Apple says it won't sue FBI to find out how San Bernardino iPhone 5c was hacked

Comments on the case were given on background, without names, by Apple attorneys in a conference call with members of the media. Officials apparently said they are confident that the method used by the FBI will not be a security concern for most users, according to ZDNet.

Apple's attorneys said they did not know what method the FBI used to crack the iPhone 5c at the center of the San Bernardino terror investigation, but said that normal product development would eventually address whatever exploit was used.

FBI director James Comey revealed on Thursday that the hack used won't unlock anything newer than the iPhone 5c. Beginning with the iPhone 5s and Touch ID, Apple began implementing a secure hardware enclave that makes it much more difficult to crack into a passcode-locked iOS device.

"This doesn't work on 6S, doesn't work on a 5S, and so we have a tool that works on a narrow slice of phones," Comey said.

Comey was also noncommittal as to whether the FBI would tell Apple about the method it used, but he expressed reluctance to lose what little access the bureau does have to locked iPhones.

"We tell Apple, then they're going to fix it, then we're back where we started from," he said. "We may end up there, we just haven't decided yet."

Since the FBI revealed its success late last month, most speculation regarding their method has centered around the so-called "IP Box" that first appeared last spring. That tool — which retails for less than $300 — latches onto a susceptible iPhone's power circuitry and enters PINs over USB.

When a wrong guess is detected, the tool aggressively cuts power to the iPhone's logic board before the guess is recorded, defeating the 10-try limit.

Apple is believed to have patched this hole in older iPhones with iOS 8.1.1; as the iPhone 5c in question is thought to be running iOS 9, the FBI has either chosen a different method or has purchased the device from a company that has discovered an as-yet unreported flaw in later software.

Beginning with the iPhone 5S, PIN guesses are managed in the hardware Secure Enclave, rendering such an attack useless.

Apple's decision not to sue the FBI, and the FBI's decision to drop its complaint against Apple in the San Bernardino case suggest the issue is dying down between both sides —  for now. But the encryption debate remains contentious between Apple the FBI's parent agency, the U.S. Department of Justice, which revealed on Friday it plans to continue pushing to force Apple to unlock an iPhone 5s at the center of a Brooklyn drug trafficking case.