You may have trouble finding a free implementation of the SEAL cipher as IBM owns the two patents that cover it.
Have a look at
Bouncy Castle[
^] which has a version written in C# that you can use in your VB.Net projects.
If you want it for a NON-commercial use have a look at
LLCryptoLib[
^], this is free for non-commercial use.
Haven't heard of the dragon cipher unless you are talking about the serpent cipher which is a part of Bouncy Castle.