Apple is letting developers peer into the core of its mobile operating system for the first time - a move that could have major implications for security, BBC reports.
Last week the tech firm released a preview version of iOS 10.
Its kernel - the central component that controls how software is processed by a device's hardware - was unencrypted.
The move should make it easier for researchers to flag flaws that could otherwise be exploited by hackers.
However, the BBC understands that was not Apple's motivation for making the change.
Even so, experts say it could make it harder for organisations to keep secret techniques they have used to overcome privacy measures on iPhones and iPads.
In a recent high-profile case, the FBI refused to share an exploit it had used to to crack an iPhone used by a gunman who had killed several people in San Bernardino, California.
"In general, transparency is good for security," commented Dr Steven Murdoch from University College London.
"Well-resourced attackers like government intelligence agencies have always been able to find vulnerabilities.