BNB Chain post-quantum cryptography test lowered BSC throughput by about 40% on May 19, 2026

BNB Chain said a proof-of-concept upgrade to post-quantum cryptography kept BSC operating but cut throughput by roughly 40% on May 19, 2026. Cross-region performance fell from about 4,973 transactions per second to around 2,997, mainly due to much larger transaction payloads and block sizes rather than signature verification delays.