A sharp drop in the Bitcoin blockchain's hashrate, down 10% on Sunday, during this week’s U.S. winter storm, is offering a real-time stress test of a concern long flagged by researchers: mining centralization has turned local infrastructure failures into system-level risks. Hashrate is the amount of computing power available to process transactions required to keep the Bitcoin blockchain running at any given moment. When it drops sharply, the network has less room to process transactions, increasing the ri ...