Biggest Post-Quantum Challenge Facing Bitcoin: BNB Chain Research

BNB Chain Research warns that the largest post-quantum challenge for blockchains like Bitcoin and BSC is not consensus vulnerability but the dramatic increase in transaction and block sizes from quantum-resistant signatures. Testing replacing ECDSA/BLS with ML-DSA-44 showed average transaction sizes rising from ~110 bytes to ~2.5 KB and blocks from ~130 KB to nearly 2 MB, which reduced throughput by ~40–50% due to longer propagation and higher finality delays. pqSTARK aggregation compresses validator signatures (~43x) but network bandwidth and propagation become the main bottlenecks, implying major infrastructure upgrades may be needed to retain current speed and scalability despite no immediate cryptographic break risk.