Bitcoin's BIP-54 proposal aims to fix a critical vulnerability known as the "attack block" issue. Maliciously crafted transactions could require nodes to spend extremely long times to verify. This problem was first discovered in 2013, exploiting the quadratic scaling characteristic of signature hash (sighash) operations in pre-(SegWit) inputs, potentially causing severe network delays or denial-of-service attacks. The soft fork solution proposed in this proposal sets a new consensus limit on the total number of CHECKSIG and CHECKMULTISIG operations per transaction in non-segregated witness inputs at 2500, thereby reducing potential verification time from several minutes to a fraction of a second, and mitigating a key bottleneck in network scalability.