DiskCryptor download is a tiny 750Kb, after installing it you will need to reboot the computer, you might notice that its 64bit drivers come signed by the ReactOS foundation a non for profit organization assisting open source projects not able to acquire an expensive signing certificate to distribute Windows 64bit drivers.
Encrypting my Windows 7 Home Premium 64bit OS, with a fairly powerful Intel i5 2200Hz (quad core) absorbed very low CPU, a steady 7% of the available resources, it took me 20 hours to encrypt a 1TB hard drive, it would have been considerably quicker using just the AES algorithm instead of the cascade algorithm I selected.
DiskCryptor lets you know how long it will take to encrypt your operating system, you can still work with your computer while it is being encrypted, I advice you to temporarily disable power management in Windows and set it to always on, Windows will not notice the hard disk being encrypted and send the OS into hibernation mode believing the computer is inactive, if this happens full disk encryption will stop and only resume once you switch the computer back on, I have found this problem to occur with both DiskCryptor and Truecrypt, more of a Windows problem than to do with the full disk encryption software.
Diskcryptor lets you benchmark the encryption ciphers (Tools>Benchmark) if you have a low spec CPU and are in a hurry you can choose the cipher that performs best in your system, AES was the quickest for me, by quite a lot of difference in contrast with Twofish and Serpent, once the OS has been encrypted it doesn’t matter what cipher you used to encrypt it, performance will be the same. You can benchmark ciphers in Truecrypt too but since only AES can be used for full disk encryption there is no point in doing it.
Truecrypt will ask you to enter your password after rebooting your computer before encrypting your operating system, DiskCryptor will not, it assumes you entered the passphrase correctly twice as asked and did not make any mistake. When using special signs in your password be aware that in booting up your computer the keyboard has a US layout that will not correspond with a non US keyboard, I searched for a photograph of US keyboard layout on the Internet to make sure there would be no mistakes about what keys to pres.
Unlike Truecrypt, DiskCryptor bootloader is highly configurable, I have my own (Ascii) logo at logon and I instructed DiskCryptor to time out after 30 seconds of inactivity at which point the computer reboots, other options like halt and exit to BIOS are possible. Using DiskCryptor keyfile for full disk encryption is something possible and not supported by Truecrypt, a keyfile will thwart dictionary attacks on your passphrase but this keyfile can not consist of anything it has to be a 64 byte file generated by DiskCryptor.
Windows 7 FDE specific problem
Unlike Vista, XP and lower Windows versions, when you use a whole disk encryption product on Windows 7, or installing a dual boot, you will notice that Windows 7 automatically creates a 100MB system reserved partition, 24MB contains actual data the rest is there for future use like Bitlocker or system restore, this partition is hidden by Windows and only visible using a live CD or through DiskCryptor or Truecrypt interface.
Windows 7 system reserved partition contains some necessary boot files, do not attempt to encrypt Windows 7 system reserved partition like I did because the computer will not boot! There are hacks around to merge that partition with the main Windows 7 operating system, I managed to do it partioning the hard disk with PartedMagic before installing Windows 7 and ignoring Windows installation DVD asking me to create the system reserved partition, everything worked fine until I fully encrypted Windows 7 without the system reserved space and the computer refused to boot.
If you would like to use whole disk encryption in Windows 7 there is no choice but to give in and allow Windows to create the unencrypted 100MB system partition, this shouldn’t be a problem regarding data leakage, you can view the files it contains with a live CD, I managed to see a bootsect.bak file, bootmgr, and System Volume Information folder and a few others with no obvious danger.
Truecrypt vs DiskCryptor comparison table
|Open source license||Truecrypt own license||Standard Linux GPL license|
|Forces you to burn a recovery CD||YES||NO (optional)|
|Works with RAID volumes||YES||YES|
|Hidden operating system||YES||NO (pseudo)|
|Cross platform (Windows, Linux and MAC)||YES||NO|
|Option of cipher for full disk encryption||AES,Twofish,Serpent & cascades||AES,Twofish,Serpent & cascades|
|Supports keyfiles for full disk encryption||NO||YES|
|Can place bootloader on external device||NO||YES|
|Can create single encrypted containers||YES||NO|
|Portable mode||YES (admin rights)||NO|
|Encryption of external devices (USB,etc)||YES||YES|
DiskCryptor does not support the hidden operating system feature that Truecrypt has but allows you to install the bootloader on an external device, ie. USB thumbdrive or CD-Rom, that is where the files giving away that the operating system has been encrypted and what software has been used for that are stored, if anyone seized your hard drive it would be possible to claim that it has been wiped clean as no identifiable information can be extracted from the HDD other than random data and there is no boot loader.
Plausible deniability appears more sound than Truecrypt hidden operating system, if you give away the password for the non hidden OS in Truecrypt, the timestamps and las activities could give away that the computer has not been used for a long time.
A computer with no operating system and a wiped hard disk will look very suspicious, claims that it was wiped the day before would be held with incredulity but hard to prove it didn’t happen. Even better, I came across a thread in DiskCryptor forums to have a dual OS system where one of the Windows OS will only boot with the USB thumbdrive plugged in and when not present the other OS will boot, this set up makes one of the partitions look like random data and not like 2 operating systems on one hard disk.
Conclusion Truecrypt vs Diskcryptor
If you have a tablet or netbook without a CD-drive go for DiskCryptor because Truecrypt forces you to burn a recovery CD (there is a work around using CD-drive virtualization software, i.e. Alcohol 120% or using the command line /noisocheck).
If you would like to be able to open encrypted external devices using Linux or MAC go for Truecrypt as DiskCryptor is a Windows only program, if you want to create single encrypted containers go for Truecrypt as DiskCryptor can’t do that.
Something in which Truecrypt beats DiskCryptor is in documentation, Truecrypt manual is very complete and DiskCryptor consists of an incomplete online Wiki, DiskCryptor can make up for this showing off the ‘Blue Screen’ feature, a way to quickly crash your fully encrypted computer allowing you to set the quick emergency shutdown to any hotkey shortcut you like.
Security wise, both Truecrypt and DiskCryptor have the same credentials with their source code open to scrutiny and none of them reviewed by any qualified cryptographer, overall, DiskCryptor has more configuration features than Truecrypt, and Truecrypt is better at cross platform compatibility.