Ymer

Ymer is a high performance anti-cheat plugin.

Protect Your Server From Griefer!
Attention: It's a bit difficult to install it correctly, please read this post carefully before using it!
Introduction
So what's "Ymer"? Ymer is a plugin which can protect your server from those griefers who use hacked clients or cheating mods. About 90% of its codes were made with C++, it's compatible with Windows/Linux 64bit system.
To make sure it works efficiently, your players must install a MOD to join the server.
Ymer on bStats

• https://bstats.org/plugin/bukkit/Ymer

Ymer can protect from these cheating ways:

• Cheat with illegal mods.
• Cheat with almost all kinds of hacked clients.
• Cheat with javaagent.

Ymer CANNOT protect from these cheating ways:

• Cheat with some special resourcepacks (e.g. X-RAY resourcepack)

How does it work?
When your player's client is loading, Ymer will check every files loaded by libymer. If a file is found not in the list of SHA512.txt, then the player will be kicked from server.
Tip: You can add some "legal" mods or other files into SHA512.txt
Features

• Hard to crack!

We all know that plugins made with Java can easily be decompiled and cracked. Ymer is made with C++ and it's hard to crack.

• Less lag!

When checking files on loading the clients, it doesn't occupy the main thread and doesn't make so much lag.

• Less RAM occupied!

Ymer doesn't take much RAM occupied
The RAM it used on server is 8kb per player (so 1000 players take only 8mb RAM)
The RAM it used on client is no more than 40mb.

• It's NOT a virus!!!

Some antivirus softwares will report that it's a virus, but I swear to God it's not a virus, maybe it's because it's made with C++ and protected by tmd

• Compatible with Valkyrie!

Valkyrie is another anti-griefer plugin which made by my best friend Izzel_Aliz, Ymer can compatible with Valkyrie (stable ver. 1.2 & beta ver. 1.3)
How to install

1. move file ymer-x.x.x.jar to your server plugins folder
2. launch your server,and wait for its auto stop. Ymer will generate some files in this step.
3. move file ymer-x.x.x.jar to your client mods folder
4. launch client with forge
5. find a file named SHA512.txt
6. copy file SHA512.txt to your server plugins/ymer folder
7. launch your server again.
8. enojy!

Notice

1. it is necessary for every players to join server with ymer-x.x.x.jar mod