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 password generation software. Usage of the Bloom filter allows one 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 description of the OPUS project OPUS: Preventing Weak Password Choices Purdue Technical Report CSD-TR 92-028 written by Eugene H. Spafford.
You can obtain this article from:
http://www.cerias.purdue.edu/homes/spaf/tech-reps/9128.ps
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 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 uses SHA-1 as a hash function.
apgbfm can be used as standalone utility, not only with apg, or apgd.
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.
None.
None. If you've found one, please send bug description to the author.
This man page is Alpha too.
apg(1)
Adel I. Mirzazhanov, <a-del@iname.com>
Project home page: http://www.adel.nursat.kz/apg/
2003 Jun 19 | Automated Password Generator |