Systems like PhoneBookFS, rubberhose and StegFS exist (or used to exist). They allow you to create volumes which can provide different data for different passwo

Systems like PhoneBookFS, rubberhose and StegFS exist (or used to exist). They allow you to create volumes which can provide different data for different passwords, with no way to know the number of available passwords in advance. (You can look at the volume size, but there is some variability relative to the total amount of data stored, so that you can't really be sure.) See http://en.wikipedia.org/wiki/Deniable_encryption http://en.wikipedia.org/wiki/Deniable_encryption.