66d8fb21d1ae3d2ed5ed643ff7a60d42152923c5545794dac5b30d8ac51327812afb3c7c76c7616165dc92fe0040a2aa5bf12"
}
```