apgbfm - APG Bloom filter management program
apgbfm -f filter -n numofwords
apgbfm -f filter -d dictfile
apgbfm -f filter -a word
apgbfm -f filter -A dictfile
apgbfm -f filter -c word
apgbfm -f filter -C dictfile
apgbfm -i filter
is used to manage Bloom filter that is used to restrict password
generation in APG
pasword generation software. Usage of the Bloom
filter allows to speed up password check for large dictionaries and has some
The idea to use Bloom filter for that purpose is came from the description of
project OPUS: Preventing Weak Password Choices
Purdue Technical Report CSD-TR 92-028
writen by Eugene H.
You can obtain this article from:
It has very nice description of Bloom filter and it's advantages for password
In simple words, apgbfm
hash values for every word and
sets corresponding bits in filter file to 1. To check the word apgbfm
generates the same hash functions for that word and if all n
corresponding bits in filter file are set to 1 then it suppose that word
exists in dicionary. apgbfm
as a hash function.
can be used as standalone utility, not only with apg
- WARNING !!!
- Filter file format can be changed in the future. I'll try
to make file formats compatible but i can not guaranty this.
- WARNING !!!
- apgbfm may slow down your computer during filter
- -f filter
- use filter as the name for Bloom filter
- -i filter
- print information about filter.
- -n numofwords
- create new empty filter for numofwords number of
words. Useful when you want to fill filter dynamicaly.
- -d dictfile
- create new filter from dictfile. It may take a lot
of time to generate filter from a big dictionary. In that dictionary you
may place words (one per line) that should not appear as generated
passwords. For example: user names common words, etc. You even can use one
of the dictionaries that come with dictionary password crackers.
This check is case sensitive. For example, if you want to reject word
'root', you should insert in dictfile words: root, Root, RoOt, ...
, ROOT. To indicate that program is working apgbfm prints dot for
every 100 words added in dictionary.
- -a word
- add word to the filter.
- -A dictfile
- add all words from dictfile to the filter. To
indicate that program is working apgbfm prints dot for every 100
words added in dictionary.
- -c word
- check word for appearance in the filter.
- -C dictfile
- check every word from dictfile for appearance in the
- quiet mode.
- create new filter in case-insensitive mode.
- print version information.
- print help information.
On successful completion of its task, apgbfm
will complete with exit code
0. An exit code of -1 indicates an error occurred. Textual errors are written
to the standard error stream.
If you've found one, please send bug description to the author.
This man page is Alpha too.
Adel I. Mirzazhanov, <email@example.com>
Project home page: http://www.adel.nursat.kz/apg/