Apple launched the challenge at the annual Black Hat security conference in Las Vegas.

In order to remove exploitable vulnerabilities from its mobile operating system, Apple Inc has announced a bounty of up to $1 million to cyber security researchers who detect flaws in iPhones.

This is the largest ever reward Apple has offered to bounty hunters as a defense against wannabe hackers.

Previously Apple had offered rewards to only a select hand-picked group of cyber security researchers for finding flaws in its phones and cloud systems.

On Thursday, at the annual Black Hat security conference in Las Vegas Apple said it would open the process to all researchers.

Incidentally, the $1 million prize can be snagged only for discovering remote access exploits which don’t require any action from the phone’s user.

Brokers and Government contractors have paid as much as $2 million for the most effective hacking techniques to break into devices.

In order to make the job of finding these exploits easier, Apple is offering a modified phone that has some security measures disabled.

A number of private companies, including Israel’s NSO Group, sell hacking capabilities to governments.

“NSO Group develops technology that is licensed to intelligence and law enforcement agencies for the sole purpose of preventing and investigating terror and crime,” said NSO in a statement. “It is not a tool to target journalists for doing their job or to silence critics.”