Masterkeying question
Ralph A. Schmid, dk5ras
at the moment I am examining a 30 year old masterkey system.
It is a 5 pin RC (the number of cuts common between GMK and change key
bittings varies betwenn 1 and 2) system, 1 GMK, 2 MKs, about 70 change
keys.
My first question is, all keys are cut identical in cut # 5, at the
tip. Is there a specific (mechanical?) reason to have this common
pinstack in postion # 5, or could it also be any other place?
Second question, although these are high quality locks of tight
tolerances, capable of many (10+) depths, in each position only four
depths are used, in 1mm steps. Why? Because of the size of the
additional "mastering" pins between plug and shell pins which is 1mm?
-ras
--
Ralph A. Schmid
http://www.dk5ras.de/ http://www.db0fue.de/
http://www.bclog.de/
harkawy
Without knowing the manufacturer of the locks that you are referring
to, it makes it a little more difficult to answer your questions, but
in generalities....
Answer for question 1: Does "RC" stand for "Removable Core" or
"Russwin/Corbin" (a lock manufacture.) If the cut in the fifth
position of each of the change keys is the same cut as that of the
GMK, then the design of the system could be "Rotating Constants" which
is one of three methods of master keying. That chamber will stay the
say until all the other chambers have progressed and then the fourth
chamber will match the GMK and all the other chambers will progress.
Answer for question 2: The master key system was set up as a two step
system. Depths 0 through 9 or 1 through 10: One depth for the GMK
and then four depths for the change keys. In a five pin Rotating
Constant system where one chamber is used for the MK's, there is the
potential of 256 change keys for each MK... M R1 R2 R3 R4..... Where
one R is the same as the GMK so (R1(4) * R2(4) * R3(4) = 64), plus (R1
* R2 * R4 = 64) plus (R1 * R3 * R4 = 64) plus (R2 * R3 * R4 = 64.)
There are 4 sets of 64 or 256 change keys.
I hope this helps. If not, then may I suggest that you take a class
on master keying.
On Aug 29, 9:33 am, "Ralph A. Schmid, dk5ras" <ra...@radio-link.net>
wrote:
peterwn
RC refers to 'rotating constant' meaning that change keys share an
equal number of cuts with the master key. More differs are available
in a one level MK system if one cut is a rotating constant.
Having the last pin 'constant' seems a designer's preference but could
have the following benefits:
1. possible less chance of opening another cylinder in the suite by
wriggling a key to and fro. Even better tail of key slopes up to a
'flat' then slopes up again.
2. a maison cylinder would be slightly more secure if there is no
spacer in the last position especially that some pin stacks are often
omitted from maison cylinders.
3. if each of the ten levels of the last pin is used for a different
suite within a town or district, there is assurance that a key from
one suite will not act as an incidential masterkey (which shares cuts
between the masterkey and some change keys) in another suite.
What I cannot understand is the use of one or two constant cuts. This
only makes sense if there was some special key such as an
'engineering' key intended to fit doors which maintenance people need
to access.
Ralph A. Schmid, dk5ras
>Ralph,
>Answer for question 1: Does "RC" stand for "Removable Core" or
>"Russwin/Corbin" (a lock manufacture.) If the cut in the fifth
RC means a Rotating Constants keying scheme. It is a German make,
manufacturer is Zeiss Ikon, and it seems as a variant of a RC scheme.
>I hope this helps. If not, then may I suggest that you take a class
>on master keying.
The principles of masterkeying so far are clear - just thought there
are some things I had missed :)
-ras
--
Ralph A. Schmid
http://www.dk5ras.de/ http://www.db0fue.de/
http://www.bclog.de/
harkawy
wrote:
I completely understand. Sometimes I can't see the forest for the
trees. But I have an excuse.... I'm older than dirt.
peterwn
wrote:
> harkawy <hark...@rabbitsoft.us> wrote:
> >Ralph,
> >Answer for question 1: Does "RC" stand for "Removable Core" or
> >"Russwin/Corbin" (a lock manufacture.) If the cut in the fifth
>
> RC means a Rotating Constants keying scheme. It is a German make,
> manufacturer is Zeiss Ikon, and it seems as a variant of a RC scheme.
>
> >I hope this helps. If not, then may I suggest that you take a class
> >on master keying.
>
> The principles of masterkeying so far are clear - just thought there
> are some things I had missed :)
>
> -ras
>
But then it would seem there are many different ideas on how to
actually do masterkeying which would have their advantages and
disadvantages. One can design a 'perfect' system by the numbers and
yet the system may not hold up in practice. For example if an
incidental masterkey 00044 fits a cylinder the drivers may catch the
edges of the holes in the plug leaving the plug slightly turned as the
tip of the key (the reguar masterkey and/or change key) leaves the
plug.
One idea for a system using worn cylinders is master 99945, change
keys progress 00045, 00345, 00645 through to 66645. Maison cylinder
xxx45 (x means no pin stacks). 27 differs available as long MACS is
at least 6 or 26 if the maison cylinder needs its own change key.
Ralph A. Schmid, dk5ras
>But then it would seem there are many different ideas on how to
>actually do masterkeying which would have their advantages and
At the moment (as I have completed noting down all change keys
bittings) it seems to me that it is not a pure RC scheme, and the
rotation of the bittings does not correspond to the stamped serial
numbers, to make it more difficult to reverse engineer it, I guess.
>disadvantages. One can design a 'perfect' system by the numbers and
>yet the system may not hold up in practice. For example if an
>incidental masterkey 00044 fits a cylinder the drivers may catch the
>edges of the holes in the plug leaving the plug slightly turned as the
>tip of the key (the reguar masterkey and/or change key) leaves the
>plug.
>
>One idea for a system using worn cylinders is master 99945, change
>keys progress 00045, 00345, 00645 through to 66645. Maison cylinder
>xxx45 (x means no pin stacks). 27 differs available as long MACS is
>at least 6 or 26 if the maison cylinder needs its own change key.
Here in Germany with normal pin tumbler locks (five to seven stacks)
it is a cler no-go to leave chambers unpinned. So the maison cylinders
usually has up to five shear lines. Anyway, both methods lead to a
lock that can be opened with two paper clips :) Usually not a problem
for an apartment building, but for industrial buidlings a major risk
when the protection of the external shell is done with the weakest
locks of the system, while unimpiortant rooms where only few people
need access (liek storage for cleaning agents) get the locks with
tightest security (few shear lines).
peterwn
wrote:
> Here in Germany with normal pin tumbler locks (five to seven stacks)
> it is a cler no-go to leave chambers unpinned. So the maison cylinders
> usually has up to five shear lines. Anyway, both methods lead to a
> lock that can be opened with two paper clips :) Usually not a problem
> for an apartment building, but for industrial buidlings a major risk
> when the protection of the external shell is done with the weakest
> locks of the system, while unimpiortant rooms where only few people
> need access (liek storage for cleaning agents) get the locks with
> tightest security (few shear lines).
>
A dean asked me when I was young how many levels of masterkeying was
possible and I said three or four after which security would suffer. I
think he was wanting to know about maison keying. His new building
had maison keying so the professors could enter the building and the
library with their office keys.
I happened to meet a locksmith in the firm who imported the system and
I cynically said that there would be empty pin stacks. He said no, and
the manufacturer used multiplex keyways to get enough maison differs
without putting too many spacers in the maison cylinders. I noticed
after a decade or so completely different cylinders had been put on
the external doors (they probably now have swipe cards).
It seems Kaba has the best maison system since as far as I know they
have two types of cylinder with the pins placed differently so one set
of dimples on the key works the regular cylinder and another set the
maison cylinder.
peterwn
wrote:
The example I cited was in a tips & tricks booklet published by some
USA locksmithing group. It would have been quite feasible to use 3
spacers in the first three chambers since they would have been 3 level
spacers and not cause trouble on worn cylinders. In conjunction with
using 99927 for the masterkey the maison cylinder would not yield to a
paperclip etc.
Bramah omitted sliders in his original masterkeyed locks. That would
habe been OK as the masterkeyed cylinder was designed for 8 sliders
with 6 used (I think his regular locks used 6 anyway). This gave 28
differs under a masterkey which was ample since only a small number of
Bramah locks would have been used in any palace, stately home etc.
Ralph A. Schmid, dk5ras
>In conjunction with
>using 99927 for the masterkey the maison cylinder would not yield to a
>paperclip etc.
BUt usually those locks are easy to rake or pick...
peterwn
wrote:
> peterwn <pete...@paradise.net.nz> wrote:
> >In conjunction with
> >using 99927 for the masterkey the maison cylinder would not yield to a
> >paperclip etc.
>
> BUt usually those locks are easy to rake or pick...
>
Which is a reason not to use maison cylinders unless there are at
least five operable pin stacks with no more than say 6 spacers total
or 6 operable stacks with say no more than 10 spacers. Depending on
usage it should be replaced every year or two.
Judging by some previous postings, savvy building managers put a
restricted keyway cylinder on the main entrance, issue each apartment
with two keys and charge $80 or so each for replacement or extra keys.
People come squarking to this ng asking how they can get extra keys
made without going via the building manager. Presumably after 3-4
years there is enough money in the kitty for a re-key.
Ralph A. Schmid, dk5ras
>Which is a reason not to use maison cylinders unless there are at
>least five operable pin stacks with no more than say 6 spacers total
>or 6 operable stacks with say no more than 10 spacers. Depending on
>usage it should be replaced every year or two.
Yes, sounds like a good idea.
>Judging by some previous postings, savvy building managers put a
>restricted keyway cylinder on the main entrance, issue each apartment
>with two keys and charge $80 or so each for replacement or extra keys.
>People come squarking to this ng asking how they can get extra keys
>made without going via the building manager. Presumably after 3-4
>years there is enough money in the kitty for a re-key.
This is in Germany not so common; when there is a MK system usually
all locks are involved. But often enough the residents anyway change
the door lock, to avoid unauthorised access, and/or to have more keys
at hand (at reasonable cost) than the usual three ones.
peterwn
wrote:
In USA masterkeying of apartment buildings is generally mandatory to
allow rapid Fire Department access. Hence tenants are forbidden from
changing locks. This does not seem to appy in Europe, UK, 'down
under' etc. Where I come from, deaths of solitary people in council
apartments is a problem as they were sometimes not discovered until
several weeks later, there being often no friends or relatives in
close contact to raise the alarm. There was a suggestion thet
apartments be masterkeyed so caretakers could check but this came to
nothing presumably because of resistance from tenants (who are highly
suspicious of council management).
Ralph A. Schmid, dk5ras
>In USA masterkeying of apartment buildings is generally mandatory to
>allow rapid Fire Department access. Hence tenants are forbidden from
>changing locks. This does not seem to appy in Europe, UK, 'down
>under' etc. Where I come from, deaths of solitary people in council
>apartments is a problem as they were sometimes not discovered until
>several weeks later, there being often no friends or relatives in
>close contact to raise the alarm. There was a suggestion thet
>apartments be masterkeyed so caretakers could check but this came to
>nothing presumably because of resistance from tenants (who are highly
>suspicious of council management).
Here in case of emergency just forceful entry is done, and that is it.
What does a MK help when nobody is around to deliver it in time?
Evan
wrote:
> peterwn <pete...@paradise.net.nz> wrote:
> >In USA masterkeying of apartment buildings is generally mandatory to
> >allow rapid Fire Department access. Hence tenants are forbidden from
> >changing locks. This does not seem to appy in Europe, UK, 'down
> >under' etc. Where I come from, deaths of solitary people in council
> >apartments is a problem as they were sometimes not discovered until
> >several weeks later, there being often no friends or relatives in
> >close contact to raise the alarm. There was a suggestion thet
> >apartments be masterkeyed so caretakers could check but this came to
> >nothing presumably because of resistance from tenants (who are highly
> >suspicious of council management).
>
> Here in case of emergency just forceful entry is done, and that is it.
> What does a MK help when nobody is around to deliver it in time?
>
> -ras
Ralph:
No one has to "deliver" those apartment MK's to the fire department
because they are secured in Knox Rapid Entry (or equivalent)
key vaults installed on the premises near the main entry doors which
only the fire department has access to as required by the AHJ...
If for some reason those keys do not operate a lock on a door which
needs to be accessed, then such a door gets broken down when
entry is required... It is much safer for everyone involved for a key
to be used in accessing a door, it is quicker and depending on the
level of security upgrades made to the door -- it does far less damage
given the invasive emergency ingress methods and tools that the
fire department uses which would leave most doors unrepairable
after a forced entry has been made...
In the event a tenant changes a lock in such an apartment complex
and forced entry is required, the tenant is usually personally
responsible for the costs of the required repairs in a stipulation of
the lease agreement that they signed...
Evan,
~~ formerly a maintenance man, now a college student...
Ralph A. Schmid, dk5ras
>Ralph:
>
>No one has to "deliver" those apartment MK's to the fire department
>because they are secured in Knox Rapid Entry (or equivalent)
>key vaults installed on the premises near the main entry doors which
>only the fire department has access to as required by the AHJ...
We have something similar here for commercial buildings. Fire alarm
unlocks the box, only then the fire brigade can open the box with
their own key.
>In the event a tenant changes a lock in such an apartment complex
>and forced entry is required, the tenant is usually personally
>responsible for the costs of the required repairs in a stipulation of
>the lease agreement that they signed...
Here not. The problem is, a MK system allows that any other tenant is
able to make a MK from reverse engineering the lock, not to mention
the lack of control who owns a legit MK and what it is used for. This
does not comply with the constitutional rights here regarding privacy
of ones place. There is even no discussion about that, it is
absolutely clear that you have the right to control who has access to
your place, and who not.
>Evan,
peterwn
It would seem that something like card operated hotel room locks (but
without over-ride cylinders) or Cyberlock cylinders (
www.videx.com/CyberLock/CyberLock.html ) would be a good option for
apartments. The tenant or 'owner' would however need to have some
ready means of listing the lock audit. This would be a hefty
deterrent to the super or staff snooping in apartments. And of course
a lost masterkey or card can be almost immediately disabled (someone
would need to re-program each cylinder, but that should only require
insertion of a specially programed key or card into each lock).
Evan
>
> It would seem that something like card operated hotel room locks (but
> apartments. The tenant or 'owner' would however need to have some
> ready means of listing the lock audit. This would be a hefty
> deterrent to the super or staff snooping in apartments. And of course
> a lost masterkey or card can be almost immediately disabled (someone
> would need to re-program each cylinder, but that should only require
> insertion of a specially programed key or card into each lock).
That all depends on what the AHJ approves for access to the
apartments... Those fancy electronic locks sound like a great
option, yet they require A LOT of maintenance to operate 100%
at all times...
Best makes lock sets which can be used as standalone devices
which can be easily organized and programmed using a PDA or
laptop without requiring large investment in special proprietary
tools...
The funny thing about those mag stripe locks is that they get really
dirty especially when used outside...
It is my experience with standalone electronic products that unless
they are used in some business application where performing audits
is required that they are seldom done until something actually
happens...
The biggest difference between what Ralph was describing as an
"apartment" in Europe and what is considered an "apartment" in the
US is who has ownership of the property... Very few "apartment"
dwellers here in the US have ownership rights over the property they
occupy... Hence much greater restrictions can be placed on tenants
as to whose locks and which type of locks can be used to secure the
rented premises...
Ralph A. Schmid, dk5ras
>The biggest difference between what Ralph was describing as an
>"apartment" in Europe and what is considered an "apartment" in the
>US is who has ownership of the property... Very few "apartment"
>dwellers here in the US have ownership rights over the property they
>occupy...
Here in Germany there is no difference whether you buy or rent the
place. In any case you can place there your own lock, and even when
the contract forbids it, this paragraph would not stand a lawsuit. Our
constitution says, "Die Wohnung ist unverletztlich", means, "The home
is inviolable". These few words make it very clear, and the few
exceptions are search warrants, immediate danger and such. For those
exceptional cases it is not demanded to deposit a key somewhere or
allow a masterkey.
Ownership has here nothing to do with any right to enter a place. We
have in Germany two words, "Besitz" und "Eigentum". They translate
similar into English, and I do not know exactly how this can be
distinguished. Maybe the law terms are "seizin" vs. "ownership"; at
least these are mentioned as law terms in a dictionary. "Besitz"
means, you have it right now at hand for your use, not distinguishing
if you did buy, rent or steal it, "Eigentum" means, that you really
own it. So actually you even can occupy a place without having the
right to do so, and the whole law machinery (eviction order!) must
cranked up to get you out of it. A PITA for an owner when the tenant
just stops paying the rent. It can take months to get him out...
Sounds like nitpicking, but necessary to protect the tenant, and
although not widely known, we Germans also hold high our
constitutional rights :-)
This is very interesting stuff; in the US you have the right to own
and in some places even carry firearms, and this right is strongly
defended - but you are not allowed to remove the MKed lock from your
flat.
Evan
wrote:
Correct, as when you rent a property, you are not owning it and
therefore lack legal rights to make certain decisions about how
it works and what is it equipped with... When you own something
you have full legal rights to make changes...
As to your firearms comment, that right is not as absolute as it
sounds, as it can be restricted in many ways and often relies on
some bureaucrat making the approval decision on your application
for a firearms license...
As far as "occupying a place without the right to do so" it sounds
as if German law is backwards... Here in the US if you squat in
such a way, you had better hope someone merely left the door
open for you to enter -- that would be trespassing... If you had
to break anything when you gained your unauthorized entry to
the unit you have no legal right to occupy that can be considered
"breaking and entering" which is a felony in every state... Often
if you do this at night under the cover of darkness (since people
might be watching during the day for intruders) it makes such
an offense even more serious (longer prison sentence if you are
caught and brought to trial)... In the parts of the US I am familiar
with someone who is occupying a place without the legal right
to do so is not subject to the eviction process, which only
applies to lawful tenants whom have legal rights to occupancy
which need to be protected by the due process of eviction
proceedings...
Ralph A. Schmid, dk5ras
>As to your firearms comment, that right is not as absolute as it
>sounds, as it can be restricted in many ways and often relies on
>some bureaucrat making the approval decision on your application
>for a firearms license...
I know this; just one example.
>As far as "occupying a place without the right to do so" it sounds
>as if German law is backwards... Here in the US if you squat in
No, it just protects the citizens, to prevent a landlord (who is
usually in a stronger position than a tenant) from throwing people out
for some made up reason. It is not possible to order a tenant to leave
right now because this is a very desperate situation. So there are
deadlines, and procedures have to be followed, as ist has to be in a
civilized society.
>such a way, you had better hope someone merely left the door
>open for you to enter -- that would be trespassing... If you had
>to break anything when you gained your unauthorized entry to
>the unit you have no legal right to occupy that can be considered
>"breaking and entering" which is a felony in every state... Often
Here also - the problem is not breaking in, of course similar measures
are taken when this is obvious. You even can shoot the guy and get
away with it, when he threats you.
>if you do this at night under the cover of darkness (since people
>might be watching during the day for intruders) it makes such
>an offense even more serious (longer prison sentence if you are
>caught and brought to trial)... In the parts of the US I am familiar
>with someone who is occupying a place without the legal right
>to do so is not subject to the eviction process, which only
>applies to lawful tenants whom have legal rights to occupancy
>which need to be protected by the due process of eviction
>proceedings...
It is a difference if there is a masked guy, trying to steal
something, or if there is someone with all his belongings, living
there and claiming that he has the right do to so.
-ras
--
Ralph A. Schmid
http://www.dk5ras.de/ http://www.db0fue.de/
http://www.bclog.de/
peterwn
Evan, perhaps you could clarify things. Am I right in thinking that:
Apartment - landlord ownd building and rents out each dwelling.
Condominium - Each dwelling owner has a title to that dwelling and
there is a corporate body or similar to attend to communal features
such as elevators, fire alarms etc. Each owner can live in the
dwelling or rent it out.
Co-op - Company or similar owns building and there is a parcel of
shares associated with each dwelling. Buying a dwelling involves
buying the associated shares and the Board / Committee can veto a
transfer - Manhattan co-ops being notorious for this. Presumably co-
op's can exercise more control over use of dwellings than with
condominiums.
With an apartment, the landlord can obviously dictate what locks are
used on individual dwellings.
I had thought after reading this ng that the Fire Department required
masterkeyed locks and this would also apply to condominiums and co-
op's..
It seems there are exceptions. A woman (may be the 'Pamela Jones' of
Groklaw) had a Medeco on her rather down-market apartment, and
presumably must have got dispensation. It frustrated a private
detective trying to get the goods on her, and he presumably had to
bribe the super (presumably now ex-super) to have a peep inside. There
was an internet article describing this and her fans thought she
'rocked' for having the foresight to install a Medeco lock. The
detective did not find anything significant. She is a paralegal and
knew that law offices needed Medeco or similar to prevent 'without
trace' breakins.