Increasing the size of blocks in a blockchain is a potentially counterproductive decision for the stability of Bitcoin as it can compromise the security and decentralization of the entire network, explained Lucas Nuzzi Director of Technology Research at Digital Asset Research.
According to the technology expert, the upgrades proposed by members of the Bitcoin Cash community do not represent a real breakthrough and are nothing more than temporary solutions that do not solve Bitcoin’s scalability problem.
In an article named “The resolution of the Big Block experiment” published in his personal blog, Nuzzi makes a kind of historical journey about the reasons that led to the fork that originated the birth of Bitcoin Cash.
In it, he explains that before its definite disappearance, Satoshi Nakamoto himself spoke against sudden increases in block size warning a user that if he implemented a patch with these characteristics, he would do it “to his own detriment.” For Satoshi the increase in the size of a block had to be done when it was absolutely necessary if the current capacity of a block was not enough anymore:
“It can start being in versions way ahead, so by the time it reaches that block number and goes into effect, the older versions that don’t have it are already obsolete.
Note that Satoshi was not opposed to the idea; however, he mentioned that this increase should be gradual and as little as possible. For Satoshi, it was not necessary to have a blocksize able to support a number of transactions similar to that of PayPal (as some users proposed) if the number of continuous transactions that would allow filling that quota did not exist at that time.
For Mr. Nuzzi, solutions such as Lightning Network or Liquid represent a technological advance.
“Larger blocks reduce fees, increase the supply of block space, and make a fee market more difficult to develop. On the other hand, if we assume that most transactions will take place on Lightning channels or Liquid sidechains, only large value transactions would take place on-chain, which is a model that makes a robust fee market more feasible.”
Below is an excerpt of 3 reasons why Nuzzi considers that the Bitcoin Cash proposal is not a “viable long-term solution” to the Bitcoin problem:
1. They are a temporary solution:
“Block size increases are seen as a vertical scalability solution because they do not circumvent the requirement for all nodes to process all transactions canonically …
Mere block cap increases only solve the problem up until the cap is hit and, as such, are a temporary solution.”
2. Bigger blocks are hard to propagate
“A 128MB block would be extremely onerous to propagate to other nodes, even using more efficient propagation technologies like Graphene, which further introduces centralization to the system. As a result, miners would produce a much higher rate of orphan blocks, which are valid blocks that fail to be amended to the chain because they were not propagated fast enough. Hence, the chain would have to reorganize more often, which opens up the potential for double-spend attacks.”
3. Less nodes decrease network security
“128MB blocks every 10 minutes which are full, will result in 18.4GB of data a day, 129GB a week, and 0.5TB a month … Under 128MB blocks, power users would not be able to run a full node and it would be very expensive, even for corporations, to do so using cloud computing. The current directory size of the Bitcoin blockchain is 190GB, which enables most personal computers to run the software. However, if blocks double in size, Bitcoin’s directory size will grow at a proportional rate, increasing users’ storage costs. Consequently, less users will be able to run full nodes thereby potentially increasing miner centralization, contradicting Bitcoin’s ethos of decentralization.”