Introducing Hourglass

In the discussion regarding the strategic actions a quantum computing (QC) capable entity might undertake within the realm of cryptocurrency, particularly Bitcoin, an insightful perspective was offered. The essence of the argument revolves around the optimal utilization of Unspent Transaction Outputs (UTXOs) by such an entity to maximize its gains in mining and transaction inclusion within the blockchain.

The logic presented suggests that for an entity equipped with quantum computing capabilities, it would be advantageous to publicly broadcast its transactions. This approach contrasts with keeping transactions private, as public broadcasting allows the entity the potential to have its transactions included in blocks mined by others, not just those it mines itself. This strategy is rooted in the understanding that if the entity solely relies on its own mining efforts without broadcasting, it could only claim one UTXO per block mined, which is contingent on its hash rate share in the network.

Furthermore, the strategy of utilizing different UTXOs for public broadcasting versus those used for self-mining was highlighted. This diversification allows the QC entity to maintain momentum in mining efforts, even if another miner successfully includes one of its broadcasted UTXOs in a block. Should they use the same UTXO for both broadcasting and self-mining, the entity would be compelled to rapidly sign a new UTXO for inclusion in its own mined block, thus complicating its operations. Alternatively, maintaining a pool of targeted UTXOs from which it can sequentially draw offers a streamlined approach for continuous mining activity and block generation.

This nuanced strategy underscores the tactical considerations a quantum computing capable entity must evaluate to effectively participate in and potentially exploit the cryptocurrency ecosystem, specifically through the lens of bitcoin mining and transaction management.