## Ouch . . . so close

Posted by Michael Dickens on June 9, 2009

“The flash drive is encrypted using a 512-bit AES cipher. Right now, the computer is trying every possible key against the encrypted data.”

“How long will that take?”

“Could be hours, could be days.”

They clearly did some research, since they got most of the terminology correct. But there are two large errors.

1. AES doesn’t come in 512 bits. It only comes in 128, 192 and 256 bits. So why say it’s 512 bits? If they knew about AES, they probably knew AES’ key size, too. Is 512 just more impressive than 256?

2. Given a specialized computer designed to break AES as fast as possible, the break would take about a billion universe-lengths with a 128-bit key. With a 512-bit key, it would take about 10^400 universe-lengths. So no, not hours or days. Try *more time than can possibly be comprehended by the feeble human mind.*

Just to further the inconsistency, you will see at 3:10 that the computer is searching through a database of people. It’s doing about ten per second. That seems kind of slow, considering that they have a computer that can do roughly a BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION BILLION encryptions per second.

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