F2Pool Identified as First Bitcoin Mining Pool to Filter Transactions: Report

A fundamental aspect of Bitcoin’s appeal lies in its status as a form of currency resistant to censorship and immune to arbitrary regulations. The principle is that anyone with the means to cover network fees should be able to engage in transactions without requiring permission.

However, a new report suggests that a major Bitcoin mining pool filtered transactions based on sanctions imposed by the US Office of Foreign Assets Control (OFAC).

Asian-Based Bitcoin Mining Pool First to Comply With US Sanctions

According to 0xB10C – a pseudonymous Bitcoin developer and owner of a project called “miningpool-observer” – F2Pool became the first Bitcoin mining pool to filter transactions based on the OFAC sanctions.

The miningpool-observer tool identified six Bitcoin transactions originating from addresses subject to OFAC sanctions that were not included in blocks. It’s important to note that the two transactions absent from the mining pool ViaBTC and Foundry USA pool blocks are considered false positives and were not intentionally filtered.

On the contrary, the four OFAC-sanctioned transactions that were absent from F2Pool blocks are likely to have been intentionally filtered. This raises the question of why F2Pool, originating from Asia, is the first mining pool to adopt transaction filtering based on US OFAC sanctions.

The Bitcoin network functions without disruption and the actions of a single pool filtering transactions do not jeopardize its overarching censorship resistance.

However, it is important to note that F2Pool, being the third-largest Bitcoin mining pool and accounting for 13.7% of all mined blocks in the past year, means that approximately one in seven BTC blocks could potentially be mined under a censorship scenario if F2Pool actively initiates the filtering of sanctioned transactions.

F2Pool to Disable Transaction Filtering

F2Pool co-founder Chun Wang announced that the Bitcoin mining pool would deactivate the “transaction filtering patch.”

Wang stated in the post that the filter would stay inactive “until the community reaches a more comprehensive consensus on this topic.”

This revelation confirms F2Pool’s deliberate censorship of transactions sanctioned by OFAC, prompting concerns about the possibility of a recurrence in the future.