Scaling Noncustodial Mining Payouts with CTV

Central to the conversation is the use of Consensus-enforced Transaction Order (CTV) as a potential solution to existing limitations imposed by hardware manufacturers and the structure of blockchain transactions.

One significant problem highlighted is the restriction placed by Antminer firmware on the size of the coinbase transaction, which severely limits the number of outputs a coinbase transaction can have. This limitation hampers the ability of pools to provide non-custodial fanout transactions, forcing them to adopt workarounds that are not always efficient or feasible. The discussion brings to attention how Ocean, unlike most other mining pools, strives to offer non-custodial payouts but is constrained by these firmware limitations.

The proposed solution involves leveraging CTV to enable a single tiny consensus-enforced commitment in the coinbase transaction that can lead to a fanout transaction of arbitrary size. This approach would essentially bypass the restrictions set by ASIC firmware, allowing for any size of non-custodial mining payouts down to the dust limit while maximizing fee revenue for each block mined. However, it's noted that this method requires users to get additional transactions mined to claim their rewards and necessitates making the unroll transaction data available.

In exploring the possibilities opened up by CTV, various designs were experimented with, including a straightforward upgrade to Ocean's coinbase fanouts for better ergonomics and usability, as well as nested CTV transactions that could potentially reduce on-chain fees through coordinated action among output owners. Despite the promise shown by these designs, they come with coordination challenges and reintroduce the need for solutions to data availability issues.

Criticism of changing Bitcoin instead of ASIC firmware to overcome these hurdles was addressed by pointing out the historical difficulty of altering hardware or firmware compared to amending Bitcoin's protocols. The discussion underscores the need for innovative approaches to scale non-custodial mining payouts beyond current limitations and enhance the trust model within Bitcoin mining operations.