FBI refuses to reveal security flaw it used to access of San Bernardino gunman's iPhone 5C

The FBI yesterday confirmed it would not reveal to Apple the security flaw it leveraged to break into the iPhone 5C of San Bernardino gunman Syed Farook, saying it did not buy the rights to the technical details of the hacking tool.

According to commentators, the declaration would add to the curiosity about the FBI's last-minute abandonment of its high-stakes court battle with Apple, the most valuable company in the US.

The day before two were to clash in court over whether the government could force Apple to unlock the phone, the government resiled, saying thanks to a special hacking method, it no longer needed Apple's help.

The FBI had offered few details about the hacking tool. According to the agency, the method came from outside the government and worked only on an iPhone 5C (See: FBI paid hackers for key to San Bernardino iPhone).

Meanwhile, the FBI is expected to soon write to the White House explaining why the agency could not share the unlocking mechanism with other government agencies, Apple or other third parties, according to sources, who asked to remain anonymous, Reuters reported.

According to several US government sources, the FBI contractor that unlocked the shooter's phone was a foreign entity and did not give US authorities details of the mechanism. Without that, the FBI could not share details even if it wanted to, sources said.

According a Reuters report dated 13 April, the unnamed contractor had sole ownership of the method it used, making it unlikely that the government could share it.

A day later, the FBI warned Apple of a separate flaw in its iPhone and Mac software, Apple told Reuters on.

According to the company, it was the first instance of the government alerting Apple to a vulnerability under a White House interagency procedure, known as the Vulnerabilities Equities Process, for reviewing technology security flaws and deciding which ones should be made public.