Re: Master Key crack
From: John E. Hadstate (nospam_at_null.nil)
Date: 07/29/03
- Next message: Paul Rubin: "Re: Is RC4 a good choice?"
- Previous message: Richard Heathfield: "Re: Generic Question [rump sessions]"
- In reply to: Richard Herring: "Re: Master Key crack"
- Next in thread: Richard Herring: "Re: Master Key crack"
- Reply: Richard Herring: "Re: Master Key crack"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]
Date: Tue, 29 Jul 2003 15:08:55 -0400
"Richard Herring" <junk@[127.0.0.1]> wrote in message
news:KO4eUTtVapJ$EwcG@baesystems.com...
> In message <3f2677e9$1_2@news.vic.com>, John E. Hadstate
> <nospam@null.nil> writes
> >
> >"Stuart Green" <greens80@hotmail.com> wrote in message
> >news:1761049f.0307290239.28dd7f11@posting.google.com...
> >> I remeber reading an article about a guy who utilised a master key
> >> hack, known to locksmiths, to identify pin placements on a key and
> >> grind them down progressively to build a masterkey for a lock.
>
> [...]
>
> >In a simple system producing one Master and one Owner key for each lock,
> >each pin position in the lock has two short pins inserted. The length of
> >the first pins in each pin position establish the cut heights for the
Owner
> >keys. The sum of the lengths of the first and second pins in each
position
> >establish the cut heights for the Master key. The pins come in standard
> >lengths, and there are constraints on the maximum height differences
between
> >adjacent pins. Typical locks come with 4, 5, or 6 pin positions.
> >
> >There are a finite number of combinations of pins that make up each
Master
> >series. Thus, one might enumerate all the possible pin placements for
owner
> >keys for each Master series. Then, given a few owner keys known to be
part
> >of one Master series, one might search the entire tree of pin
combinations
> >until one established which Master series included all the given owner
keys.
> >This would establish the cut lengths for the Master key for that series.
> >
> >I suspect that for any decent system, you would need a lot more than 4
owner
> >keys to establish which Master series they belong to (although there are
> >some Master series for 4-pin tumblers that produce a very small number of
> >usable owner keys).
> >
> I think the "master key hack" mentioned by the OP is the one where one
> sequentially varies the height of a single pin on one known Owner key to
> determine the Master height at that pin. In principle, given one Owner
> key and access to the keyhole, that will yield the complete Master
> heights using as many blanks as there are pin positions, plus a lot of
> filing.
>
> --
> Richard Herring
s
s
s
s
gggpggggg
p
1
1
1
2
2
k
k
k
To make this Owner key work, "k" has to push p up by 1 unit (so it aligns
with "g").
To make the Master key work, "k" has to push p up by 4 units (so the lowest
"1" aligns with "g").
Thus, the Owner key has to be cut more deeply at each pin position than the
Master key.
So, other than showing a maximum cutting depth for each pin position, how
does the Owner key reveal the Master key?
- Next message: Paul Rubin: "Re: Is RC4 a good choice?"
- Previous message: Richard Heathfield: "Re: Generic Question [rump sessions]"
- In reply to: Richard Herring: "Re: Master Key crack"
- Next in thread: Richard Herring: "Re: Master Key crack"
- Reply: Richard Herring: "Re: Master Key crack"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]
Relevant Pages
|
|
