The memory pool bug caused empty transaction blocks in BCH, and P network has suspended deposits and withdrawals

This problem may be an operation count bug, where they are using the old rules to verify the operation count instead of verifying it according to the new rules.

Bitcoin Cash is currently the world's fourth-largest cryptocurrency with a market capitalization of more than $6 billion. A previous system-wide upgrade (also known as a hard fork) has split the Bitcoin Cash (BCH) network in two - but now, there are problems.

A user from the Reddit forum revealed that a code bug appeared in Bitcoin ABC, the software version developed by the Bitcoin Cash developer team, which quickly affected the Bitcoin Cash memory pool (mempool) that was unrelated to the upgrade itself. According to data disclosed by BitMEX Research's Forkmonitor tool, a chain split occurred just after the Bitcoin Cash network attempted to upgrade to the new software at block 582,679.

Similar to the Bitcoin blockchain, Bitcoin Cash also requires miners to verify transactions before adding new blocks to the blockchain. The memory pool usually contains all pending transactions on the Bitcoin Cash blockchain that are waiting for miners to approve. Reddit forum user "FerriestaPatronum" explained:

“It looks like there was a small bug in the mempool acceptance rules right after the Bitcoin Cash hard fork… From what I understand so far, the issue was probably an operation count bug where they were still using the old rules to validate the operation count instead of validating it according to the new rules.”

Just after the vulnerability appeared, Bitcoin Cash developers quickly released new code to fix the bug. According to data from CoinDance and information disclosed by industry insiders, before the bug was fixed, the Bitcoin Cash blockchain generated a string of empty transaction blocks.

Vin Armani, CTO of Bitcoin Cash application CoinText, said:

“About an hour and a half later, the block was cleared. Now the mempool is fine and transactions are entering the blocks as before, everything is back to normal.”

However, as of this writing, it is still unclear how many nodes (i.e., computer servers running the Bitcoin ABC software) have upgraded the software to fix the bug. In order to fix this problem, the cryptocurrency exchange Poloniex has announced that it will suspend Bitcoin ABC withdrawals and deposits. The exchange posted on Twitter:

“There is an issue with the Bitcoin Cash hard fork scheduled today, so we will be disabling deposits and withdrawals for BCHABC until further notice. The Bitcoin Cash core developers are working hard to resolve the issue, and we appreciate your patience.”

Or is it the problem of centralization?

According to the research and development team of Navier, a blockchain startup that operates mining and mining pools, most Bitcoin Cash miners currently use the Bitcoin ABC software instead of other Bitcoin Cash software such as Bitcoin Unlimited (BU).

David Steinberg, Vice President of Navier, explained:

“Most Bitcoin Cash miners were using the Bitcoin ABC client, not Bitcoin Unlimited, so people were creating transactions and submitting them to the mempool faster than they could write a block, which resulted in most of the blocks being empty.”

David Steinberg also emphasized that if miners can try to use different node software, it can effectively prevent the problem of blockchain network paralysis caused by code bugs. He added:

“Having a single type of node is a form of centralization — you can trust the codebase from your chosen node type to keep working as expected. Ideally, miners would try to choose different types of node software to prevent bugs like this from happening again.”

David Steinberg believes that using some particularly popular software during a hard fork is actually a dangerous thing. He concluded:

“The fact that this bug happened at the same time as a hard fork exacerbates the problem because normally you have to upgrade your node software to participate in a fork. For normal incremental upgrades, not every node will get the software updated in time, so if you try to use different node software, this problem may only affect a small number of miners. I think the biggest problem here is that programmers make mistakes, and even if it’s a decentralized system, if there is a centralized problem somewhere - such as relying on a single code base, a bug can cause the network to be affected.”

Original author: Christine Kim

Odaily Planet Daily Translator: Moni

This article is translated from CoinDesk (https://www.coindesk.com/bitcoin-cash-scheduled-hard-fork-tripped-up-by-software-bug).