Key Schedule Record

PAGE STATUS: early draft

A key schedule record lists subkey information and revocation information for a master key.

A key schedule record has kind 0x1.

A key schedule record MUST be considered invalid if it does not conform to this specification.

A key schedule record MUST be considered invalid if the signing key and the master key are not identical.

Tags

Every subkey listed in a key schedule record must have an associated subkey tag listing the subkey.

Payload

The payload is not human readable.

`The payload contains a sequence of 40-byte subkey records laid out as follows:

            1   2   3   4   4   5   6
    0   8   6   4   2   0   8   6   4
 0  +-------------------------------+
    | SUBKEY    1/4                 |
 8  +-------------------------------+
    | SUBKEY    2/4                 |
 16 +-------------------------------+
    | SUBKEY    3/4                 |
 24 +-------------------------------+
    | SUBKEY    4/4                 |
 32 +-------------------------------+
    |MARKER|RES|REVOC TIMESTAMP     |
    +-------------------------------+

[0:32] - SUBKEY is the 32-byte subkey

[32:33] - MARKER is 1-byte and is one of the following

  • 0x0 - ACTIVE_SIGNING_KEY - A Mosaic ed25519 signing key (subkey) in current use
  • 0x1 - ACTIVE_ENCRYPTION_KEY - A Mosaic X25519 encryption key in current use
    • These keys are used for receiving encrypted data only, not for signing.
    • Generally the secretkey for encryption is distributed to every device that needs the ability to view encrypted data. Being a separate subkey from the signing keys, it limits the damage from compromise.
  • 0x40 - REVOKED_ALL - All records signed by the key are to be considered invalid.
  • 0x41 - REVOKED_PAST - Records signed by the key that were received prior to the revocation timestamp (based on when it was received by software and NOT based on the date inside of the record) are still considered valid; however, records either received after the revocation timestamp, or with a timestamp after the revocation timestamp, are considered invalid.
  • 0x4F - OUT_OF_USE - Key is no longer in use (but nothing is revoked). This may be used for signing keys or encryption keys.
  • 0x80 - ACTIVE_NOSTR_KEY - A nostr secp256k1 subkey
    • This helps support dual-stack software that works with both nostr and Mosaic.

[33:34] - RES is 1-byte and is reserved. It MUST be 0.

[34:40] - REVOC TIMESTAMP is 6-bytes and is in the format described in timestamps. Timestamp is required for REVOKED ALL and REVOKED PAST. Timestamp is suggested for OUT_OF_USE. Timestamp SHOULD be zeroed in all other cases.

Server Used

These are posted to all of the author's Outbox servers.