Is there an feasible alternative to "kernel anti-cheat" available on Linux?
When it comes to anti-cheat on Linux, it's basically an elephant in the room that nobody wants to address.
Anti-cheat on Linux would need root access to have any effectiveness. Alternatively, you'd need to be running a custom kernel with anti-cheat built into it.
This is the part of the conversation where someone says anti-cheat needs to be server-side, but that's an incredibly naive and poorly thought out idea. You can't prevent aim-bots server-side. You can't even detect aim-bots server-side. At best, you could come up with heuristics to determine if someone's possibly cheating, but you'd probably have a very hard time distinguishing between a cheater and a highly skilled player.
Something I think the anti-anti-cheat people fail to recognize is that cheaters don't care about their cheats requiring root/admin, which makes it trivial to evade anti-cheat that only runs with user-level permissions.
When it comes to cheating in games, there are two options:
1. Anti-cheat runs as admin/root/rootkit/SYSTEM/etc.
2. The games you play have tons of cheaters.
You can't have it both ways: No cheaters and anti-cheat runs with user-level permissions.
On dedicated servers we had a self-policing community with a smaller pool of more regular players and cheaters were less of an issue. Sure, some innocents got banned and less blatant cheaters slipped through but the main issue of cheaters is when they destroy fun for everyone else.
So, for example, with the modern matchmaking systems they could do person verification instead of machine verification. Such as how some South Korean games require a resident registration number to play.
Then when people get banned (or probably better, shadowbanned/low priority queued) by player reports or weaker anti-cheat they can't easily ban evade. But of course then there is the issue of incentivizing identity theft.
And I don't think giving a gaming company my PII is any better than giving them root on my machine. But that seems more like an implementation issue.
I still had a lot of problems with cheaters during this time. And when the admins aren't on you're still then at the whims of cheaters until you go find some other playground to play in.
And then on top of that you have the challenge of actually finding good servers to go join a game with similarly skilled players, especially when trying to play with a group of friends together. Trying to get all your friends on to the same team just for the server to auto-balance you again because the server has no concept of parties sucked. Finding a good server with the right mods or maps you're looking for, trying to join right when a round started, etc was always quite a mess.
Matchmaking services have a lot of extremely desirable features for a lot of gamers.
Punkbuster was developed for Team Fortress Classic, even getting officially added to Quake 3 Arena. BattleEye for Battlefield games. EasyAntiCheat for Counter-Strike. I even remember Starcraft 1 ICCUP 3rd party servers having an anti-cheat they called 'anti-hack'.
You can still see this today with modern dedicated servers in CS2: Face-It and ESEA have additional anti-cheat, not less. Even modded 3rd party server FiveM for GTAV has their own anti-cheat called adhesive.
Like here's 2006 Punkbuster for Battlefield 2 (BEye might have been made for BF:V but Punkbuster was what I remember being used by servers). [1]
It automatically kicked on cheat detection but it didn't ban. It provided logs for admins to use for bans. It provided a way for admins to give community players the power to kick. It provided a player GUID based on CD key. It provided an online identity verification/registration system (though I don't remember anyone using this). It let admins take screenshots of players' screens.
[1] https://web.archive.org/web/20060515160425/http://www.evenba...
If you think the hate for anti-cheat is bad, just wait until you see the hate for identity verification.
I'm actually rather blown away that you would even suggest it.
At the level of privilege you're granting to play a video game, you'd need to have a dedicated gaming PC that is isolated from the rest of your home network, lest that another crowdstrike level issue takes place from a bad update to the ring 0 code these systems are running
Why not have a commissar sit behind every gamer to make sure they're not cheating?
That's a startling degree of access to give to these people for access to cosmetic micro-transactions.
But, I guess if all your friends are snorting coke in an alley, FOMO will have you right there with them.
I can just have my screen recorded and have a fake input signal as my mouse/keyboard.. or just simply hire a pro player to play in my name, and it's absolutely impossible to detect any of these.
The point is to just make it more expensive to cheat, culling out the majority of people who would do so.
FaceIT essentially has countered most modern cheats including those using DMA. https://www.faceit.com/en/news/faceit-rollout-of-tpm-secure-...
Nowadays if memory access is needed, you are looking at having to find a way to load a custom BIOS or UEFI module in a way that doesn't mess with secure boot. Even then, certain anti-cheats use frequently firing interrupts to find any unknown code executing on any system threads.
At that point you have to look at heuristics (assuming the input device is not trivially detectable vs a legit one).
However, that can obviously only be used for certain types of cheating (e.g. aimbot, trigger bot (shoot when crosshair is on person)).
Cheating isn't always about manipulating game state, especially in FPSes. There, it's more about manipulating input, ie, auto-aim cheats.
3. No humans in your multiplayer
As someone who grew up amazed at Reaper bot for Quake, I'm surprised we don't see a rennaisance of making 'multiplayer' fun by more expressive, fallible, unpredictable bots. We're in an AI bubble and I don't hear of anyone chasing the holy grail of believable 'AI' opponents.
This also has the secondary benefit of having your multiplayer game remain enjoyable even when people's short attention spans move on to the next hot live service. Heck this could kill live service games.
Then again, what people get out of multiplayer is, on some unspoken and sad level, making some other person hurt.
A gazillion dollars of VC capital says otherwise!
If we can't fight 'em, join 'em?
You could make a Linux distro with a signed boot chain and a kernel anti-cheat, then you'd mostly need to get developers on board with trusting that solution. Nobody is doing that today, even Valve.
Funny enough, macOS of all things is maybe "best" theoretical platform for all this because it does not require you to trust anyone beyond Apple. All major macOS programs are signed by their developers, so macOS as an OS knows exactly where each program came from. macOS can also attest that it is running in secure mode, and it can run a process at user-mode level such that it can't be interfered with by another process. So you could enforce a policy like this: if Battlefield6.app is launched, it cannot be examined by any other process, but likewise it may run in a full sandbox. Next, Battlefield6.app needs to login online, so it can ask macOS to provide an attestation saying it is running on genuine Apple hardware in secure mode, and then it could submit that attestation to EA which can validate it as genuine. Then the program launch is trusted. This setup requires you to only trust Apple security and that macOS is functioning correctly, not EA or whatever nor does it require actual anti-cheat mechanisms.