BNB Chain Ditches Old Crypto for Quantum-Resistant Upgrade

BNB Chain has successfully tested its post-quantum cryptography upgrade on the Binance Smart Chain (BSC), but at the cost of a significant throughput drop. The test showed that the new system can withstand quantum attacks, but it comes with a price: transaction sizes ballooned 37 times in size and throughput fell by roughly 40%.

The team tested two replacements for the older cryptographic systems: ML-DSA-44, a lattice-based signature scheme standardized under FIPS 204 in 2024, and pqSTARK aggregation for validator consensus votes. The test results showed that block sizes climbed from around 130 KB to nearly 2 MB at equivalent load, while median finality latency held steady at two slots across all test scenarios.

The biggest performance hit came from cross-region data transfer, not signature verification itself, developers noted in the report. However, the pqSTARK proof system delivered a striking result: six validator signatures totaling 14.5 KB compressed into a single proof of about 340 bytes, a 43-to-1 reduction that kept consensus efficient even under heavier cryptographic loads.

BNB Chain framed the work as a proof of concept rather than a production rollout, stating that throughput constraints at the network and data layer remain the central obstacle. The report also flagged P2P handshakes and KZG commitments as outside its current scope, requiring broader coordination with the Ethereum ecosystem.