Sidechains about catena

[pixelspark]

So in order to claim a reward in the 'superchain' for work on a sidechain, the miner should simply submit the same block to the superchain again. As this defeats the purpose of having side chains at all, we should find a way to exclude the payload from the block, but still have enough information to validate the block.

This could be done by online including a hash of the payload in the signature (like Bitcoin's merkle root), and then include only that signature in the 'light' block.

Also we'd need to add the genesis hash, so the superchain can distinguish between chains. The superchain also needs to be aware of the difficulty mechanism used in the sidechain. A 'light' block (which would be a superblock transaction, let's call them a 'claim') thus looks like this:

• Block version (8 B)
• Genesis hash for the chain (32 B)
• Previous block hash (32 B)
• Block height (8 B)
• Timestamp (8 B)
• Payload hash (32 B)
• Miner public key hash (32 B)
• Nonce (8 B)
• Signature (based on the above) (32 B)

(Total size is 192 bytes, which means a 1MB superblock can contain ±5k 'claims' We could shave a few bytes off by taking only 4 bytes for nonce and version, which would make the block 184 bytes).