The theft of at least $6.3 billion in cryptocurrency from the world’s marquee digital-asset exchange shows that however sophisticated the fortifications, high-tech criminals are still finding a way in.

Hackers absconded with the biggest single haul in the history of cyber attacks, forcing the exchange, Binance, and its partners to freeze billions of dollars of assets, and shaking confidence in crypto-market infrastructure. While Binance promised to reimburse lost funds from customers, the heist was another blow to the security framework of an industry trying desperately to win the trust of institutional Wall Street.

“This is the largest cyber theft on record, not just the largest in crypto,” said Aneirin Flynn, chief…