|Sergei Skorobogatov (BusinessInsider)|
In March it was revealed that the "FBI paid under $1 million to unlock San Bernardino iPhone". (An earlier estimate had been $1.3 million.) It now looks like the FBI overpaid. Cambridge University professor Sergei Skorobogatov performed the feat using equipment costing less than $100 [bold added]:
NAND mirroring makes a copy of a phone’s memory in its undisturbed state. Using an iPhone of his own, Dr Skorobogatov was able repeatedly to overwrite its memory with the copy he had made before he began his guesses. This caused the instrument to forget that he had made any guesses at all, avoiding any temporary lockouts and ensuring that the data would never be wiped clean. That, in turn, permitted him to brute-force the PIN six guesses at a time, resetting the phone to its original condition between each batch of guesses.Dr. Skorobogatov first came to popular attention in 2012 when he claimed that a "backdoor" had been built into U.S. military systems' computer chips made in China. These claims were denied by the defense industry. His work, including the iPhone demonstration noted above, since that episode has only enhanced his credibility, while U.S. government systems have proved to be wildly insecure.
On the other hand, why should we believe a Russian-surnamed English guy over the American government?