New version John the Ripper uses GPU and cracks Office files

Developers of the password cracker John the Ripper have released a version that uses Cuda and OpenCL, with which a gpu can be put to work. More file formats are also supported.

According to the developers of the open source password cracker, 40,000 lines of new code have been added to John the Ripper since the previous version. The most important innovation in version 1.7.9-jumbo-6 is the possibility to use the GPU. For this, both Nvidias Cuda and OpenCL support is available.

The hack tool also includes support for more file formats and encryptions. For example, John the Ripper can sink his teeth into password-protected files from Office 2007 and Office 2010, while also attacking OpenDocument files. Furthermore, the tool can handle the master passwords of Firefox and Thunderbird, analyze its wpa-psk keys, and obtain passwords in OS X keychains.

According to developer Solar Designer, using the GPU to crack passwords is especially useful for wpa-psk encryption and password hashes on Unix systems. In addition, John the Ripper would also use the gpu if the speed gain is relatively small. The developer states that similar packages deliberately omit this because the speed claims are said to be insufficient. As an example, Solar Designer mentions the sha512crypt encryption used by Ubuntu. John the Ripper would achieve up to 11,000 hashes per second on a GeForce GTX 570 GPU, about five times faster than a CPU with eight cores.