Why does Truecrypt ask for administrator password?

Solution 1:

TrueCrypt asks you for a password because mounting a filesystem requires superuser privileges. Do not circumvent it by allowing to run truecrypt as root without password, this is insecure as a malicious script can get elevated privileges by mounting a special-crafted container, and gain root privileges from it (e.g. setsuid binaries on in an ext2 filesystem or mounting on /).

Solution 2:

Here is a quick fix you can use:

sudo visudo 

Add the line <yourusername> ALL=NOPASSWD: /usr/bin/truecrypt and save the file. truecrypt wont ask for your admin password anymore for . It quick and dirty, probably not safe, but works.