BTC.Top, a popular cryptocurrency mining pool, has recently hit a high of 54% of Bitcoin Cash’s hashrate, before seeing it recede. According to some users the mining pool has just been going after profitability, although any pool having over 51% of the hashrate could be cause for concern.
According to data from Coin.Dance, BTC.Top managed to mine over 54% of the blocks on the Bitcoin Cash network for a brief period of time, before seeing its hashrate go down. At press time, data shows in the last 24-hour period it mined 47% of blocks on the network.
— 損 (@HappyStopLoss) May 18, 2019
Having over 51% of a network’s hashrate is seen as negative by many, as it could allow the entity controlling the majority of, in this case Bitcoin Cash’s hashrate, to pull an attack on the blockchain and double-spend coins.
This essentially means every network participant is forced to trust the mining pool not to attack Bitcoin Cash. Notably, BTC.Top is believed to have recently thwarted an attack on the network that sought to steal coins someone sent to a Segregated Witness (SegWit) address on the Bitcoin blockchain.
The block prior to the reorg already had normal transactions.
This was a second -independent- deliberate attack.
An attempted robbery or reputational attack.
— Javier González González (@JavierGonzalez) May 16, 2019
As such, network participants seemingly trust the mining pool was only mining the most profitable cryptocurrency on the SHA-256 algorithm, and wasn’t trying to act maliciously. This, however, doesn’t mean it couldn’t.
Various cryptocurrencies have suffered 51% attacks in the crypto space’s short history, including Verge (XVG), Bitcoin Gold (BTG), and Ethereum Classic (ETC). ETC suffered one of the most notable attacks, as hackers compromised one of the most popular networks in the space to double-spend coins worth over $1.1 million.
While BTC.Top heavily mines Bitcoin Cash, it revealed back in November of last year, before the hard fork that created Bitcoin Satoshi’s Vision (BSV) occurred, that it was apolitical and would support the blockchain with the most hahspower.
At the time Jiang Zhouer, the Chinese cryptocurrency mining pool’s founder, revealed BTC.Top’s goal was to recover stability for Bitcoin Cash, which at the time was engaged in a “war” between two sides.
On BSV’s side there are also concerns about a potential 51% attack. As covered, CoinGeek has reached the necessary hashrate to attack the network more than once, but hasn’t done anything malicious.