Have you ever desired to access your data using your usb pen as the "password"? In this post I'll explain how to do it.
What you need
1) a pen drive
2) truecrypt http://www.truecrypt.org
3) a little portable software made by me (see below)
What to do Part 1: create a Truecrypt volume with a keyfile
1) Go to http://www.truecrypt.org and press Download 
2) Download thw Vista/XP version
3) Click on TrueCrypt Setup 6.1a
4) Accept(if you want)
5) Select Extrac and click next until finished
6) Run TrueCrypt.exe
7) Select Volume -> Create New Volume
8) Create an encrypted file container and Next
9) Standard truecrypt volume and Next
10) Press Select file and write test.vm, Save, Next
11) Select the size of the volume (ex: 50MB)
12) Click Next
13) Don't put a password, but check Use keyFiles and press Keyfiles..
14) Now Generate Random Keyfile
15) Generate and save
16) Select kf.f as name and click ok, then Close
17) Click on Add file and select that file (kf.f)
18) Press OK, than Next
19) Select FORMAT, then, when finished, Exit
What to do Part 2: protect your volume with an usb pen
1) Copy all files, except the volume, on your pen drive, so that the folder content looks like this
2) Copy this program on the same directory
krypt.exe (364.86 kb)
This is the source if you are interested:
#Persistent
FileSelectFile, volume, , , Select the crypted volume
Run, truecrypt.exe /q /k "%A_ScriptDir%\kf.f" /v "%volume%" /e, %A_ScriptDir%
Gui, Add, Button, -gexit, Exit volume
Gui, -SysMenu +ToolWindow +AlwaysOnTop
Gui, Show,,krypt
return
exit:
Run, truecrypt.exe /q /d
exitapp
return
3) That's all
How to use your pen drive
Click on the program and select the volume. Now on Desktop -> Computer you'll find the new encrypted drive(ex: E:\). To re-protect the volume and close the session click on CLOSE and remove your pen drive.
If you want to use more than one volume, just create anothe truecrypt volume with the same keyfile kf.f.
Be carefull: don't lost the pen drive or you'll lost all your data!!!