Cryptography is that area of expertise which deals with secret writing, the art or science of storing information in a form which hides it from those not meant to see it, yet allows it to be revealed when needed. Cryptosystem ME6 is a software program which encrypts information stored in data files so that it can be read only by someone who knows the encryption key which was used to encrypt that data. The encryption key is a word or phrase given to the program which it uses to scramble the information in a way which is unique for that key. Once encrypted, the data is secure from unauthorized access, since anyone who does not know the key cannot decrypt the data. When Cryptosystem ME6 is used to recover the data the original key must be specified. If the correct key is supplied then the data is restored to its original form.

Cryptosystem ME6 uses a private (or symmetric) key encryption system. Data is encrypted using a key which is a phrase (which can be up to 64 characters long) or a sequence of 64 random bytes. Without this key the encrypted files appear to consist of meaningless bytes and the information in them is safe from prying eyes.

Files are normally compressed before encryption. There is no limit (except available disk space) on the size, the type or the number of files which can be encrypted in a single operation with ME6.

The encryption process in Cryptosystem ME6 uses pseudo-random number generators, a secure hash function (the MD5 Message Digest Algorithm) and plaintext feedback, combined in a way to ensure the security of the encrypted data. Data encrypted using ME6, even when subjected to statistical analysis, appears to consist of random bytes, providing no information.