BNB Chain developers and researchers released the “BSC Post-Quantum Cryptography Migration Report” on May 14, 2026, revealing that while new security measures can successfully defend the network against future quantum computing threats, they currently cause a 40% to 50% decrease in transaction throughput. News of the testing results began circulating through industry reports on May 18 and May 19, 2026, highlighting the technical trade-offs required for “future-proofing” the blockchain.
The migration testing focused on transaction signatures and consensus layers to counter risks posed by Shor’s algorithm, which could potentially break current elliptic curve cryptography. Although a cryptographically relevant quantum computer is estimated to be 10 to 20 years away, the proactive test on BNB Smart Chain (BSC) replaced the standard ECDSA signature algorithm with ML-DSA-44. This shift ensures compatibility with existing wallet addresses and RPCs but introduces significant data overhead.
The performance hit was most evident in native transfer speeds, which dropped from 4,973 to 2,997 transactions per second (TPS). Researchers found that the primary bottleneck is not the consensus protocol itself but the increased time required to propagate much larger data packets across the network. These findings emerge as VanEck and Grayscale move toward spot BNB ETF launches, emphasizing the importance of long-term network stability.
Significant increases in transaction and block data sizes
The migration to quantum-safe standards caused individual transaction signatures to balloon from 65 bytes to 2,420 bytes, representing a nearly 37-fold increase. Public key sizes also grew substantially, moving from 64 bytes to 1,312 bytes. This data expansion means a single transaction now occupies approximately 2.5 KB of space, compared to the previous average of 110 bytes.
As individual transactions became “heavier,” the overall block size surged during high-traffic testing. In scenarios involving 2,000 TPS, block sizes increased from 130 KB to roughly 2 MB, a 15-fold expansion. The report noted that quantum-resistant blocks are about 18 times heavier than their predecessors, which complicates the rapid sharing of data between global nodes.
Consensus layer efficiency and pqSTARK implementation
To manage the consensus layer, BNB Chain switched from BLS12-381 to the pqSTARK aggregation scheme. This specific move proved highly effective, achieving a signature compression ratio of approximately 43:1. This efficiency kept the additional burden on validators manageable, even as the lower levels of the network struggled with data propagation issues.
Despite the compression at the consensus level, cross-region finality suffered. The time required for P99 finality—the point at which a transaction is considered irreversible—degraded from 2 slots to 11 slots in the test environment. However, the median finality remained at two slots, suggesting that while peak delays increased, the average user experience remained somewhat stable during the simulation.
Addressing network bandwidth and scalability barriers
BNB Chain selected the ML-DSA-44 variant because it provides Level 2 security, which is equivalent to AES-128. Developers argued that higher security tiers would add disproportionate data size and slower verification times without providing a meaningful benefit given the current timeline of quantum threats. This decision was a strategic attempt to balance security needs with the network’s high-speed targets.
Existing challenges remain before a full rollout can occur. The current upgrade did not cover peer-to-peer (P2P) handshakes, which still require ML-KEM, nor did it address KZG commitments. These elements will likely require coordination with the broader industry, much like how Ethereum network outlook assessments often hinge on ecosystem-wide technical shifts.
BNB Chain had previously aimed for more than 20,000 TPS for complex transactions by 2026. The test results indicate that achieving “quantum-resistant” status will require significant improvements in network bandwidth and data scalability. Developers concluded that they must resolve the 40% slowdown and propagation issues before the quantum defense system can be safely enabled on the live mainnet.
