On Proof-of-Work Integrity: From KHeavyHash to SwiftHeavy

1. The Failure of KHeavyHash In late 2023, Toni Lukkaroinen published an analysis of Kaspa’s KHeavyHash:KHeavyHash is broken. The core issue is simple. KHeavyHash inserts a matrix multiplication step, but discards entropy by applying a fixed right sh...