1> __Warning__ `unrecommended`: adds unnecessary burden for little gain23NIP-264=======56Delegated Event Signing7-----------------------89`draft` `unrecommended` `optional` `relay`1011This NIP defines how events can be delegated so that they can be signed by other keypairs.1213Another 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. 1415#### Introducing the 'delegation' tag1617This NIP introduces a new tag: `delegation` which is formatted as follows:1819```json20[21 "delegation",22 <pubkey of the delegator>,23 <conditions query string>,24 <delegation token: 64-byte Schnorr signature of the sha256 hash of the delegation string>25]26```2728##### Delegation Token2930The **delegation token** should be a 64-byte Schnorr signature of the sha256 hash of the following string:3132```33nostr:delegation:<pubkey of publisher (delegatee)>:<conditions query string>34```3536##### Conditions Query String3738The following fields and operators are supported in the above query string:3940*Fields*:411. `kind`42 - *Operators*:43 - `=${KIND_NUMBER}` - delegatee may only sign events of this kind442. `created_at`45 - *Operators*:46 - `<${TIMESTAMP}` - delegatee may only sign events created ***before*** the specified timestamp47 - `>${TIMESTAMP}` - delegatee may only sign events created ***after*** the specified timestamp4849In order to create a single condition, you must use a supported field and operator. Multiple conditions can be used in a single query string, including on the same field. Conditions must be combined with `&`.5051For example, the following condition strings are valid:5253- `kind=1&created_at<1675721813`54- `kind=0&kind=1&created_at>1675721813`55- `kind=1&created_at>1674777689&created_at<1675721813`5657For the vast majority of use-cases, it is advisable that:581. Query strings should include a `created_at` ***after*** condition reflecting the current time, to prevent the delegatee from publishing historic notes on the delegator's behalf.592. Query strings should include a `created_at` ***before*** condition that is not empty and is not some extremely distant time in the future. If delegations are not limited in time scope, they expose similar security risks to simply using the root key for authentication.6061#### Example6263```64# Delegator:65privkey: ee35e8bb71131c02c1d7e73231daa48e9953d329a4b701f7133c8f46dd21139c66pubkey: 8e0d3d3eb2881ec137a11debe736a9086715a8c8beeeda615780064d68bc25dd6768# Delegatee:69privkey: 777e4f60b4aa87937e13acc84f7abcc3c93cc035cb4c1e9f7a9086dd78fffce170pubkey: 477318cfb5427b9cfc66a9fa376150c1ddbc62115ae27cef72417eb95969139671```7273Delegation string to grant note publishing authorization to the delegatee (477318cf) from now, for the next 30 days, given the current timestamp is `1674834236`.74```json75nostr:delegation:477318cfb5427b9cfc66a9fa376150c1ddbc62115ae27cef72417eb959691396:kind=1&created_at>1674834236&created_at<167742623676```7778The delegator (8e0d3d3e) then signs a SHA256 hash of the above delegation string, the result of which is the delegation token:79```806f44d7fe4f1c09f3954640fb58bd12bae8bb8ff4120853c4693106c82e920e2b898f1f9ba9bd65449a987c39c0423426ab7b53910c0c6abfb41b30bc16e5f52481```8283The delegatee (477318cf) can now construct an event on behalf of the delegator (8e0d3d3e). The delegatee then signs the event with its own private key and publishes.84```json85{86 "id": "e93c6095c3db1c31d15ac771f8fc5fb672f6e52cd25505099f62cd055523224f",87 "pubkey": "477318cfb5427b9cfc66a9fa376150c1ddbc62115ae27cef72417eb959691396",88 "created_at": 1677426298,89 "kind": 1,90 "tags": [91 [92 "delegation",93 "8e0d3d3eb2881ec137a11debe736a9086715a8c8beeeda615780064d68bc25dd",94 "kind=1&created_at>1674834236&created_at<1677426236",95 "6f44d7fe4f1c09f3954640fb58bd12bae8bb8ff4120853c4693106c82e920e2b898f1f9ba9bd65449a987c39c0423426ab7b53910c0c6abfb41b30bc16e5f524"96 ]97 ],98 "content": "Hello, world!",99 "sig": "633db60e2e7082c13a47a6b19d663d45b2a2ebdeaf0b4c35ef83be2738030c54fc7fd56d139652937cdca875ee61b51904a1d0d0588a6acd6168d7be2909d693"100}101```102103The event should be considered a valid delegation if the conditions are satisfied (`kind=1`, `created_at>1674834236` and `created_at<1677426236` in this example) and, upon validation of the delegation token, are found to be unchanged from the conditions in the original delegation string.104105Clients should display the delegated note as if it was published directly by the delegator (8e0d3d3e).106107108#### Relay & Client Support109110Relays should answer requests such as `["REQ", "", {"authors": ["A"]}]` by querying both the `pubkey` and delegation tags `[1]` value.111112Relays SHOULD allow the delegator (8e0d3d3e) to delete the events published by the delegatee (477318cf).