FBI Director James Comey told reporters that "NAND mirroring" will not be used to get into the work iPhone of dead terrorist Syed Farook, saying "It doesn't work." Mr. Comey made the comments during an unrelated press conference announcing indictments on seven Iranian nationals charged with hacking banks and a U.S. dam.
Reporters used the opportunity to ask questions about the ongoing fight with Apple over Syed Farook's iPhone, including speculation that the method most likely to be used by an unnamed third party (that may actually be named Cellebrite) is NAND mirroring. This technique was openly proposed by the ACLU on March 7th and tossed around by other observers even earlier.
NAND mirroring is a technique for copying the data on an iPhone by pulling it apart and mirroring the information contained on individual chips within the device. Forensic engineers could then test each copy 10 times—even if iOS wipes the data after the tenth try, those engineers can just move to another copy.
With only 10,000 possible four-digit password options, it's a labor-intensive—yet doable—way to brute force a device. It also has the benefit of not requiring Apple to weaken iOS security by creating a backdoor. The FBI has been criticized by the ALCU, some pundits, some security experts, and even members of the U.S. Congress for not using this method already.
When the FBI announced that a third party had stepped forward with a method for accessing the device, many assumed it would be NAND mirroring, and reporters asked Director Comey if that was the case.
"I've heard that a lot," Mr. Comey said with a shake of his head, according to ComputerWorld. "It doesn't work. We've had lots of people come forward with lots of ideas, and now we have one."
The director did not specify what method had been proposed or why the FBI believed it would work.
Mr. Comey also said that the FBI and the U.S. Department of Justice would continue to press for backdoor access into encrypted devices and communications, despite the intelligence community, tech firms, and security experts saying it's a bad idea.
"Our goal all along is to facilitate an adult conversation about a serious conflict between two things we all care about," Mr. Comey said. "That is our goal. San Bernardino is about that investigation. Even if this particular technique makes that go away...we still have to resolve this conflict between these values we care about, and we hope there will be an adult conversation."
Let's hope that adult conversation includes a dose of reality about backdoors. With Mr. Comey insisting there can be a compromise on backdoors, that doesn't seem likely.