Note: It is recommended to make a backup of all important files before using the decrypter. Link to decrypter download page.  <- The decrypter will tell you if your files are decryptable, whether you're dealing with an "old" or "new" variant of STOP/Djvu, and whether your ID is online or offline. Link to instructions for using the decrypter (PDF). Link to "file pair" submission form. Link to more information about the decrypter. <- Article at BleepingComputer.co