On item duplication exploits and how to prevent them

Hello, first of all, if you're Webzen or a private MU Online server owner or developer, don't take this post as a threat. These item duplication examples which I will describe are known to me since many years. As you might imagine a lot of other people may know this…

About game server architecture patterns

Hey there, I found a really nice blog about game server architectures: https://gameserverarchitecture.com If I would categorize the original MU Online game server into one of the mentioned architecture patterns, it's probably mostly the monolithic one, with some slight signs of the map centric pattern in case of…

Loading complex data with PostgreSQL JSON functions

Problem With an extension of initialization data, where I added definitions of NPCs and Monsters and their spawn points to about 10 game maps, I noticed that the time to start the server went up dramatically - from ~13 seconds to over 1 minute. The reason was, that my strategy…

MUnique OpenMU Network Analyzer

Hey people, today I release a little tool to analyze network traffic between server and client which use the mu protocol. The cool thing is, the packet structures are defined in xml files, so it can be extended like you wish. Changes on this xml files also work on-the-fly -…

A closer look at the MU Online packet encryption

in the past days I wondered why some parts of the encryption and decryption keys for the network packet encryption (aka SimpleModulus) are actually the same. So I tried to dig a bit in the SimpleModulus algorithm and the usage of these keys. Lets see how this keys (e.g.…