In March, just before he began killing people in a terrorist attack in London, Khalid Masood sent a WhatsApp message. A top U.K. official, Home Secretary Amber Rudd, infuriated by the government investigators’ inability to see the contents, called the app’s end-to-end encryption “completely unacceptable.”
Rudd’s reaction signaled the opening of new hostilities in the ongoing conflict between governments and technology companies over privacy and security. In the U.S., the fight has quieted a bit since Apple Inc. and the FBI faced off last year over access to encrypted data related to the San Bernardino shooting in California. But internationally, governments from the U.K. to Australia are seeking broader powers to get around encryption and other security measures in the name of public safety and law enforcement.