Folder Crypt - Version 1.6 With Folder Crypt you can password protect any Windows folder using low level encoding and standard algorithms, such as DES, Rijndael and ARC4. The program performs a true bit per bit encryption of your data. All you have to do is to supply a password or passphrase, which will be turned into a strong password by an hashing function. The encryption process is not reversibile (you can decrypt the folder only if you know the correct passphrase.) Your encrypted folder will appear as a .crypt file in place of the original folder. Opening and listing folder contents is password protected. Full international characters support.