The aim of this thesis is to create an extension of the Fitcrack tool, which will recover passwords from disk volumes encrypted by TrueCrypt. The introduction part describes the Fitcrack tool which is used for password recovery and supports many different formats of files, and OpenCL framework which is used for computation acceleration. The thesis also deals with the TrueCrypt tool, and its possibilities of use, encrypted disk volumes analysis and cryptographic algorithms used by TrueCrypt to encrypt disk volumes. Furthermore, the work includes a concept and implementation of the Fitcrack module which will be used to recover passwords from disk volumes encrypted by TrueCrypt. At the end of the work we can see results of our experiments that...