Great Consensus Cleanup Revival

By leveraging the OP_RETURN operation within the coinbase transaction, miners can effectively increase the nonce space, allowing for a more flexible and efficient mining process.

This method involves appending a zero-value output with a specific structure to the coinbase transaction. The structure includes the OP_RETURN operation followed by a push operation that introduces a nonce composed of four bytes plus an optional extension to ensure alignment. The size of this extension is dynamically calculated based on the total size of the coinbase transaction (excluding the witness data), ensuring that the end of the OP_RETURN data aligns optimally for hashing purposes. The proposed range for additional coinbase data required to achieve this alignment varies from 14 to 30 bytes, offering a practical solution for miners to update the nonce without significantly increasing the transaction size.

Furthermore, the technique presents an alternative to using the nLockTime field as a nonce, which itself can necessitate up to 12 bytes of padding for proper alignment. The advantage of utilizing the OP_RETURN method lies in its minimal overhead, especially when miners are already employing OP_RETURN outputs for extranonce work. The additional space required for alignment in this context is negligible, ranging from zero to four bytes.

By expanding the nonce space through this mechanism—coupled with the existing 32-byte nNonce, 16-byte flexibility afforded by BIP 320, and the potential for rolling the nTime field—miners have access to a significantly enhanced nonce capacity. This capacity is quantified as supporting up to 1200 zettahash per second, or approximately 1000 times the current total hashrate of the Bitcoin network. This vast increase underscores the potential of the proposed method to accommodate future growth in hashing power while maintaining the integrity and functionality of the mining process.

In essence, this approach not only offers a technical solution to the constraints on nonce space within Bitcoin's mining protocol but also reflects the ongoing innovation and adaptability within the community to address operational challenges. By providing detailed calculations and considerations, the discussion contributes valuable insights into the optimization of Bitcoin mining operations, highlighting the collaborative effort to enhance the cryptocurrency's underlying technology.