Recent advances push Big Tech closer to the Q-Day danger zone

Sometime around 2010, sophisticated malware known as Flame hijacked the mechanism that Microsoft used to distribute updates to millions of Windows computers around the world. The malware—reportedly jointly developed by the US and Israel—pushed a malicious update throughout an infected network belonging to the Iranian government.

The lynchpin of the "collision" attack was an exploit of MD5, a cryptographic hash function Microsoft was using to authenticate digital certificates. By minting...