DiskCryptor is the only truly free solution, provided under GNU General Public License (GPLv3), which offers encryption of all disk partitions, including the system partition. The main criteria for open-source software is the availability of its source code under one of the open source licenses. The only open-source alternative to DiskCryptor that has comparable features is TrueCrypt. However, because of the restrictive license under which TrueCrypt is provided — the TrueCrypt Collective License — TrueCrypt cannot be classified as a truly free software, as it places limits on the use and modification of its source code by developers. There are other alternatives with similar functionality, but they are fully proprietary ones, which makes them unacceptable to use for protection of confidential data.

Program features

* Encryption of system and bootable partitions with pre-boot authentication.
o Full support for dynamic disks.
o Support for disk devices with large sector size, which is important for hardware RAID operation.
o Automatic mounting of disk partitions and external storage devices.
o Broad choice in configuration of booting an encrypted OS. Support for various multi-boot options.
* High performance, comparable to efficiency of a non-encrypted system.
o Support for hardware cryptography on VIA processors (PadLock extensions for hardware AES acceleration).
o Support for hardware AES acceleration (AES-NI instruction set) on new Intel CPUs.
* Transparent encryption of disk partitions.
o Choice to select an encryption algorithm (AES, Twofish, Serpent), including their combinations.
* Full support for external storage devices.
o Full support for encryption of external USB storage devices.
o Option to create encrypted CD and DVD disks.
* Full compatibility with third party boot loaders (LILO, GRUB, etc.).
o Option to place boot loader on external medium and to authenticate using the key medium.
o Support for key files.
* Support for hotkeys to dismount partitions, initiate emergency system stop, etc.
* Optional command-line interface (CLI).