QuickEncrypt uses a standard XOR crypt function with multiple keys generated from a user-specified passphrase. QuickEncrypt is not for anyone needing "strong" encryption - at least not yet. The encryption keys are not long enough. But it does provide a decent level of encryption for most people. One of the results of using the XOR crypt function is that encryption and decryption are actually the same process. That means encrypting a file twice with the same passphrase will actually leave the file unprotected. However, if you use a different passphrase, the file will then be double-encrypted, making cracking the keys that much more difficult.

A downside to that is that if someone else runs QuickEncrypt on your files and enters the wrong passphrase, the file is then encrypted with that passphrase. I will probably add some checks for this in a later version, so it checks first to see if the file is encrypted, and if so, checks to see if the keys generated by the passphrase will decrypt the file.