VB.NET encryption/decryption

[boku]

Using the following characters ONLY

abcdefghijklmopqrstuvwxyz
ABCDEFGHIJKLMNOPQRSTUVWXYZ
0123456789
~!@#$%^&()_+`-=[];',.{}

I need a decent algorithm to encrypt a textbox string which holds a file name and extension that must not be readable by human eyes i.e.

"File.txt"

"Gd7&.@0x"

I also have a textbox where the user can set a password so that the filename and extension can also be decrypted back to the original file name.

Offers and time required please.

[dee-u]

Have you tried searching the forums on how to do it?

[boku]

I don't have the time to search around and look for it and then to make sure it all works etc, I've got a lot to do at the moment which is why I would like a quick bang thank you mam solution to it...