CryptIt is a Windows software that is designed to use conventional XOR encryption on keys that are the same size as the file to be encrypted. The program is intended for advanced users and offers various features that allow for a high level of security.

One of the key features of CryptIt is its use of XOR encryption, which relies on the theory of computational security. This method of encryption is considered to be secure because it is difficult to factorize the key, making it difficult to decrypt the file. However, as computing power increases, the difficulty of key factorization may decrease, making XOR encryption less secure. To address this, CryptIt uses keys that are the same size as the file to be encrypted. Furthermore, if an unpredictable file that is the same size as the original file is used, this is known as a one-time pad and it is considered to be completely unbreakable, even to computers 1000 years from now.

CryptIt also offers several convenience features. The program can automatically use pad files generated by the program GigAlarm, generate key files, and analyze the suitability of the chosen key file. Additionally, the program supports multi-user setups and can be run without any problems on a low privilege login and Windows Vista.

The program is also small and memory efficient, with the program itself being around 50KB. It can also be run from a USB key and does not require installation, making it easy to use on the go. The installation process is straightforward, and the program can be easily removed using the "Add/Remove Programs" option in the Control Panel.

Overall, CryptIt is a powerful and secure encryption software that offers advanced features for users who require a high level of security. The program's use of XOR encryption and one-time pad, along with its convenience features, make it a solid choice for anyone looking for a reliable encryption software. However, it's important to note that the program is intended for advanced users, so if you're looking for an easy encryption software, you may want to look elsewhere.