$BNB Chain has tested a post-quantum cryptography upgrade for BSC, but the trial showed a clear cost: larger data loads and lower throughput.
$BNB Chain released its BSC Post-Quantum Cryptography Migration Report on May 14. The report said BSC tested post-quantum transaction signatures with ML-DSA-44 and used pqSTARK for consensus vote aggregation.
The report said the migration can work with current BSC systems. It remains compatible with existing addresses, RPCs, SDKs, wallets, and transaction flows. That means users and builders would not need to change basic account formats if the design moves into production.
$BNB Chain said, “Post-quantum readiness is achievable on BSC today,” but added that data growth and network limits remain the main trade-offs. The team also said quantum computers are “not yet at a stage” where they can break current production cryptography in real-world systems.
BSC TPS drops as signature size jumps
The main problem came from data size. $BNB Chain said transaction signatures increased from 65 bytes to 2,420 bytes after moving from ECDSA to ML-DSA-44. The full transaction size rose from 110 bytes to about 2.5 KB.
That added load cut performance in testing. The report said block size grew to about 2 MB, while throughput dropped by about 40% to 50% in tests. In cross-region conditions, TPS fell by about 40%, showing that network propagation becomes harder when blocks carry more data.
The report said finality stayed at two slots in median cases. The wider gap in slower cases came from larger blocks moving across regions, not from a failure in the consensus design.
pqSTARK aggregation keeps validator load manageable
$BNB Chain said consensus vote aggregation performed better than the transaction layer. pqSTARK aggregation delivered about 43:1 compression, helping keep validator overhead manageable during the test.
The upgrade did not cover every part of BSC’s cryptographic system. The report said peer-to-peer handshakes and KZG commitments remain outside the current migration. P2P migration would require ML-KEM, while KZG replacement would need wider Ethereum ecosystem coordination.
The test shows that BSC can move toward quantum-resistant security, but not without scaling work. $BNB Chain said network and>$BNB Chain speed roadmap faces new trade-off
The post-quantum test adds a new layer to $BNB Chain’s wider performance roadmap. Related reports noted that $BNB Chain has been targeting sub-150 millisecond finality and more than 20,000 TPS for complex transactions by 2026.
That speed goal now has to fit with quantum-resistant security work. The latest test shows BSC can adopt ML-DSA-44 and pqSTARK, but larger signatures could make high-throughput targets harder without better data handling and network scaling.
