These are various attempts to parallelize John the Ripper with the use of MPI. While these hacks might work, I find them unsuitable for practical use. In fact, in my opinion MPI and other generic parallel processing libraries are not appropriate for creating a parallelized version of John the Ripper that would be suitable for most end users (typical system administrators, etc.) There are numerous bugs in the patches and incorrect statements in the accompanying reports. Thus, this collection is made available primarily for others who might want to similarly enhance (hack) John the Ripper with MPI or otherwise, for fun and/or as a part of their academic career. ;-) Having that said, I'd like to thank the authors of these patches for picking John the Ripper for their research and for making the patches and reports publicly available (or for granting me the permission to do so). Update (2008, 2009): John Anderson's implementation found under 2009-bindshell/ as well as at http://www.bindshell.net/tools/johntheripper is actually a maintained one (for two years now), with support provided via a mailing list. You may give that one a try. Update (2010): Magnum, P.I. has further updated the above patch, now found under 2010-magnum. Update (2011, 2012): Magnum's patch is now integrated into -jumbo, so -jumbo is what you should use (if you want to use MPI at all). You will need to enable MPI by uncommenting two lines in Makefile. The John_the_Ripper_on_a_Ubuntu_10.04_MPI_Cluster*.pdf files were downloaded from http://www.petur.eu/blog/?p=59 - you might want to check that blog entry out for possible new revisions and comments. Please also refer to the wiki page at http://openwall.info/wiki/john/parallelization Solar Designer