BNB Chain's post-quantum cryptography migration test revealed significant performance trade-offs for the BSC network. According to the BSC Post-Quantum Cryptography Migration Report released this week, the migration from ECDSA to ML-DSA-44 signatures resulted in transaction signature size increasing from 65 bytes to 2,420 bytes, while full transaction size rose from 110 bytes to approximately 2.5 KB. The performance impact was substantial, with block size growing to about 2 MB and throughput dropping by about 40% to 50% in testing conditions. Cross-region native transfer workloads specifically dropped from 4,973 TPS in non-post-quantum configurations to 2,997 TPS under the upgraded system, while mixed workloads experienced a smaller decline from 3,695 TPS to 2,406 TPS. Larger transaction sizes shifted the network bottleneck from gas limits to bandwidth and propagation latency, as reported in the migration report.
The migration test utilized ML-DSA-44 signatures and pqSTARK for consensus vote aggregation, as reported in the migration report. BNB Chain confirmed that the migration remains compatible with existing BSC systems, including current addresses, RPCs, SDKs, wallets, and transaction flows. The consensus vote aggregation performed better than the transaction layer, delivering approximately 43:1 compression and helping keep validator overhead manageable during testing. The project did not include peer-to-peer handshake encryption or KZG commitment systems, which remain under consideration for future upgrades. BSC selected ML-DSA-44 from among three standardized parameter sets, citing lower signature size and faster verification speed as the main reasons for the choice, with larger variants creating substantially more network overhead while offering limited practical benefit under current threat projections.
The test results highlighted that cross-region TPS fell by about 40% due to network propagation difficulties when blocks carry more data. As reported in the migration report, median finality remained stable at two slots, although worst-case finality increased in cross-region testing because larger blocks took longer to propagate between validators. The slowest 1% of confirmations took up to 11 slots in cross-region tests, with larger blocks taking longer to travel between regions causing significant delays. BNB Chain acknowledged that while 'post-quantum readiness is achievable on BSC today,' data growth and network limits remain the main trade-offs for the migration. The team noted that quantum computers are 'not yet at a stage' where they can break current production cryptography in real-world systems.
The post-quantum test adds complexity to BNB Chain's broader performance roadmap, which has been targeting sub-150 millisecond finality and more than 20,000 TPS for complex transactions by 2026. According to related reports, the larger signature sizes could make high-throughput targets more challenging without better data handling and network scaling solutions. BNB Chain emphasized that network and data-layer scaling remain the main barriers before production deployment of the quantum-resistant security features can proceed. The findings demonstrate that standardized post-quantum cryptography can already be integrated into blockchain infrastructure, though additional work will be needed to address scaling and networking constraints before broad production deployment. The report noted that other parts of the system still need quantum-safe upgrades, with some work requiring assistance from the wider Ethereum community.
