Encrypted data is intended to be indistinguishable from random data until a correct key is provided.
This computer runs a script that will cause it to continuously create files with a size of 5 MiB.
 A random 1/3 of these files contain random data sourced from Wikipedia Encrypted with a 24 character password.  The remaining 2/3 of these files are generated as pseudo-random binary data, noise.
These two types of files are indistinguishable from each other, even under close analysis. Unless a correct key is provided they will both appear as noise.
In the UK, under the ‘Regulation of Investigatory Powers Act’, if you are thought to have had access to a key for an encrypted file in your possession that is under investigation, you can be convicted for failing to provide a key.
Every decision the macro makes is sourced from random data. This means the owner of the computer has no knowledge of which files are encrypted data and which are just noise. Even then, there is no way to know what the contents of the encrypted files are, or the passwords to the encrypted files.
 Encrypt Data: a. Save content from random wikipedia article. b. Use TrueCrypt software to encrypt saved data with 24 character password.
 Generate Random Data: a. Use “/dev/urandom” command on Terminal to generate 5 MiB of random binary data.