Comment by surajrmal 2 days ago
Unpopular opinion, but we would be better off with a single open trusted implementation of anti cheat (aka drm) which can attest whatever requirements are desired by the game is met. The only real problem is that it would likely be limited to approved kernel images and someone would need to own that validation and signing infrastructure, but you could imagine having multiple trusted entities have this role.
> Cheating is a meat space problem and there is no technical solution to it
Cheating is an arms race - the number of people who are willing to run a second computer with DMA connected to a single machine is vastly smaller than the number of people who are wiling to download a dodgy file from the internet and run it.
> Ultimately it comes down to checking if metrics like reaction speed are humanly possible, but a rootkit is not really needed for that.
If it was that easy, cheating would be a solved problem. An awful lot of play is "I know the reload time is 0.75s, so they're going to appear when they've reloaded" - that's way beyond human reaction time. And that's at "mid level" play - at gold/sliver levels in league of legends knowing cooldowns is considered base knowledge. At higher levels of play, _all_ of your players are statistical outliers.
This hasn't been true for a very long time. The kind of cheats that can survive even very basic anticheat for a long time cost a decent amount of money on subscription basis. Most cheaters by volume pay quite a chunk of change to cheat.
> Kernel anticheat is not really effective because it can be circumvented on the hardware level, for example using direct memory access with a second computer and screen to show the hidden game state.
Incorrect. DMA (direct memory access) is and can be prevented [1] and detected [2].
[1] https://www.faceit.com/en/news/faceit-rollout-of-tpm-secure-...
[2] https://community.osr.com/t/detecting-pcie-dma-based-cheatin...
Once again back to another arms race. Assuming that your operating system doesn't allow any bad drivers (Windows does NOT do this) physical access to the hardware is just a function of time and money to get direct access to the memory
https://x.com/danielgenkin/status/1989003973429268974?s=12
Something like TEE.fail can be used to read encryption keys for network traffic then a MITM proxy can display player information easily on a second PC, you will never be able to reliably detect this
> Assuming that your operating system doesn't allow any bad drivers (Windows does NOT do this)
Windows eventually tends to revoke the certificate of vulnerable drivers. And prior to that, anti-cheats will flag the signature and prevent booting or outright ban for egregious ones.
> Something like TEE.fail can be used to read encryption keys for network traffic
So, encrypt the memory well then? Also, that attack slows down RAM to 3200 MT/S and is infeasible for game cheating. Maybe if you could make a custom ram stick with an ASIC on it, which would cost millions on millions of dollars to keep up with DDR5, you could capture encrypted bits and crash your system pretty often.
I don't consider it an arms race if you can prevent cheating to 10s of people in a million-player game. That's noise at best.
You can still do DMA cheating with IOMMU enabled. There are quite a few relatively widespread bugs with IOMMU that allow you to bypass it, for example https://cloud.google.com/blog/products/gcp/fuzzing-pci-expre.... So to be able to actually do IOMMU DMA protection you need to be willing to ban many popular devices. That may be viable for FACEIT and ESEA but it won't be for 99.9% of anticheat deployments.
The detection for DMA cheating is based on the DMA engines being unable to emulate 1:1 the actual behavior the hardware ID would be expected to have. This can be fixed by simply doing that properly.
But even besides that, DMA through PCIe is just one hardware cheat that fits a separate thread model and therefore has some countermeasures.
There are much more robust methods you can use, for example a PCIe interposer between the OS and GPU, or simply direct memory interposes if you want to do DMA without the protections afforded by the PCIe implementation. There are interposets along with machinery to get along memory encryption and other obfuscations that can be made for around 100$.
This is theoretically possible, but I don't think most cheaters would have the equipment or skill to do this. Cheating is only rampant in games where people can just buy and download cheats... if it requires a lot of skill and hardware, it won't be a big issue.
It's not just theoretically possible, you can buy kits that do this already.
I'm not sure this is an unpopular opinion. I've seen it suggested multiple times, and IF done correctly (open/transparent) would solve most of the complaints with the ring-zero anti cheats. Still won't solve every cheat, especially hardware, social and perhaps good VMs. I would require the app/game to disclose what it requires to be true.
Kernel anticheat is not really effective because it can be circumvented on the hardware level, for example using direct memory access with a second computer and screen to show the hidden game state.
Cheating is a meat space problem and there is no technical solution to it. Thats why in tournaments there are referees standing behind the players. Ultimately it comes down to checking if metrics like reaction speed are humanly possible, but a rootkit is not really needed for that.