VIE Encryption
From ASSS Wiki
The original VIE SubSpace clients utilized a encryption routine which obscures the game protocol from casual observers. It is generally considered a weak algorithm [1][2] since the implementation is well known.
Common language implementations can be found in several open source projects. For example, a Java implementation of the encryption routines can be found in TWCore, likewise, a C implementation in ASSS and finally a C++ implementation in MERVBot.