Finding and recreating function.

[SnakeGrifter]

Hi.
I have been trying to find a way to decrypt TCP packets received from one of many servers from an MMORPG.
I know the packets contain data about location of enemies, players, NPCs etc.

Tried to capture decryption keys with wireshark, didnt go well.
Tried different encoding conversions from byte array to whatever to see if anything makes sense, got nowhere.
Tried figuring out what kind of encryption they use, didnt even know where to begin and it always pulled me way off track.
Tried a few other approaches aswell, all failures.

The current approach is using IDA pro to see if from client side, there are crypt functions.
I am a newbie at everything so i dont even know if im working with the right functions when i see them.
In the "imports" tab I see a list of functions that have to do with securing data.
I can see that theyre being called and i can see everything in assembly.

My goal is to recreate these functions, test them and then put them in the project to see if they can decrypt the packets.
Is this even possible?
How should i approach this?

1 month has passed, people are starting to reach me just to see if im alive.
Skipping many work days, losing lots of weight by skipping meals, no more daily routines, i just wake up and start looking at how to tackle this problem.
I am starting to doubt theres a way.