{ // message
  PROCESSING: {
		nonce: 12345...,
    recipient: Bob
  },
  AUTHZ: {
    signer: Alice,
    target: Lawyer
  }
}

1. Recipient in processing
- Avoid leakage of contacts via iterability
3. Remove recipient from `contextId`
- Avoid leakage of contacts via iterability
3. Move target to AUTHZ
- To store in different destinations
- Computed message/canonical ID remains the same even if AUTHZ is a different JWS
4. Nonce protects against iterability of signer DID.