BNB Chain’s quantum upgrade halves throughput

BNB Chain tested quantum-resistant cryptography, replacing ECDSA and BLS12-381 with ML-DSA-44 and pqSTARK. The upgrade increased transaction sizes and reduced throughput by up to 50%.

BNB Chain has released reports and conducted tests on migrating its blockchain network to post-quantum cryptography, preparing for potential threats from quantum computers expected in the next 10 to 20 years. This migration would replace current cryptographic schemes—ECDSA for transaction signatures and BLS12-381 for validator consensus—with quantum-resistant alternatives: ML-DSA-44 (Dilithium2) and pqSTARK. ML-DSA-44 was chosen as it is the only NIST-standardized digital signature algorithm as of August 2024, offering efficient, smaller, and faster-verifying signatures. Testing showed the migration is technically feasible but comes with significant trade-offs. Transaction sizes increased from 110 bytes to about 2,500 bytes, block sizes grew from 110 KB to 2 MB, and network throughput dropped by 40% to 50%. Despite these challenges, BNB Chain positions itself as a pioneer in quantum-resistant blockchain security, stressing the importance of long-term preparation even though quantum threats are not yet imminent.