Skip navigation.
Home

TrueCrypt 5.1a

Free open-source disk encryption software for Windows Vista/XP/2000 and Linux!

On-the-fly encryption software which can create a virtual encrypted disk within a file and mount it as a real disk. It can also encrypt a hard disk partition or storage device, such as USB flash drive. Moreover, TrueCrypt supports plausible deniability.

Introduction

TrueCrypt is a software system for establishing and maintaining an on-the-fly-encrypted volume (data storage device). On-the-fly encryption means that data are automatically encrypted or decrypted right before they are loaded or saved, without any user intervention. No data stored on an encrypted volume can be read (decrypted) without using the correct password/keyfile(s) or correct encryption keys. Entire file system is encrypted (e.g.., file names, folder names, contents of every file, free space, meta data, etc).

Files can be copied to and from a mounted TrueCrypt volume just like they are copied to/from any normal disk (for example, by simple drag-and-drop operations). Files are automatically being decrypted on-the-fly (in memory/RAM) while they are being read or copied from an encrypted TrueCrypt volume. Similarly, files that are being written or copied to the TrueCrypt volume are automatically being encrypted on-the-fly (right before they are written to the disk) in RAM. Note that this does not mean that the whole file that is to be encrypted/decrypted must be stored in RAM before it can be encrypted/decrypted. There are no extra memory (RAM) requirements for TrueCrypt. For an illustration of how this is accomplished, see the following paragraph.

Let's suppose that there is an .avi video file stored on a TrueCrypt volume (therefore, the video file is entirely encrypted). The user provides the correct password (and/or keyfile) and mounts (opens) the TrueCrypt volume. When the user double clicks the icon of the video file, the operating system launches the application associated with the file type – typically a media player. The media player then begins loading a small initial portion of the video file from the TrueCrypt-encrypted volume to RAM (memory) in order to play it. While the portion is being loaded, TrueCrypt is automatically decrypting it (in RAM). The decrypted portion of the video (stored in RAM) is then played by the media player. While this portion is being played, the media player begins loading next small portion of the video file from the TrueCrypt-encrypted volume to RAM (memory) and the process repeats. This process is called on-the-fly encryption/decryption and it works for all file types, not only for video files.
Note that TrueCrypt never saves any decrypted data to a disk – it only stores them temporarily in RAM (memory). Even when the volume is mounted, data stored in the volume is still encrypted. When you restart Windows or turn off your computer, the volume will be dismounted and files stored in it will be inaccessible (and encrypted). Even when power supply is suddenly interrupted (without proper system shut down), files stored in the volume are inaccessible (and encrypted). To make them accessible again, you have to mount the volume (and provide the correct password and/or keyfile).

File size:
1.5 MB
License:
Free
License:
Opensource
Requirements:
Windows Vista/XP/2000/2003, Linux

TrueCrypt 5.1a Released

Improvements:

  • Faster booting when the system partition/drive is encrypted (typically by 10%).   (Windows Vista/XP/2008/2003)

  • Other minor improvements.  (Windows, Mac OS X, and Linux)



      Resolved incompatibilities:

  • On computers with certain hardware configurations, resuming from hibernation failed when the system partition was encrypted. Note: If you encountered this problem, the content of RAM may have been saved unencrypted to the hibernation file. You can erase such data, for example, by decrypting the system partition/drive (select System > Permanently Decrypt System Partition/Drive) and then encrypting it again.  (Windows Vista/XP/2008/2003)


    Remark: As Microsoft does not provide any API for handling hibernation, all non-Microsoft developers of disk encryption software are forced to modify undocumented components of Windows in order to allow users to encrypt hibernation files. Therefore, no disk encryption software (except for Microsoft's BitLocker) can guarantee that hibernation files will always be encrypted. At anytime, Microsoft can arbitrarily modify components of Windows (using the auto-update feature of Windows) that are not publicly documented or accessible via a public API. Any such change, or the use of an untypical or custom storage device driver, may cause any non-Microsoft disk encryption software to fail to encrypt the hibernation file. We plan to file a complaint with Microsoft (and if rejected, with the European Commission) about this issue, also due to the fact that Microsoft's disk encryption software, BitLocker, is not disadvantaged by this.

  • Workaround for a bug in the BIOS of some Apple computers that prevented users from entering pre-boot authentication passwords and controlling the TrueCrypt Boot Loader.   (Windows Vista/XP/2008/2003)



      Bug fixes:

  • When the system partition/drive is decrypted under Windows, the original partition table will not be restored. Note: This issue affected users who repartitioned an encrypted system drive and then decrypted it under Windows.   (Windows Vista/XP/2008/2003)

  • Other minor bug fixes.  (Windows, Mac OS X, and Linux)

TrueCrypt 5.1 Released

New features:

  • Support for hibernation on computers where the system partition is encrypted (previous versions of TrueCrypt prevented the system from hibernating when the system partition was encrypted). (Windows Vista/XP/2008/2003)

  • Ability to mount a partition that is within the key scope of system encryption without pre-boot authentication (for example, a partition located on the encrypted system drive of another operating system that is not running).   (Windows Vista/XP/2008/2003)



    Note: This can be useful e.g. when there is a need to back up or repair an operating system encrypted by TrueCrypt (from within another operating system).

  • Command line options for creating new volumes.  (Linux and Mac OS X)



      Improvements:

  • Increased speed of AES encryption/decryption (depending on the hardware platform, by 30-90%).    (Windows)

  • Faster booting when the system partition is encrypted.   (Windows Vista/XP/2008/2003)

  • When the system partition/drive is encrypted, the TrueCrypt Boot Loader is now stored in a compressed form and is, therefore, smaller. If a non-cascade encryption algorithm is used (i.e., AES, Serpent, or Twofish), the TrueCrypt Boot Loader is now small enough so that a backup of the TrueCrypt Boot Loader can be (and is) stored in the first drive cylinder. Whenever the TrueCrypt Boot Loader is damaged, its backup copy is run automatically instead.



    As a result of this improvement, the following problem will no longer occur: Certain inappropriately designed activation software (used for activation of some third-party software) writes data to the first drive cylinder, thus damaging the TrueCrypt Boot Loader. The affected users had to use the TrueCrypt Rescue Disk to repair the TrueCrypt Boot Loader. This will no longer be necessary after upgrading to this version of TrueCrypt (provided that the system partition/drive is encrypted using a non-cascade encryption algorithm, i.e., AES, Serpent, or Twofish).



    Note: If your system partition/drive is currently encrypted using a non-cascade encryption algorithm (i.e., AES, Serpent, or Twofish), a backup copy of the TrueCrypt Boot Loader will be automatically stored in the first drive cylinder when you upgrade to this version of TrueCrypt.

  • The minimum memory requirements for the TrueCrypt Boot Loader (AES) have been reduced from 42 KB to 27 KB (twenty-seven kilobytes). This allows users to encrypt system partitions/drives on computers where the BIOS reserves a large amount of memory (provided that the AES encryption algorithm is used).  (Windows Vista/XP/2008/2003)

  • Many other minor improvements.  (Windows, Mac OS X, and Linux)



      Resolved incompatibilities:

  • On some computers, when performing the system encryption pretest, Windows failed to display the log-on screen.
    This will no longer occur.   (Windows Vista/XP/2008/2003)


      Bug fixes:

  • On some systems, drive letters were not correctly assigned to newly mounted non-system volumes. This will no longer occur.  (Windows)

  • Many other minor bug fixes.  (Windows, Mac OS X, and Linux)

TrueCrypt 5.0a Released

Improvements:

  • The memory requirements for the TrueCrypt Boot Loader have been reduced by 18 KB (eighteen kilobytes). As a result of this improvement, the following problem will no longer occur on most of the affected computers: The memory requirements of the TrueCrypt Boot Loader 5.0 prevented users of some computers from encrypting system partitions/drives (when performing the system encryption pretest, the TrueCrypt Boot Loader displayed the following error message: Insufficient memory for encryption).


      Bug fixes:

  • On computers equipped with certain brands of audio cards, when performing the system encryption pretest or when the system partition/drive is encrypted, the sound card drivers failed to load.
    This will no longer occur.   (Windows Vista/XP/2003)

  • It is possible to access mounted TrueCrypt volumes over a network.   (Windows)

  • TrueCrypt Rescue Disks created by the previous version could not be booted on some computers. This will no longer occur.  (Windows Vista/XP/2003)



    Note: If your TrueCrypt Rescue Disk created by TrueCrypt 5.0 cannot be booted on your computer, please upgrade to this version of TrueCrypt and then create a new TrueCrypt Rescue Disk (select 'System' > 'Create Rescue Disk').

  • Many other minor bug fixes.  (Windows, Mac OS X, and Linux)

TrueCrypt 5.0

We are pleased to announce that TrueCrypt 5.0 has been released. Among the new features are the ability to encrypt a system partition or entire system drive (i.e. a drive where Windows is installed) with pre-boot authentication, pipelined operations increasing read/write speed by up to 100%, Mac OS X version, graphical interface for the Linux version, XTS mode, ability of the wizard to create hidden volumes within NTFS volumes, SHA-512, and more.

After four years of development, during which millions of people downloaded a copy of TrueCrypt, it is the only open-source disk encryption software that runs on Windows, Mac OS X, and Linux. The newly implemented ability to encrypt system partitions and system drives provides the highest level of security and privacy, as all files, including any temporary files that Windows and applications create on system drives (typically, without the user's knowledge or consent), swap files, etc., are permanently encrypted. Large amounts of potentially sensitive data that Windows records, such as the names and locations of files opened by the user, applications that the user runs, etc., are always permanently encrypted as well. For more information, please see http://www.truecrypt.org/docs/?s=version-history

TrueCrypt 4.3a Released

The latest stable version of TrueCrypt, 4.3a, has been released today. This is mainly a maintenance release, which, in addition to several bug fixes, introduces full support for custom screen DPI settings (applies to the graphical user interface of the Windows version of TrueCrypt).

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.