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Security Requirements and Precautions 
IMPORTANT: If you want to use TrueCrypt, you must follow the security requirements and 
security precautions listed in this chapter. 
The sections in this chapter specify security requirements for using TrueCrypt and give information 
about things that adversely affect or limit the ability of TrueCrypt to secure data and to provide 
plausible deniability. Disclaimer: This chapter is not guaranteed to contain a list of all security 
issues and attacks that might adversely affect or limit the ability of TrueCrypt to secure data and to 
provide plausible deniability. 
Data Leaks 
 
When a TrueCrypt volume is mounted, the operating system and third-party applications may write 
to unencrypted volumes (typically, to the unencrypted system volume) unencrypted information 
about the data stored in the TrueCrypt volume (e.g. filenames and locations of recently accessed 
files, databases created by file indexing tools, etc.), or the data itself in an unencrypted form 
(temporary files, etc.), or unencrypted information about the filesystem residing in the TrueCrypt 
volume. Note that Windows automatically records large amounts of potentially sensitive data, such 
as the names and locations of files you open, applications you run, etc.
In order to prevent data leaks, you must follow these steps (alternative steps may exist):
• If you do not need plausible deniability:
o
Encrypt the system partition/drive (for information on how to do so, see the chapter 
System Encryption) and ensure that only encrypted or read-only filesystems are 
mounted during each session in which you work with sensitive data. 
or, 
o
If you cannot do the above, download or create a "live CD" version of your operating 
system (i.e. a "live" system entirely stored on and booted from a CD/DVD) that 
ensures that any data written to the system volume is written to a RAM disk. When 
you need to work with sensitive data, boot such a live CD/DVD and ensure that only 
encrypted and/or read-only filesystems are mounted during the session. 
• If you need plausible deniability:
o
Create a hidden operating system. TrueCrypt will provide automatic data leak 
protection. For more information, see the section Hidden Operating System. 
or, 
o
If you cannot do the above, download or create a "live CD" version of your operating 
system (i.e. a "live" system entirely stored on and booted from a CD/DVD) that 
ensures that any data written to the system volume is written to a RAM disk. When 
you need to work with sensitive data, boot such a live CD/DVD. If you use hidden 
volumes, follow the security requirements and precautions listed in the subsection 
Security Requirements and Precautions Pertaining to Hidden Volumes. If you do not 

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use hidden volumes, ensure that only non-system partition-hosted TrueCrypt 
volumes and/or read-only filesystems are mounted during the session.