The tool purchased from a private party and used to access an iPhone belonging to one of the San Bernardino shooters only works on a "narrow slice" of phones, FBI Director James Comey said Wednesday night.
Speaking to a group at Kenyon College in Gambier, Ohio, Comey said the government is considering whether to share with Apple how officials were able to access an iPhone 5c used by Syed Farook.
"We're having discussions within the government about, 'OK, so should we tell Apple what the flaw is that was found?'" he said. "That is an interesting conversation because if we tell Apple, then they're going to fix it and we're back where we started from."
Federal officials announced last month they successfully cracked into an iPhone used by Farook and no longer needed Apple's help in unlocking the device. The Department of Justice and Comey have said all along that the solution they sought in breaking into Farook's phone would only work on this one phone -- the 5c running iOS 9.
Comey did not reveal the third party that helped the FBI crack into the phone, but said he knows "a fair amount about them" and is confident they'll keep the method used to access the phone private.
"The FBI is very good at keeping secrets and the people we bought this from -- I know a fair amount about them and I have a high degree of confidence that they are very good at protecting it and their motivations align with us," he said.
Apple has been staunch in its position that creating a backdoor for government officials would undermine the security of millions of users. However, Comey said the "slippery slope" argument is a "fallacy."
"The controversy over the Apple case, the challenge of encryption more broadly, has been chock full of slippery slope arguments and absolutist arguments," he said. "Every time you hear someone making a slippery slope argument, an alarm should go off in your head."
"The notion that privacy should be absolute or the government should keep their hands off our phones, to me just makes no sense given our history and our values," he said.
After the Department of Justice dropped its case against Apple last month, the company issued a statement saying legal action should never have been brought.
"From the beginning, we objected to the FBI's demand that Apple build a backdoor into the iPhone because we believed it was wrong and would set a dangerous precedent. As a result of the government's dismissal, neither of these occurred," Apple said. "We will continue to help law enforcement with their investigations, as we have done all along, and we will continue to increase the security of our products as the threats and attacks on our data become more frequent and more sophisticated."
"This case raised issues which deserve a national conversation about our civil liberties, and our collective security and privacy. Apple remains committed to participating in that discussion," the company added.