WhatsApp has joined Apple in defying the US government’s efforts to access mobile phone users’ private messages by rolling out tough encryption protection that will prevent law-enforcement agencies from snooping on its more than one billion users.

The Facebook-owned chat app expanded its end-to-end encryption just weeks after Apple narrowly avoided a legal showdown with the FBI over access to the iPhone owned by a shooter in the San Bernardino terrorist attacks.

WhatsApp will hold no keys to users’ private communication and so could not grant agencies access even if they had a warrant. Law-enforcement agencies have warned that increasingly sophisticated encryption on digital communications could hinder their ability to track terrorists and criminals. Tech groups say weakening encryption would make it easier for cyber criminals to attack customers.

Jan Koum, WhatsApp co-founder, said protecting communication was a core value at WhatsApp. “The idea is simple: when you send a message, the only person who can read it is the person or group chat that you send that message to,” he wrote in a blog.

– (Copyright The Financial Times Limited 2016)