Optimal blockspace allocation strategy for Bitcoin’s quantum-safety upgrade transactions

Determine which Bitcoin blockspace allocation strategy is more optimal for scheduling quantum-safety upgrade transactions that migrate existing ECDSA-based UTXOs to post-quantum addresses: dedicating every k-th block entirely to upgrade transactions or allocating a fixed 1/k fraction of each block to upgrade transactions, given the specifics of real-world transaction-packing algorithms and empirical network data.

Background

The paper analyzes the downtime and throttling required to transition Bitcoin from ECDSA to post-quantum signature schemes. Because dedicating all blocks to upgrades is infeasible, the authors discuss interleaving upgrade transactions with normal activity.

They identify two natural scheduling strategies for allocating transaction bandwidth to upgrades: (1) dedicating every k-th block fully to upgrade transactions and (2) allocating a 1/k fraction of each block to upgrades. The authors explicitly state that it is an open question which of these two approaches is more optimal, noting that the answer depends on details of transaction packing and real-world data.

References

The alternative is to allocate a k'th-fraction of each block for upgrade transactions. Which of these approaches is more optimal is an open question, whose answer would depend on the particulars of the packing algorithms used, and real-world data.

— Downtime Required for Bitcoin Quantum-Safety  (2410.16965 - Pont et al., 2024) in Section 5 (Discussion), footnote to the paragraph on designating every k'th block to upgrade transactions