Here & There

by Joshua V. Scher

  He sits at a white Formica workstation in the center of his lab, across the room from his webcam.24 Two whiteboards, covered with equations, stand like hieroglyphic centurions behind him. In front of him, the lettered, leather tail of a half-unraveled scytale dangles off the edge of the desk. His left elbow rests on the table, and he uses his forearm to brace a mirror held at an angle facing the tabletop. Though it’s blocked from view by his torso, judging from the movements of his right arm, it appears he’s writing something. And he wears an eye-patch over his right eye.

  Eve bursts in with the Swiss contingency in tow.

  “Here we are at last, et voilà, here is your genius,” Eve says with a flourish.

  Reidier, startled, lets go of the mirror, which slams onto the tabletop and shatters.

  “Busy with his reflections clearly,” Eve puns. She turns away from the Swiss with a laugh and faces Reidier, flashing him a smile and winking.

  Reidier lifts the eye-patch up and stares at her a moment. He clears his throat. Eve’s eyes widen, silently asking for help. He then turns his back on them and continues with his work.

  Eve seems lost, briefly. She turns to the Swiss group and overdramatically shrugs her apologies.

  One of the suits steps forward and asks, “Monsieur Reidier, we were hoping you might show us a demonstration of our new protocol?”

  In an almost Jekyll and Hyde transformation, Reidier becomes effusive and welcoming, going on about rules of physics before he’s covered even half the distance across the lab. He brushes past Eve and ushers the UBS reps over to his whiteboard, prattling on about secure transmission, eavesdropping, and two hypothetical spies, Alice and Bob.

  Eve is left to stand by the door, watching with a bemused look on her face. Eventually, she pulls up a stool and listens to Reidier going off about how Alice and Bob both have a cipher on a pad of paper. Alice codes a message with her copy of the cipher and Bob deciphers the message with his copy. It’s completely unbreakable, Reidier says, as long as it’s a one-time pad, except that the length of the key had to be at least as long as the text, which isn’t useful beyond espionage until computers came along. “Now we could easily handle ciphers with a key that had 256 values, and breaking the code would be a hopeless task, except . . .”

  Reidier waits. He has the bankers’ undivided attention. He continues, “All systems that depend on a single secret key have an Achilles’ heel. Using the same key for encoding and decoding results in a symmetrical cipher.”

  “Hence, PKC,” pipes up the suit who originally got Reidier started.

  “Exactly,” Reidier agrees, “Public-Key Cryptography utilized two different keys, the public and the private, in what most mathematicians agree to be the most significant practical discovery of the twentieth century. It’s just . . .”

  Reidier nonchalantly trails off, and busies himself organizing a row of markers on the whiteboard tray.

  In an almost laughable choreography, every member of the Swiss contingency literally leans in toward Reidier. Eve, on the other hand, leans back in her stool, taking in the whole picture. A hint of a smile at the corners of her lips.

  “We’re not in the twentieth century anymore.” He looks up at his rapt audience. “Any and all private communication channels utilized today have a soft underbelly. A critical weakness. Every ‘secure’ communiqué relies on it, and therefore everyone can be tapped.”

  A few murmurs from the Swiss.

  “If an eavesdropper takes enough precaution, he can listen in to a communiqué without the sender or receiver knowing. Classical physics allows, at least in principle, physical properties to be gauged without disturbing them. If your cryptographic key is encoded in measurable physical properties of some object or signal, then there is nothing to stop me from passively, undetectably, tapping in to your channel, breaking your code, and listening in on all your secrets. But with QKD, Quantum-Key Distribution, with quantum cryptography, I can change all that—”

  The video cuts out there to a DARPA insignia. Presumably, it just goes on getting deeper into the non-classical physics of Reidier’s quantum cryptographical methods. It is unclear how Reidier and Eve ended their first meeting but not how they finished their first day. Not if we’re to interpret Eve Tassat’s short story, “Empêtré Le Bourg,”25 as more fact than fiction.

  Excerpt from “Empêtré Le Bourg”

  . . . She found him in le vieux bourg, in Oublié, an abandoned Créole mansion that had been converted into a bar by squatters. He had separated from the group a few hours ago and made his way here. The Germans hadn’t even noticed. They were too busy swilling Brahma Beer and comparing French cuffs. No more talk of security transactions or the fidelity of physics. Just shouting voices and wandering hands. Even so, it wasn’t as easy for her to slip away. She had to employ some misdirection with the help of three Guianese girls and a bottle of Highland Park Scotch.

  Reinier sat on the edge of a high-backed Louis XIV chair with faded, worn red velvet cushions. Naelle, the plump bartender and mama of the house, leaned her fleshy forearms on the back of his chair, watching his work. Reinier hunched over an old coffee table stained with rings of neglect and cluttered with several glasses, some pewter swizzles, a slotted silver spoon, a saucer of stacked sugar cubes, a cup of granulated sugar, a pitcher of ice water, a small bottle of gum syrup, a small bottle of liqueur d’anis, a half glass of white wine, a bottle of cognac, a matted-steel Zippo lighter, and a bottle of absinthe.

  Reinier carefully put down the pitcher of ice water and sat back. The motley pair stared at a soggy sugar cube sitting on top of the flat perforated spoon that rested on the rim of a glass of absinthe. At least a minute passed, and still the cube held together.

  “A bit more ice water,” Naelle urged with a thick Créole accent.

  “It’d be faster with tepid water,” Reinier sighed.

  “You might as well be drinking pissat d’âne ou du bouillon pointu!”26 she snapped.

  “I hardly think it’d be quite that extreme. However, your house, your rules.” He added a few more drops, and the sugar cube finally began to sink through the slots. They waited.

  She watched them from the arched threshold. She wasn’t spying, just keeping her distance so as not to disturb the bizarre tableau.

  The sugar cube was half of what it was. Reinier looked up at Naelle. She pursed her thick dark lips and nodded, her chins winking in and out of existence with each bob of her head. Reinier removed the spoon, picked up the glass, swirling the mixture in tight circles, and took a slug. He paused, clucked his tongue against the roof of his mouth a few times, and handed the drink to Naelle. She lifted her pinky and took the daintiest of sips.

  “D’ere, you see? That is the way.”

  Reinier shrugged. “It’s not bad, that’s for sure. Still, cutting it with the cognac was nice too.”

  “Un Tremblement de Terre? Pah! Thass what made Toulouse-Lautrec paint like that. How well you think you could write your calculations wearing a straitjacket?”

  Reinier laughed.

  Naelle patted his shoulder. “So then, we done with the s’periment. We see this is the only way to do it, right.”

  “We haven’t tried the caramelized sugar method,” he said, reaching for the Zippo.

  Naelle sucked her teeth loudly. “They do it in one stupid movie and all of a sudden it’s a tradition.”

  “It’s a Bohemian ritual.”

  “Bo’emian ritual. Who ever looked to Eastern Europe for culcha? They just alcoholic pyromaniacs.”

  “I have to agree with Naelle on this one, fire and alcohol never go well together,” she interrupted.

  Reinier looked up at her and squinted, trying to place where he knew her from. She laughed quietly to herself at this. Any other man from the Centre, this would have been a ploy. Not so with Reinier.

  “See, the Tremblement de Terre already kickin’ in. Mirages and hallucinations are filling up the place.” Naelle raised an eyebrow at her.

>   “Absent n’est point sans coulpe, ni présent sans excuse,”27 she offered.

  “Les absents ont toujours tort,” 28 Naelle quipped back.

  “Un peu d’absence fuit grand bien.”29

  Naelle snapped a dishtowel in the air. “That’s only true with men. S’ok. I don’t need no flattering. I know the truth. The truth is you just scared to bring your visitin’ big shots to Maison de Mama. Lose them in my Oubliette,” Naelle said over her shoulder as she walked back to the bar, swinging her large hips to punctuate her innuendo. Her laugh filled the space between them. “Pour mieux le peindre, il faut quitter Paris.30 But there’s no way to leave an oubliette.”

  She sat down across from Reinier. He took another sip of absinthe, gazing at her with puzzled eyes.

  “You lost me after ‘absent.’ I mostly only know slang and curse words. They’re all she’ll teach me.” He nodded his head toward Naelle.

  She half laughed, half exhaled. “It’s only fair. You lost me today at public-key cryptography.” She dug into her purse and pulled out a flat, gift-wrapped object. Handing it to him, she said, “A peace offering?”

  He took it from her but didn’t seem to know what to do with it. Just held it in midair, over the coffee table cluttered with absinthian concoctions.

  “You can open it,” she suggested.

  Shaking off the haze, he unwrapped the object.

  “Interesting tie clip,” she said.

  “It’s the secret of my success.”

  “Really? Because it looks like you ripped a piece out of a computer and soldered it to a paper clip.”

  “Close. A transistor from my first computer that I ever made. My Alpha chip, I guess. I like to keep my spark of ingenuity close . . .” He trailed off, having finished unwrapping her peace offering. He was left holding a hand mirror with a pink plastic frame and handle.

  “Figured it was the least I could do for breaking your concentration and your mirror today.” She smiled. “Friends?”

  He stared at the mirror, wiggling it a little in his grip. “It’s magnificent. And pink.”

  “That’s what I thought when I looked at it,” she teased.

  “I didn’t mean—”

  “To be vain?”

  “That’s not what I—”

  “Vanity is just a word ugly people invented to make themselves feel better. I wouldn’t worry about it.” She flashed a big smile.

  It wasn’t working. He still hadn’t looked at her.

  “It’s very thoughtful.” He sat back and took her in. “Elle, is it?”

  Her smile evaporated. She nodded yes.

  “Thank you, Elle. Can I buy you a drink?”

  “I’d say whatever you’re having, but from the looks of it, it might kill me.”

  “How about a mojito?”

  “If you can get Naelle to make one.”

  Naelle already had an eye on him, so it wasn’t hard to get her attention. Although it did take some haggling to get her to make a mojito. Reinier would have to take a look at her gin still later.

  “So, tell me, how does one find such a masculine mirror in Kourou?” Reinier asked.

  “Special order. The store was overstocked with black-framed and silver-framed mirrors. But the owner likes me, and managed, as a favor, to secure that pretty pink one for you. I would’ve gotten you a matching pink eye-patch, but they were on back order.”

  “That’s just a little neurological trick. By selectively presenting information to the left eye, which is connected to the right hemisphere, I’m hopefully tickling the anterior superior temporal gyrus, the part of the brain responsible for insight.”

  “Forced right brain thinking?! I guess the one-eyed man is also king in the land of the lab.”

  Reinier put the mirror down on top of the pile of wrapping paper on the table and then leaned back and stared at her.

  Elle had long been inoculated against the gazes of men. They were as commonplace to her as a handshake or a sneeze. Still, in this moment she felt her cheeks warm as blood rushed into them. Something about the way he looked at her. It wasn’t aggressive. It wasn’t ogling. There was no agenda behind his eyes. They were devoid of bias or preconception. He just seemed open and observant and curious. He was present to her. She met his gaze.

  “What if I wanted to tell you a secret?” he asked.

  Her mouth opened, but no words came out. She had not expected this question.

  “Here,” he said, tearing off a piece of wrapping paper. “Pick a number, write it down, and don’t tell anybody what it is.”

  She took the paper from him without realizing, still more confused than anything. He dug two pens out of the inside pocket of his tweed sport coat, handing one to her.

  “I’ll do the same,” he said as he wrote down seventeen. He frowned at his choice. Scratched it out and wrote seven. “For ease’s sake, you might want to pick a reasonably small number that’s not zero or one. Those numbers tend to misbehave in calculations.”

  The word calculations seemed to snap her out of her daze. She smiled, looked at her piece of paper, and wrote down four.

  He smiled at her. “Ok, so you and I each have our private numbers. Nobody but you knows yours, and nobody but me knows mine. Now suppose we’re sitting next to a man who’s had a little too much to drink and in his inebriation shouts out Sophie-Germain primes—”

  “What’re those? Remember I’m the Centre’s face, you’re the brains.”

  “It’s just a prime number that is both prime itself as is the number you get when you multiply it by two and add one. So, eleven is a Sophie-Germain prime.”

  “Because eleven is prime as is two times eleven plus one.”

  “Precisely. Not just face after all.” He smiled.

  She looked down at her paper.

  “Ok so our inebriated friend hiccups out eleven and,” he shrugged, “three. Everybody in the bar hears him say those two numbers.” To emphasize the point, Reinier yelled to Naelle, “Eleven and three!”

  “Eleven and three what?” Naelle challenged.

  “Just that, eleven and three.”

  “I’m making the mojito. Timing me only makes me go slower,” she says, while muddling the mint in the glass.

  Reinier turned back to Elle. “So now we do a little math. It’s called mod, but don’t worry about that. Let’s take our public three. Raise to the exponent of your private number.”

  This took her a moment. Three to the fourth equals, three times three is nine, times three is twenty-seven, times three, eighty-one. “Got it.”

  “Ok now figure out the remainder when you divide that number by our other public number?”

  Eighty-one, closest multiple of eleven is seventy-seven. “Got it,” she says.

  “I got mine too. Ok, now tell me the answer you got, and I’ll tell you mine. Wait.” Naelle comes over with Elle’s mojito. As she rests it on the coffee table, Reinier asks her, “Naelle, just listen to this a moment. Ok Elle, tell me.”

  “Four.”

  “Good. Mine’s nine. Did you get all that, Naelle?”

  “Course I did. You’re all spoutin’ random numbers. Eleven, three, four, and nine. Don’t you be testing Mama Naelle’s memory. It’s a-sharper than a moray eel’s teeth.” She smacked Reinier with a dishrag, and she walked back to the bar.

  “Ok, now you take my number and raise it to your private number,” Reinier instructed Elle.

  “Can I write down the math?”

  He nodded. She calculated. Nine to the fourth, 6,561.

  “It’s a pretty big number.”

  “So, and you can write down your work again, as long as you don’t show me, what’s the remainder when you divide that number by eleven?”

  Ugh, she thought. Eleven goes into 6,561 approximately 596 times. 596 times eleven is 6556. Remainder is . . . “Ok, I got it. I feel like I’m in Montessori all over again, but I got it.”

  “Me too. Now I can tell you a secret.”

  “Wait,
what? How?” she asked.

  “We both now know the same number.”

  “We do?”

  “Yes, through those calculations, we now both have arrived at the same number. We throw away our original numbers. I never know yours, you never know mine, but we now share this number in common. And only we know it. Nobody else at the bar. Not the inebriated primer, not Naelle. Just us. It’s our cipher. We use it to encode our secrets. Actually, we would do iteration upon iteration of this, but this is the basic idea of public-key encryption, cryptography.”

  She stared at him. No blushing, no self-consciousness, no attempt at flirting. She smiled. “What’s our number?”

  He rolled his eyes. “It’s five.”31

  “That’s amazing.” Her eyes widened.

  “It’s just math.”

  “Don’t be modest, it’s like, wow, it’ll be used everywhere.”

  He laughed. “I’m not being modest, and it is used everywhere, ever since it was invented in the 70s.”

  “Oh,” she said. “Well, that makes sense.” She takes a sip of her mojito. “So what’s your thing?”

  “Quantum cryptography. I exploit entanglement. What we just did is fantastic and useful, except that it’s based on classical physics—”

  “Not this again . . .”

  He laughed again. “I know, right? I do get this tunnel vision, you know, blinders on, and I just go, and it makes me, well, inconsiderate I guess.”

  “Might be the eye-patch.” She winked. “I wouldn’t call it inconsiderate. I’d just say you get focused.”

  “You are good at PR, Elle.”

  Her cheeks warmed up again at the sound of her name on his lips.

  He sighed. “How do you say egghead in French?”

  She cocked her head a moment, thinking. “In Paris, we just would call you ‘intelligent,’” she said in her heavy French accent.

  He burst out laughing. She revealed a shy grin.

  “You have a way with words.”