Most file encryptors use methods that rely on the time taken in guessing the key number. Providing the key length is 128 bits or greater this method works well... for now. CryptIt uses a variant of Vernam encryption that can have keys the same size as the file to be encrypted. Thus, if you are encrypting a 5MB file, then you can have a 40 Million bit key! This is virtually unbreakable by any computer, especially when you consider that the file must also be checked with each combination to see if it is decrypted. Furthermore, the key file can be anything - a program, a swap file, an image of your cat or even a music file.

CryptIt also has a ability to use removable media (USB keys, CDs, floppies) as a key, further increasing the security and convenience of the method. If your needs are more simpler then you can also use a word (string), but the advantages of the Vernam method are lost then. Descriptions can be stored within the encrypted file, as well as the file name of the code. This enables the file to be, for example, EMailed to another person who has the same collection of codes as you, while not sending the actual code. Command line operation is also supported and CryptIt is written in Assembly Language for maximum efficiency.