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APGBFM(1)			  User Manual			     APGBFM(1)

       apgbfm -	APG Bloom filter management program

       apgbfm -f filter	-n numofwords [-q] [-s]
       apgbfm -f filter	-d dictfile [-q] [-s]
       apgbfm -f filter	-a word	[-q]
       apgbfm -f filter	-A dictfile [-q]
       apgbfm -f filter	-c word	[-q]
       apgbfm -f filter	-C dictfile [-q]
       apgbfm -i filter
       apgbfm [-v] [-h]

       apgbfm is used to manage	Bloom filter that is used to restrict password
       generation in APG pasword generation software. Usage of the Bloom  fil-
       ter  allows  to	speed up password check	for large dictionaries and has
       some other benefits.

       The idea	to use Bloom filter for	that purpose is	came from the descrip-
       tion  of	the OPUS project OPUS: Preventing Weak Password	Choices	Purdue
       Technical Report	CSD-TR 92-028 writen by	Eugene H. Spafford.

       You can obtain this article from:
       It has very nice	description of Bloom filter and	 it's  advantages  for
       password	checking systems.

       In simple words,	apgbfm generates n hash	values for every word and sets
       corresponding bits in filter file to 1. To check	the word apgbfm	gener-
       ates  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 uses SHA-1 as	a hash function.

       apgbfm can be used as standalone	utility, not only with apg, or apgd.

       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 creation.

       -f filter
	      use filter as the	name for Bloom filter filename.

       -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	gener-
	      ated 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 dic-

       -a word
	      add word to the filter.

       -A dictfile
	      add all words from dictfile to the filter. To indicate that pro-
	      gram  is	working	apgbfm prints dot for every 100	words added in

       -c word
	      check word for appearance	in the filter.

       -C dictfile
	      check every word from dictfile for appearance in the filter.

       -q     quiet mode.

       -s     create new filter	in case-insensitive mode.

       -v     print version information.

       -h     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 er-
       rors are	written	to the standard	error stream.


       None.  If you've	found one, please send bug description to the author.

       This man	page is	Alpha too.

       apgd(8),	apg(1)

       Adel I. Mirzazhanov, <>
       Project home page:

Automated Password Generator	  2003 Jun 19			     APGBFM(1)


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