ray@philmtl.philips.ca (Ray Dunn) (02/13/90)
I have a need to provide a password mechanism in a particular situation,
but, for various boring reasons, have only got a couple of spare bytes in
which to store it.
My first approach would be to compute a CRC on the password, and only store
that.
Can someone point me to the best source of ideas on this subject,
particularly on how to compute the number of different passwords, say 8
characters long, which will match a given CRC value computed by various
algorithms?
Anyone have any other bright ideas? Please accept the lack of space to
store the full password as a given.
If you email me your response I will summarize back to this newsgroup.
Thanks in advance for your assistance.
--
Ray Dunn. | UUCP: ray@philmtl.philips.ca
Philips Electronics Ltd. | ..!{uunet|philapd|philabs}!philmtl!ray
600 Dr Frederik Philips Blvd | TEL : (514) 744-8200 Ext : 2347 (Phonemail)
St Laurent. Quebec. H4M 2S9 | FAX : (514) 744-6455 TLX : 05-824090crobw@acad.cut.oz (02/21/90)
In article <1231@nixpbe.UUCP>, mollers.pad@nixpbe.uucp (Moellers) writes: >[...] > There used to be an algorithm on the PDP-11 which packed 3 characters in > 2 bytes. The characterset was restricted to UC and digits -> 36 > different chars, > max. value (35*36+35)*36+35 == 46655 > The method was called RADIX50, from 50 (base 8), or 40 (base 10), so that another 4 special characters can be included. Specifically 6 characters from the set of 40 can fit into 32 bits thus:- ((((C6*40+C5)*40+C4)*40+C3)*40+C2)*40+C1, where 0.le.Cj.le.39 (base 10) 40^6 = 4096*10^6 = F4240000 (hex) _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- Rob Wright | psi%050529452300030::CROBW Curtin University | CROBW%acad.curtin.edu.au@uunet.uu.net Perth, Western Australia | CROBW%acad.curtin.edu.au%munnari.oz@cunyvm.bitnet Voice:+61 9 351 7385 | munnari!acad.curtin.edu.au!CROBW@uk.ac.ukc FAX: 09-351-2673 | {backbones}!munnari!acad.curtin.edu.au!CROBW -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_