It really is!

Hye-jin can't agree that it's a good policy the day after she got shot.

"Please be extra careful?" she opines, anxiously.

"I will be! I'm not suicidal."

"So, in what way are the body cams insufficient as protection against the mind powers?"

"They're very reactive? I mean, obviously mine did great. Just they're more for after action reports than really properly preventing mind tampering in the moment. And I'll admit I've ever slacked on footage review, because it kind of sucks to review video and audio files of yourself constantly, something subtle could get past our notice. ... I guess that's an argument for hiring out, isn't it."

"I'd really prefer not hiring out if we can avoid it. Not just due to, to, uh, comfort, like, mine and Hye-jin's, but also because the more people we include in this conspiracy, even remotely and, uh, compartmentalised like that, the more failure points we can have. We really don't want Kang Jaeha to know that there's more people than me, Hye-jin, Woo-young, and prez who know about everything, if we can at all avoid it."

"Can we actually avoid it?"

"We can at least delay it."

Nod.

"I don't know what his, uh, cyber intelligence network is like, but he does have a lot of money to throw around, and has had literal years to get established and entrenched. And he can just walk into spaces he shouldn't be, delete the video footage, and wipe everyone's memories of the incident. So. Yeah."

"Could you use AI for facial recognition and automatically get a notification if your body cameras see him? He has a longer range than sight, if I recall correctly, but that'd be one extra layer of security."

"...not a bad idea. Maybe voice recognition, too, he's given enough interviews and I, uh." This is uncomfortable to say. "Still have some voice messages he's sent me."

Not going to think about that too much, thanks!

"That's an excellent, idea," says Hye-jin, who understands what positive feedback is. "Though for the record I have no idea how to make that happen."

"I do. I can make it happen."

"So I think a problem we're having here with all of these proposed solutions is that 'mind effects' is really vague, and I think we'd benefit from being more concrete about what our attack surfaces actually are."

"Oh, finally decided to say productive things, have you?"

...he wants to snipe but, like, she's not wrong.

"Yeah. Sorry about, uh, all the everything before."

It kind of made Hye-jin feel better, that someone is fully on board with just killing this guy to keep them safe. She would like more of that energy in her life. She does admittedly dislike how her legitimate concerns got lumped in with Si-yeon's murder opinions. But that's more her discomfort with how Tae-gun seems to be modeling her as way more murder happy than she actually is, and only seems to be remembering the parts where she mentions that killing Kang Jaeha is on the table at all, and none of the context around them.

But that is a fight to pick after the important tactics talk.

"So part of the problem is that it's either really subtle, or really blatantly obvious? I can list some of the things he did for the round two, though, to give a good overview of what he can mess with subtly. Uh... Visuals, audio, he made me feel like my heart was racing when it wasn't - I suppose heart monitors might be an option - he invoked a false feeling of anxiety, false, uh - prickling sensation on the back of my neck? He was trying to force me to feel uneasy about being surrounded by copies of him when actually I found that kind of funny. But I think we already know his options here are 'Yes', so. I don't know how useful any of that is."

"What I'm thinking here is less what he can do, which as you say is 'yes', and more what, out of the things he can do, we're most concerned about. The top concern being the one you've mentioned before, about your powers; under what circumstances would he succeed at using you against your goals in that manner?"

(He doesn't, quite, adopt formal speech, here, but he's definitely dropping the maximally casual patterns he'd been speaking in before.)

"If I were mistaken about a dungeon break, and he made me think a civilian is a monster. Or any other kind of - putting me into a combat situation that I think is legitimate, but pointing me at the wrong thing," she answers, immediately. "I've requested to be sent into dungeons more than the standard for that reason, actually, the dungeon portal would actually effectively cut him off. So, uh. Faking that would also be bad."

He nods.

"For the purpose of this exercise, let's say we have a finite gauge of location security, and if it runs out you land in Kang Jaeha's clutches." Si-yeon's thinking in terms of bits of information necessary to determine someon's location—approximately 34 if you limit your search to the Earth's landmass and 36 if not, to a precision of ten square meters—but the majority of the time actually giving it numbers is unnecessary and you can just work through the logic. He opens a large commscreen of his own then gets a world globe there, and draws a little empty gauge next to it.

"We need to assume that this house's location is unknown to Jaeha; being here fills your gauge to some specific value." They lose a little bit more than 10 bits, just for being in Korea and not in a big city; he rotates the globe and highlights Korea, writes a "?" on it, and fills the gauge to about two-thirds. "Whenever you teleport from here, the security gauge fills some because the total number of possible destinations you could teleport to is enormous," he gets lots of arrows from Korea to around the world and fills the gage, "and empties some depending on how many people know or perceive your arrival at your destination and how compromised they are." At this point the numbers are useless, but he copy-pastes the gauge to a few possible destinations and eyeballs reasonable values for them for a couple of big cities as well as the middle of nowhere.

"Then, in addition to location security, we have control security: the extent to which Kang Jaeha is restricted in what he can do to you." Another gauge! The first one is blue, this one is red. "If that one reaches zero, he has full control of your environment and actions.

"Its relationship with location security isn't straightforward. If you have maximum location security you also have maximum control security," full gauge in the middle of the Australian outback, "but a very public and populous location also has reasonably high control security because Kang Jaeha can't get away with that much in front of too many witnesses," and a 40% filled gauge near Seoul, which had been marked as low location security. "On the other hand if you are in a completely deserted location with no witnesses that he knows precisely," and he writes Kang Jaeha's name attached to a little dot in Korea then moves him to the Australia and lowers the location gauge to zero, "that also has zero control security," and that gauge goes to zero.

"The reason I'm going into this roundabout explanation is that we shouldn't think about it in terms of trying to completely prevent Kang Jaeha any access to you; we should think about it in terms of tradeoffs between those two types of security, and about interventions that raise one without lowering the other too much, ideally at all."

...God, Si-yeon is so hot when he gets into information security.

"In these terms, the body cams are a great tool because they increase control security while sacrificing location security not at all. However, having third parties constantly review them lowers location security and it's not clear that the increase in control security outweighs that."

Hye-jin kind of wants to skip the part where the thing she's been freaking out for months about is being explained to her in a way that she finds overly roundabout.

"Right. One of the ways of countering him is teleporting to different varied locations in an unpredictable manner. That is what I did after the second time he came after me."

Which is to say: can you actually give her something actionable to work from, or are you going to just tell her things she already knows the day after she got shot? Because this is a deeply unpleasant topic to talk about at all. If it's not going to get her concrete ways to keep herself safe, instead of everyone sitting in a circle agreeing how in many ways it's improbable but not impossible for her to get gotten, then she'd really rather skip it.

"Which increases both securities but actually has the same problem you mentioned earlier, of being reactive rather than proactive, and also of relying on him not having gotten enough control of you that you fail to teleport. So those are two other dimensions to look at: reactivity, and recoverability." He writes those down, and then he adds the solutions proposed: body cams increase control security, don't touch location security, are reactive, and are recoverable; third parties looking at the cams increase control security, don't touch location security, are somewhere between reactive and proactive, and are recoverable; teleporting around after being compromised increases both location and control security but is extremely reactive and not at all recoverable.

"What would a proactive increase in location security look like? People have been discussing the idea of tightening security around portals and making everything off-limits to the media; teleport into a tent, then walk through the portal, close the dungeon, teleport out, no one's the wiser." He adds it to the list: increase in location security, decrease in control security, proactive, recoverable. "Going preferentially to dungeons abroad increases location security without decreasing control security, at least not by itself." More dungeons abroad goes on the list. "Decoys! Get body doubles, people who look like you guys, to go places, and wear disguises." Location security goes up (though by just a little bit), control security stays the same, proactive, recoverable.