AvalonAC is an Minecraft anticheat designed for 1.20 and supports 1.8-1.20. It is paid offering additional subscription based paid checks.
Movement Simulation Engine
* We have a 1:1 replication of the player's possible movements
* This covers everything from basic walking, swimming, knockback, cobwebs, to bubble columns
* It even covers riding entities from boats to pigs to striders
* Built upon covering edge cases to confirm accuracy
* 1.13+ clients on 1.13+ servers, 1.12- clients on 1.13+ servers, 1.13+ clients on 1.12- servers, and 1.12- clients on 1.12- servers are all supported regardless of the large technical changes between these versions.
* The order of collisions depends on the client version and is correct
* Accounts for minor bounding box differences between versions, for example:
* Single glass panes will be a + shape for 1.7-1.8 players and * for 1.9+ players
* 1.13+ clients on 1.8 servers see the + glass pane hitbox due to ViaVersion
* Many other blocks have this extreme attention to detail.
* Waterlogged blocks do not exist for 1.12 or below players
* Blocks that do not exist in the client's version use ViaVersion's replacement block
* Block data that cannot be translated to previous versions is replaced correctly
* All vanilla collision boxes have been implemented
Fully asynchronous and multithreaded design
* All movement checks and the overwhelming majority of listeners run on the netty thread
* The anticheat can scale to many hundreds of players, if not more
* Thread safety is carefully thought out
* The next core allows for this design
Full world replication
* The anticheat keeps a replica of the world for each player
* The replica is created by listening to chunk data packets, block places, and block changes
* On all versions, chunks are compressed to 16-64 kb per chunk using palettes
* Using this cache, the anticheat can safely access the world state
* Per player, the cache allows for multithreaded design
* Sending players fake blocks with packets is safe and does not lead to falses
* The world is recreated for each player to allow lag compensation
* Client sided blocks cause no issues with packet based blocks. Block glitching does not false the anticheat.
Latency compensation
* World changes are queued until they reach the player
* This means breaking blocks under a player does not false the anticheat
* Everything from flying status to movement speed will be latency compensated
### Inventory compensation
* The player's inventory is tracked to prevent ghost blocks at high latency, and other errors
Secure by design, not obscurity
* All systems are designed to be highly secure and mathematically impossible to bypass
* For example, the prediction engine knows all possible movements and cannot be bypassed
