Claim transaction

The claim command is where a production and consumption certificate "cancel" each other out.

To use the claim command one has to specify two slices, one production and one consumption, and they have to be of equal quantity because of proofs.

This might require one to perform some slice commands to make them fit together.

Once a claim has been created, it cannot be undone.

Example

In the example below 3 GCs exists, production-solar, production-wind and Consumption. A series of commands are then executed:

1. Slice Consumption to ConSlice-A and ConSlice-B
2. Slice Production-Solar to Slice-A and SliceB
3. Claim Slice-B to ConsSlice-A
4. Slice Production-Wind to Slice-C and SliceD
5. Claim Slice-C to ConsSlice-B

Privacy and Zero Knowledge proofs

As in the slice command, all quantities are hidden using Pedersen Commitments and Zero Knowledge proofs.

The Zero Knowledge proof can prove that the two pedersen-commitments in each slice are equal without revealing the actual numbers.

Multiple state changes on slices

Because of the nature of the ClaimCommand involving multiple GCs that can exists on any registry, the ClaimCommand happens in multiple steps involving first creating AllocatedEvents for the slices, before "committing" the ClaimedEvents to the slices. When the ClaimedEvent is persisted, the claim has completed. A "rollback" of AllocatedEvents are still on the drawing board.

sequenceDiagram
    actor user as Actor
    participant prod as Production Slice
    participant cons as Consumption Slice

    user ->> prod: Initiate ClaimCommand

    activate prod
    prod --) cons: Verify Slice exists
    prod --) prod: Verify Area and period are equal
    prod ->> prod: Create AllocatedEvent
    prod ->> cons: #
    deactivate prod

    activate cons
    cons --) prod: Verify allocation exists
    cons ->> cons: Create AllocatedEvent
    cons ->> prod: #
    deactivate cons

    activate prod
    prod --) cons: Verify allocation exists
    prod ->> prod: Create ClaimedEvent
    prod ->> cons: #
    deactivate prod

    activate cons
    cons --) prod: Verify Claimed
    cons ->> cons: Create ClaimedEvent
    cons ->> user: ClaimCommand Success
    deactivate cons