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Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

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Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#91

Post by vitiral »

hot_gril wrote: post #47
bee_rider wrote: post #7

Pretty cool exploit. The idea of a free for all bug abusing server is pretty neat, a whole ‘nother level of the game. I guess this is what “actually fighting” (rather than just using in-game battling mechanics) would look like if the metaverse really happened ever.

An in-between is Super Smash Bros Melee, where a lot of tournament-legal ingame tactics rely on bugs. But only ones you can exploit manually with a regular controller, not actual hacking, and also one exploit called Wobbling got banned in 2019 (note that this is a 2001 game).

In those cases the bugs are more like advanced fighting moves. I don't think item dup or insta-kill bugs would be allowed, even if they did exist.

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#92

Post by bee_rider »

hatsunearu wrote: post #17
bee_rider wrote: post #7

Pretty cool exploit. The idea of a free for all bug abusing server is pretty neat, a whole ‘nother level of the game. I guess this is what “actually fighting” (rather than just using in-game battling mechanics) would look like if the metaverse really happened ever.

the combat in 2b2t does not look like regular minecraft either. because of a long history of duped high value items, PvP is just simply spamming ender crystals which deals massive damage when broken, and the defense is just how many "totems of undying" you have which absorbs lethal damage. of course all the hacked clients automate placing ender crystals, reloading totems and identifying weak/strong locations so you'r…

That’s what I think is interesting about it, it looks like (from the outside at least; for all I know it could be super boring to play) a new system on top of the old one that obviates some of the old mechanics by ramming them to infinity/zero, but other mechanics emerge as a result.

What’s the difference between a weak and strong location?

I could imagine funny evolutions over time, just a random thought, if everyone is running a “glass cannon with lots of 1-hit protection” build, then I guess if players had to pick between fast/little attacks and big/slow ones, they’d favor the former. If everyone is walking around with little attacks just intended to trigger the 1-hit protections on their fellow glass cannons, then actually using the in-game armor system might turn those one hits into two-hits, making it relevant again. If the systems were properly tuned, (it could be exponentially difficult to gather 1-hit protections and extra lives, so turning those 1-hits into 2-hits could be really valuable), mechanics could be saved from obsolescence in interesting ways.

I’m not describing Minecraft at this point, just spitballing. It would be interesting to see a game designed with this evolution of “things being broken” taken into account, though. I guess that’s what Magic the Gathering is, hahaha.

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#93

Post by asddubs »

zzzzzzzzzz10 wrote: post #38
asddubs wrote: post #10

Earlier quoted context omitted.

I also quite liked the idea of a true anarchy server (from a gameplay perspective), but on 2b2t in practice this looked like a lot of the n-word being said in chat, so I stopped playing.

You can avoid this using chatfilters. Players who spam slurs are not worth talking to anyway. But I agree that there are far better anarchy servers than 2b around.

Yeah, I'm good just not hanging out in the same place as people like that

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#94

Post by hot_gril »

vitiral wrote: post #91
hot_gril wrote: post #47

Earlier quoted context omitted.

An in-between is Super Smash Bros Melee, where a lot of tournament-legal ingame tactics rely on bugs. But only ones you can exploit manually with a regular controller, not actual hacking, and also one exploit called Wobbling got banned in 2019 (note that this is a 2001 game).

In those cases the bugs are more like advanced fighting moves. I don't think item dup or insta-kill bugs would be allowed, even if they did exist.

Surprisingly none of those bugs have been found, but yeah they'd be banned. The weirdest thing people actually use is the yoyo glitch, which allows Ness to hit a player with a powerful move from anywhere on the map, but it's hard enough to execute that it's not OP.

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#95

Post by Retr0id »

kbolino wrote: post #89
Retr0id wrote: post #86

Earlier quoted context omitted.

Modern CSPRNGs can generate numbers at GB/s, I find it hard to believe it would slow the game down in a measurable way. The "right" solution you describe sounds overcomplicated and error-prone (now you need to think carefully about which domains are separated) compared to just using a CSPRNG.

We may be at the point where CSPRNGs are viable for video game randomness, but that wasn't the case 10+ years ago especially when factoring in compatibility with 20-year-old hardware (high-end PCs from ca 2004 could play Minecraft). Even so, a non-crypto PRNG can generally compute a new random number in 2-4 ALU ops. With SIMD optimization, that can amortize to under 1 cycle per byte, which means it takes under a nano…

chacha12, a construction that's been around in one form or another since the '00s, runs at well under 1 cycle per byte on good hardware and still plenty fast on "bad" hardware https://bench.cr.yp.to/results-stream.html (iiuc just using SIMD, no special acceleration)

But it doesn't really matter what things were like when the code was first written, it's about how it could be fixed in the present.

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#96

Post by hatsunearu »

bee_rider wrote: post #92
hatsunearu wrote: post #17

Earlier quoted context omitted.

the combat in 2b2t does not look like regular minecraft either. because of a long history of duped high value items, PvP is just simply spamming ender crystals which deals massive damage when broken, and the defense is just how many "totems of undying" you have which absorbs lethal damage. of course all the hacked clients automate placing ender crystals, reloading totems and identifying weak/strong locations so you'r…

That’s what I think is interesting about it, it looks like (from the outside at least; for all I know it could be super boring to play) a new system on top of the old one that obviates some of the old mechanics by ramming them to infinity/zero, but other mechanics emerge as a result. What’s the difference between a weak and strong location? I could imagine funny evolutions over time, just a random thought, if everyon…

> What’s the difference between a weak and strong location?

IIRC ender crystals can only be placed on bedrock, and a lot of PVP happens on the bombed-out terrain that goes all the way to bedrock.

The weak terrain in the bedrock are locations where it requires multiple jumps to get out of, iirc

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#97

Post by gu5 »

hatsunearu wrote: post #96
bee_rider wrote: post #92

Earlier quoted context omitted.

That’s what I think is interesting about it, it looks like (from the outside at least; for all I know it could be super boring to play) a new system on top of the old one that obviates some of the old mechanics by ramming them to infinity/zero, but other mechanics emerge as a result. What’s the difference between a weak and strong location? I could imagine funny evolutions over time, just a random thought, if everyon…

> What’s the difference between a weak and strong location? IIRC ender crystals can only be placed on bedrock, and a lot of PVP happens on the bombed-out terrain that goes all the way to bedrock. The weak terrain in the bedrock are locations where it requires multiple jumps to get out of, iirc

Adding on to this, explosions deal significantly more damage if your whole player is exposed - so one block holes where the bottom half of the player hitbox is covered by bedrock on all sides are usually marked by hacked clients

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#98

Post by pbsd »

tptacek wrote: post #61
chc4 wrote: post #15

LLL lattice reduction is the same algorithm that can be used for cracking PuTTY keys from biased nonces from the CVE a few days ago. 'tptacek explained a bit about the attack (and links to a cryptopals problem for it, which I can almost pretend to understand if I squint) https://news.ycombinator.com/item?id=40045377 In a similar vein, the SciCraft minecraft server had a creeper farm which used some sort of black magi…

Sean and Kelby do a much better job of describing what LLL is, but this is maybe the best explanation of why LLL is that I've ever read. In all three cases, you only need basic linear algebra, if that (Kelby wants you to grok Gram-Schmidt, which is like just before the midterm of an undergrad linear algebra 101). I really don't have words for how great this post is. It made my week. Later A really concise explanation…

Personally I think https://crypto.stackexchange.com/a/86548 is a better answer. It turns the LCG state recovery into a hidden number-like problem, and works out the solution that way. It is easy to go from there to (EC)DSA key recovery.

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#99

Post by hot_gril »

chii wrote: post #71
hot_gril wrote: post #48

Earlier quoted context omitted.

The problem is, the optimal hacks usually don't make the game fun. It becomes a war of attrition.

> don't make the game fun the fun is no longer the game in an anarchy server. It's in beating other play's strategies - which actually makes it quite close to a real war in the physical world. For example, the 2b2t minecraft wars between factions involve logistics, misinformation and intelligence (such as spies, fakes etc). It's no longer just minecraft. But that's what makes it fun and interesting.

Yeah but that's not fun, that's tedious work 99% of the time that culminates in some rare fun.

Re: Randar: A Minecraft exploit that uses LLL lattice reduction to crack server RNG

#100

Post by hot_gril »

lupusreal wrote: post #83
hot_gril wrote: post #36

Earlier quoted context omitted.

When I was a kid, I ran a public server with Logblock and anticheat but no other plugins, so it was basically vanilla for anyone who wanted to play nice. People loved it.

Public servers with e.g. coreprotect for rollbacks are still around. Most people play nice, but when somebody doesn't their acts can be reverted without impacting anybody else. It's a lot of fun if you can get the right team of admins/janitors to keep it running.

Maybe, but back in high school, it was very hard to find those. Especially with things advertised as "vanilla" or "semi-vanilla" actually having tons of crap installed.
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