The Bitcoin mining pool Ocean has come under scrutiny over allegations of transaction censorship. Developer Kruw accused a miner of excluding his transaction in block 973,817, resulting in transaction fees 7.68% lower than the expected template.
According to Kruw, Ocean miner Powre excluded his merge transaction.
- Kruw accuses Ocean miner Powre of excluding his merge transaction in Bitcoin block 973,817.
- The comparison he shared shows that transaction fees are 7.68% lower than the expected block template.
- Coinjoined Chris defends miners' right to autonomously select transactions via Ocean's DATUM.
- Kruw believes that mining pools should not accept jobs that intentionally sacrifice participants' fee income.
Kruw initiated this debate on X on October 30, sharing a block comparison image and calling on Ocean's Coinjoined Chris to weigh in. The two sides subsequently clashed over whether mining pools should enforce transaction fees when individual miners independently decide which transactions to include.
Chris stated that he supports CoinJoin and wants miners to charge economically attractive fees, but opposes controlling miners' choices through pool payments.
Block comparison sparks allegations of censorship
In the original post, Kruw referred to the miner as "Powre" and described the excluded transfer as his merge transaction.
He wrote: "My merge transaction was censored by OCEAN miner 'Powre' in block 973,817."
The comparison chart he attached shows that the expected block contained 3,580 transactions, while the actual block contained only 1,698. The block weight shown in the chart decreased from approximately 3.99 million weight units to 2.93 million, with the rounded transaction fees being 0.017 BTC and 0.016 BTC, respectively.
The fee comparison shows a difference of 7.68%. Kruw believes that the uncollected fees harmed the interests of other participants in the pool and described the block as "partially emptied."
His allegations target transaction fee revenue. The percentages shown in the chart are not a measure of the entire block reward, nor do they indicate that each participant's earnings decreased by 7.68%.
The highlighted transaction in the screenshot has a fee of 223 satoshis, with a displayed rate of 0.15 satoshis per virtual byte. The diagram labels it as a consolidated transaction and shows it was first seen 4 minutes before block inclusion.
Although discussions frequently mentioned CoinJoin and financial privacy, Kruw's original post explicitly labeled this transfer as a coinjoin transaction.
Ocean's DATUM defense focuses on miners' choice rights
Regarding this complaint, Chris stated that Ocean’s DATUM setting allows miners to construct their own block templates. Some miners prioritize transactions with the highest available fees, while others follow their own transaction filtering policies.
He defended this decision-making authority, even though he did not agree with the final outcome.
Chris wrote: "I am a strong supporter of CoinJoin; I believe financial privacy is fundamental to Bitcoin, and we should strive to promote it as much as possible."
He agreed that waiving transaction fees is economically questionable, especially when this revenue could benefit participants in Ocean's payment system, TIDES.
However, Chris stated that mining pools should not decide which valid transactions individual miners must include. He believes that enforcing transaction selection policies at the pool level would undermine the control that DATUM grants to miners.
In a subsequent reply, he directly addressed the payment issue.
TIDES will reward the contributed computing power according to our payment rules, not based on whether OCEAN recognizes a miner's transaction selection.
Chris stated that he would like blocks to include more CoinJoin, PayJoin, and anchor transactions. He opposes miners forcing these preferences through payment decisions.
Kruw believes the payment mechanism can enforce fee collection.
Kruw fails to distinguish between transaction selection and pool control, arguing that Ocean can reject jobs with fees below its acceptable threshold.
He suggested that mining pools could respond to templates with lower fees with "Rejected share, check mempool connectivity" instead of paying miners.
The rejection mechanism he proposed is one of his arguments regarding how Ocean should handle this matter.
Chris questions whether there exists a universally accepted standard for the "correct" total fee amount. He says that different nodes may receive transactions at different times, employ varying relay strategies, or see transactions that other miners have never encountered.
He wrote: "A block fee that is 7.68% lower than a hypothetical maximum does not, by itself, prove that censorship is occurring."
He also questioned who should set acceptable thresholds, citing 99% and 95% as examples, and pointed out how mining pools handle private transactions, propagation delays, and reasonable variations between different mempools.
When Chris described this practice as rejecting previously valid work and withholding payment, Kruw explicitly endorsed this approach based on centralized profitability checks.
He replied: "Allowing miners to create their own templates exists solely so they can include additional profits that a central authority might overlook."