I don't like the empty blocks in our blockchain created by the Hathor Network merge-miner. There is, however, a bonus by the blocks themselves that we can all agree on and it's that it speeds up confirmation times.

The Blockchain

The blockchain system was created by Satoshi Nakamoto as a replacement for the middleman system that all modern payment systems use back in 2009. The basis for it is that CPUs would "mine" a hash that contains the previous block's hash plus all the unmined block's transactions, and when a match is made, the block is propagated through the node network. Any block after the block that was just made will "confirm" the block. Satoshi then called out that the most secure number of confirmations a block can get is 6 blocks. Because we take his words to heart sometimes, this allowed alternate chains to break apart as Bitcoin software recognizes the longest chain as it's harder to mathematically compute more blocks than the actual chain— i.e. the chain with more than 6 blocks/confirmations.

The Empty Blocks

A block can be considered empty when it contains no transactions at all except for its first transaction called a coinbase transaction. These blocks aren't generally helpful but they can speed up confirmation in a small margin.

The negative side of empty blocks is the propagation and confirmation of actual transactions themselves as since these transactions aren't in the next possible block possible, they are still unconfirmed, which can lead to a higher possibility of a double-spend.

The Decision to Create

To mine an empty block, the mining software requires users to know if they can do so with their node of choice, or the mining pool's capabilities, essentially to create an empty block you need to be able to create a block without accepting any transaction. If you were able to as mining software these days connect to pools, and these pools are essentially merging all hashes you will submit into a node that they use.

Pro and Con

One thing you can get with empty blocks is that you virtually own the block reward you get there, however you will only get the block reward and only the block reward during that block. It also may or may not reveal yourself to other interested parties, but that is unconfirmed business.

Hathor

This article was created during a time where the Hathor Network revealed itself to the BCH community by mining empty blocks. People were suspicious, of course. Smart contracts that rely on the propagation of new blocks such as Mistcoin mining would hiccup and mine two times to compensate for the empty block. Other people would discuss to themselves what it can mean for the community, but as of finalizing this article, the Hathor miner has no longer mined empty blocks, and there had been confirmed four miners, one of which was the empty-block Hathor miner.

Conclusion

Having empty blocks can be good protection in the short-term, but it will collect the unconfirmed transactions until the mempool of the whole node network gets full, so it is not really advised. We were merely lucky that someone had tried doing it, and hopefully, they enjoyed the BCH they mined.