Resolved incompatibilities / bug fixes:

• On systems where certain inappropriately designed chipset drivers were installed, it was impossible to encrypt the system partition/drive. This will no longer occur. (Windows Vista/XP/2008/2003)

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

-- 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)

New features:

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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)
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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).
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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.
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The minimum memory requirements for the TrueCrypt Boot Loader 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. (Windows Vista/XP/2008/2003)
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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:

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On some systems, drive letters were not correctly assigned to newly mounted non-system volumes. This will no longer occur. (Windows)
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Many other minor bug fixes. (Windows, Mac OS X, and Linux)

5.0a

February 12, 2008

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:

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)