B6-2 Door Locks (Patreon)

Rearranged and rewritten from the first draft.

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When Tori and Sese marched into engineering, Runo’oa froze, the expression on his ears tragic. Activity around him continued unabated, the other engineers paying no notice to the two visitors, but the middle-aged geroo stood stock-still in the center of all that commotion like an actor who had forgotten his lines.

“What are you doing here?” he hissed at Tori when she stepped close. “This is my workplace!”

“Yeah, so?” asked Sese. “Got something you’re hiding from them?”

“No! I don’t want them to see me talking to you!” He looked so upset, his ears were trembling.

“It’s no big deal,” Tori reassured him. “Everybody is being interviewed by security over the next few days. You’re no different.”

He crossed his arms in defiance. Didn’t offer to take them somewhere private, didn’t offer Tori a seat. “What do you want?”

“I’ve got a few questions—”

“I already answered your questions,” he growled over her.

“Yeah,” said Sese, leaning closer, “and now she has some more. Get used to it.”

He covered his eyes for a moment and then glared at Tori once more. “What?”

“How hard would it be for someone to break into an apartment without a trace?” she asked. “Could they disassemble the lock—”

“No, they can’t,” he said, sounding aggravated.

“I mean like in the action videos where the hero opens one up,” she said, “and touches some wires together—”

He was shaking his head.

“Why not?” asked Sese.

Runo’oa growled, but softly this time, under his breath. “The door locks have two parts. There’s a locking mechanism that holds the bolt closed—it’s the part you hear click when you enter the code on your strand. The other part is the wireless interface—it’s the part that communicates with your strand.”

“You can’t take them apart?”

“You can, but the locking mechanism is on the inside of the apartment,” he explained. “Before you could disassemble it and touch wires together, you’d have to already be in. At that point, you could just turn the knob.”

“Aw, you’re ruining videos for me,” Sese groaned. “What about the other bit? It’s on the outside?”

“The wireless interface. Yes, it’s one outside,” he said, nodding.

“So, you could—”

“But disassembling it won’t help you get inside,” he said. “Its job is to encrypt and decrypt radio messages, to transfer your device identifier to the locking mechanism.”

Tori shook her head. “Device identifier?”

“It’s just a number, a really big number with hundreds of digits,” he groaned. “Every strand has one and they’re all different. The locking mechanism keeps a list in memory of all the device identifiers it will open for. And taking the wireless interface apart isn’t going to make it any easier to guess one of the device identifiers on the list. Shorting wires together is just going to break it, not communicate a really big number over to the locking mechanism.”

“I guess that makes sense,” sighed the big officer. “It wouldn’t be much of a security system if you could bypass it easily.”

“Okay,” said Tori, deep in thought. “So, you walk up to a door, you type in your code, it transmits your big number to the wireless bit, which passes the number to the lock part, and if the number is in a database, it unlocks, right?”

“Right,” he grunted, then glaring over Sese and her screwdriver, he repeated, “Taking one apart won’t get you inside.”

“Hey!” cried Sese, wagging the tool at the engineer. She started to say more, but Tori already had another question.

“Okay, I know I’m going to regret asking this,” she said, “but why would that identifier number need to be so big? There’s only ten thousand geroo on board. Why not identify our strands with one, two, three, and so on, up to ten thousand?”

Runo’oa sighed and gestured for the two to follow before leading the two outside the hustle and commotion of the engine room. In the quieter corridor, he explained, “The device identifier is a huge number to make it hard to hack.”

Tori’s eyes opened wider. “So, it could be hacked.”

He frowned for a moment. “Let’s say you wanted to get into my apartment without stealing my strand. What you’d need is the device identifier number that’s hidden away in its memory. And then you’d reprogram your own strand with my device identifier.”

She nodded. “So, if my strand had your number, then I could unlock it. When I typed in my code, it would send your number to the lock, and since the number is in its memory, it would open.”

“Exactly,” he said.

“So, how do I get the code out of your strand?”

Runo’oa shrugged. “I don’t know! I’m not a hacker. But the point is that you can’t just use the numbers one through ten thousand. If you did, the hacker wouldn’t need to steal the number from my strand. He could just guess it.”

Officer Sese scowled. “And if he guessed wrong?”

“He could just guess again,” said the engineer. “Computers are really fast. It could try one, try the next one, and so on until it got it right. I don’t know how long it would take to get through ten thousand numbers, but I doubt it would be very long at all.”

“But if it was a really big number,” said Tori, “a number with hundreds of digits…”

“Hundreds of digits means billions of billions of billions of combinations,” he said. “Even a computer trying one after another super-fast would never accidentally stumble across the right one. It would take the rest of eternity—statistically speaking.”

Tori frowned. “So, you’d need to steal someone’s strand.”

“Which would be reported,” said Sese.

“Or steal someone’s number,” repeated Tori.

“Which would require hacking,” sighed Sese.

“Are you satisfied?” the engineer whined. “Can I go?”

Tori nodded. “Yeah, okay. Thanks for your help.”

“Like I had a damn choice,” he muttered under his breath before scuttling back to work.

Sese stared at his back. “I hate him.”

“I know, but that was useful information,” Tori sighed as she headed down the corridor toward the center of the ship. “Fairly reassuring too. I’m glad it would take more than a screwdriver to break into my apartment.”

“But it leaves us where we started,” said Sese. “A teen small enough to sneak through an air vent, Captain Gutassi, Chief Tipohee, or a hacker.”

“Unless you know a hacker,” Tori said, “I guess that means we talk to Computer Chief Nija next.”

The big geroo scowled.

“Don’t like her?” asked Tori.

“I’ve only met her twice,” Sese said. “You were there when someone accused her cub of filming Boots. The other time was a few years back, when she stomped into security, pissed about something or other—some sort of overlap between ship security and computer security. I guess both she and Tipohee felt it was their territory.”

“Oh yeah?”

Sese nodded. “Best I could tell, they were trying to solve it by seeing who could yell the loudest.”

“Lovely,” yarped Tori. “So, who won?”

“Beats me,” Sese said with a shrug. “I excused myself and left them to it. I’ve got better things to do than listen to screaming.”

Tori nodded. “Good move. I see now why the chief wanted you to come along when he interviewed Asui.”

Sese grinned and gave Tori a wink. “I had his back, and I’ve got yours now.”

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Reviewer's link: https://docs.google.com/document/d/1HVl5TyWrrBiTykB_MD_v4txbzDEl2t-UDnbwiRbnJ0M/edit?usp=sharing

Thoughts?