22 June 2012

"At Close Range"

By Curtis C. Chen

The guard held up the unlabeled cassette tape and looked at Lisa. "What's this?"

She'd been practicing her answer in front of the bathroom mirror, but her heart rate still accelerated as she stammered, "Just some music. You know, background music for while I'm working. It gets kind of lonely in that big empty computer room all by myself."

"Uh-huh." The guard narrowed his eyes. "What kind of music?"

"It's the new Madonna album," Lisa said. "I have the LP at home, but, you know, it's not really convenient to carry a record back and forth."

The guard looked to be in his fifties, and Lisa wondered if that stony stare had won him many poker games. She felt her palms sweating as she waited, not wanting to say too much.

After a moment, the guard put the tape down. He fished around inside her purse, found her Walkman, and set it on the counter next to the tape.

"Nice lady like you ought not to be listening to music like that," he said, not looking at Lisa.

"Well, I think she's a real inspiration, but to each his own. What kind of music do you like?"

"I like Johnny Cash."

"Right," Lisa said. "Because shooting a man in Reno just to watch him die is so much more wholesome than, you know, sex."

The guard gave her that look again, then loaded everything back into her purse and slid it across the counter.

"You have a nice evening, Professor," he said.

"Do my best," Lisa muttered, grabbing her purse and hustling out of the building.


The PLAY button on the tape deck popped up with a clank. Lisa stopped writing in her notebook and turned back to the computer. She entered a command to verify that the data from the tape had transferred successfully over to the hard drive:

X:\>dir /w

 Volume in drive X is BIGMAC
 Volume Serial Number is 1234-5678

 Directory of X:\

PING.002       Q.002
RAVEN.003      ROT13.003
TIME.005       UNROLLED.005

              12 File(s)     34,567,890 bytes
              0 Dir(s)       12,345,678 bytes free

Oh no! Where is it? Lisa's heart skipped a beat before she remembered that she'd encrypted the contents of the tape. That's right...

She had been confident that the exit inspection guard at the Army base wouldn't know that audio cassettes could also be used to store digital computer data, but a little paranoia never hurt when it came to security measures—especially when you were smuggling classified information out of DARPA. Lisa couldn't sleep at night unless she made off-site backups of her code, and it was easier to circumvent the restrictions placed on her government work than to argue with the military.

The problem was, Lisa couldn't remember the passphrase she'd chosen. She was pretty sure it was a three-word phrase, and she knew she'd coded it into the fake filenames based on helical scan, the way data was actually written onto tape—maybe those numbers in the file extensions were a clue? She wouldn't be able to recover her project until she figured it out...

Solve the puzzle and e-mail profgoto@snout.org to get your name on the leaderboard! (Hints also available by e-mail.)


Image: memorex cassette tape by Jonathan Blundell, September, 2010