№ 001Bitcoin

Bitcoin's Quadratic Sighash Bug, Explained

Before SegWit, a single crafted transaction could stall nodes for minutes. The mechanism, the real attack surface, and what BIP143 actually changed.

Daniel Brooks7 min read / 28.07.2026

№ 002Bitcoin

How SegWit Changed Bitcoin Transaction ID Calculation

SegWit didn't just shrink fees. It fixed a subtle flaw in how Bitcoin transaction IDs are built. Here's the exact mechanism, explained clearly.

Daniel Brooks6 min read / 13.06.2026