NIP: 26

Delegated Event Signing

draft mandatory author:markharding author:minds

This NIP defines how events should be verified and signed to support generating events on behalf of someone else. It should be possible to sign Nostr events from other keypairs.

Another application of this proposal is to abstract away the use of the 'root' keypairs when interacting with clients. For example, a user could generate new keypairs for each client they wish to use and authorize those keypairs to generate events on behalf of their root pubkey, where the root keypair is stored in cold storage.

Introducing the 's' tag

This NIP introduces a new tag: s which is formatted as follows:

[
  "s",
  <signed pairing payload (base64 encoded)>,
  <signed pairing signature (64-bytes shnnorr signature of the sha256 hash of the signed pairing payload>
]

Signed Pairing Payload

The Signed Pairing Payload should be a base64 encoded JSON object as follows:

{
  "signerkey": <32-bytes hex-encoded public key of who is authorized to sign>,
  "created_at": <unix timestamp of issued time>,
  "expires_at": <optional, if present unix timestamp of invalidation time>
}

For example, the Signed Pairing Payload eyJzaWduZXJrZXkiOiI2MjkwM2IxZmY0MTU1OWRhZjllZTk4ZWYxYWU2N2NjNTJmMzAxYmI1Y2UyNmQxNGJhYmEzMDUyZjY0OWMzZjQ5IiwiY3JlYXRlZF9hdCI6MTY1OTQ0NjMxNX0= consists of the payload:

{
  "signerkey": "62903b1ff41559daf9ee98ef1ae67cc52f301bb5ce26d14baba3052f649c3f49",
  "created_at": 1659446315
}

Signed Pairing Signature

The Signed Pairing Signature is a schnorr signature of the sha256 hash of the Signed Pairing Payload. For example 2ed3e4b8470ce37b7e1946441a323d1d71c8a846fe49787ec406e14a44632cc96e48cabccc4a526eedd51aca33bf2a5cf7fb85462d23ad6d4de29c8b91abc41b is a signature of the payload mentioned above.

Modifying event verification

When the s tag is provided, events must be signed and verified by the respective private key of the signerkey. Clients/relays should confirm that no revocation have been created with a greater created_at value.

Clients must verify the token is valid. The token may include the expires_at field if it wishes the delegated signing to be temporary (ie. sign events for 2 hours, 7 days, etc).

TODO: How to revoke. This could be a future NIP.

Example

Below is an example of an event published by 62903b1ff41559daf9ee98ef1ae67cc52f301bb5ce26d14baba3052f649c3f49, on behalf of 86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e.

{
   "id":"23bf557814cd294d77a52e43d16903862c231857319f950ba40474fde1b9c393",
   "pubkey":"86f0689bd48dcd19c67a19d994f938ee34f251d8c39976290955ff585f2db42e",
   "created_at":1652969505,
   "kind":1,
   "tags":[
      [
         "s",
         "eyJzaWduZXJrZXkiOiI2MjkwM2IxZmY0MTU1OWRhZjllZTk4ZWYxYWU2N2NjNTJmMzAxYmI1Y2UyNmQxNGJhYmEzMDUyZjY0OWMzZjQ5IiwiY3JlYXRlZF9hdCI6MTY1OTQ0NjMxNX0=",
         "2ed3e4b8470ce37b7e1946441a323d1d71c8a846fe49787ec406e14a44632cc96e48cabccc4a526eedd51aca33bf2a5cf7fb85462d23ad6d4de29c8b91abc41b"
      ]
   ],
   "content":"Hello Nostr. This is Minds calling.",
   "sig":"30f0ebb907bd23416dd32a14b905abeb1db3fde97c74a151c51e5503e91ed25d58fbdcd95910ea4c11dc49d3fca8c616c0e7489e0f8da37b0938a7ce393285e7"
}

3.3 KiB Raw Blame History