Master Key Systems

[Shangri-laschild]

I have learned some basic stuff about master key systems and I know how to repin locks. Currently I'm working with a master keyed system that has 4 levels (GGM, GMK, MKA, KA1). I'm not sure if I'm missing something and my brain is just stuck or something but I had a couple of questions.

What makes certain locks cross keyed. I know how to pin a cross keyed lock, and what it means as far as what keys can open it. I mean, when you are creating a system, how do you know which are able to be cross keyed?

I have the general idea that you're not supposed to just pin a lock to whatever and that in theory you should keep it within the system. For instance, KA1 can be opened by the keys KA1, KA2, and KA3 but I pin it so that KB3 can open it. I'm not sure if I'm thinking of this wrong and it's fine or not. I figure that if you could do it, there would be no need for certain locks to be specified as cross keyed. For instance, when I was looking in to creating new locks under a submaster (for instance, KA4) I was told that it would not be able to be fit under the KA1 cross keyed lock. I know it couldn't be done automatically and that it would take repinning the KA1 locks if it was possible, but I guess I'm curious why it's not possible and why you can't do things like that with key systems?

Are there any things that I need to worry about when adding new keys/locks to a key system?

[globallockytoo]

cross keying is also sometimes referred to as "phantom" or "ghost" keying, where a phantom or ghost key can be created to work in a number of cylinders.

Generally speaking, you cannot program for a phantom (ghost/cross) key. You can maison key, specific cylinders to accept all or a range of keys in the system.

Phantom (ghost/cross) keys are unknown by nature, but mathematically a computer program can tell you where cross keying will occur.

Systems like Promaster, will not let you create the pinning chart until all phantoms are removed or deliberately made to work those cylinders.

[jdislandlock]

i was under the impression cross key meant having a key that should not work, accidentally will work the lock...

meaning there is something wrong with the math/cut on keys....


There is master key wich opens everything,.... 2 units
then there is the Change key which would be for say the tenant...? 1 unit which would be different for each unit

[jdislandlock]

Systems like Promaster, will not let you create the pinning chart until all phantoms are removed or deliberately made to work those cylinders.

we use masterking , it eliminates all cross keys while in the process of making system.

Excellent program, simple and fast.

[Eyes_Only]

Is that the one from HPC?

[Shangri-laschild]

cross keying is also sometimes referred to as "phantom" or "ghost" keying, where a phantom or ghost key can be created to work in a number of cylinders.

Generally speaking, you cannot program for a phantom (ghost/cross) key. You can maison key, specific cylinders to accept all or a range of keys in the system.

Phantom (ghost/cross) keys are unknown by nature, but mathematically a computer program can tell you where cross keying will occur.

Systems like Promaster, will not let you create the pinning chart until all phantoms are removed or deliberately made to work those cylinders.

By phantom vs programed in, do you mean sort of like how if I have a door key that is 55555 and another that is 22222 and I key it to both, technically any combination of those two numbers will open it? The way our system is set up, lets say you have KA1X, KA2, and KA3, with MKA, GMK, and GGM above it. Now if I'm pinning a lock for KA2, the numbers are such that I really only have to use GGM and KA2 in the math because those numbers cover the two in the middle. However, if I'm pinning a lock for KA1X, I have to use GGM, KA1X, KA2, and KA3 for the math because all of them are needed. The system is one that Corbin set up for us, so beyond that I don't have any information on it's creation. I'm not sure if the way the cross keyed locks are set up with out system is odd or not. I guess in my mind I was figuring that when I pinned the lock for GGM and KA1X, it would cover KA2 and KA3 like it does with GMK and MKA. Maybe I'm wrong about that?

As far as maison keying, is there any disadvantage to doing that? I guess I'm basically trying to fill in the blanks on what I understand about master keying. I work at a college so we have a lot of departments where it's useful for the front door to be a cross keyed lock for the rest of the department locks. People don't like having to carry around lots of keys here no matter what the logic, so it's either set up cross keyed stuff of have to give them keys to way more than they need access to sometimes.

[globallockytoo]

cross keying is also sometimes referred to as "phantom" or "ghost" keying, where a phantom or ghost key can be created to work in a number of cylinders.

Generally speaking, you cannot program for a phantom (ghost/cross) key. You can maison key, specific cylinders to accept all or a range of keys in the system.

Phantom (ghost/cross) keys are unknown by nature, but mathematically a computer program can tell you where cross keying will occur.

Systems like Promaster, will not let you create the pinning chart until all phantoms are removed or deliberately made to work those cylinders.

By phantom vs programed in, do you mean sort of like how if I have a door key that is 55555 and another that is 22222 and I key it to both, technically any combination of those two numbers will open it? Correct

The way our system is set up, lets say you have KA1X, KA2, and KA3, with MKA, GMK, and GGM above it. Now if I'm pinning a lock for KA2, the numbers are such that I really only have to use GGM and KA2 in the math because those numbers cover the two in the middle. If that is how the system is designed then, yes.

However, if I'm pinning a lock for KA1X, I have to use GGM, KA1X, KA2, and KA3 for the math because all of them are needed. Essentially, you are creating KA1X as the phantom.

The system is one that Corbin set up for us, so beyond that I don't have any information on it's creation. If you have access to all the keys in the system, you can decode them all and store them locally, but doing so and then altering anything in the system will screw up the factory system if you dont inform the factory of any changes.

I'm not sure if the way the cross keyed locks are set up with out system is odd or not. I guess in my mind I was figuring that when I pinned the lock for GGM and KA1X, it would cover KA2 and KA3 like it does with GMK and MKA. Maybe I'm wrong about that? In my opinion, you should purchase a masterkeying software program to enable accurate records to be maintained, then cross keying can be factored in when creating new change keys or rekeying cylinders.

As far as maison keying, is there any disadvantage to doing that? The only disadvantage of maison keying is the possibility for any key in the system to potentially work a cylinder it is not supposed to. But maison keying is essentially what you are trying to do by (what you call) cross keying.

I guess I'm basically trying to fill in the blanks on what I understand about master keying. I work at a college so we have a lot of departments where it's useful for the front door to be a cross keyed lock for the rest of the department locks. People don't like having to carry around lots of keys here no matter what the logic, so it's either set up cross keyed stuff of have to give them keys to way more than they need access to sometimes.

I have set up and installed many GGGMK systems for schools, universities with one or multiple campuses. Often, maison keying is requested to minimise the quantity of keys being carried.

When I set up a system, I ask for the names of all key holders and list them from top to bottom. Then I number and name each and every door (across the top of a graph page) and check mark which key holder is allowed to access what door. I can then produce an individual key (that may be different from each other) for each person and load the appropriate cylinder with that keying.

Most of my systems that involve multiple floors and campuses, I color code the keys to easily identify them. I have created sub master keys for cleaners/janitors, maintenance persons etc etc. Color coding is the simplest method for differentiating keys in a system.

[Evan]

I have set up and installed many GGGMK systems for schools, universities with one or multiple campuses. Often, maison keying is requested to minimise the quantity of keys being carried.

When I set up a system, I ask for the names of all key holders and list them from top to bottom. Then I number and name each and every door (across the top of a graph page) and check mark which key holder is allowed to access what door. I can then produce an individual key (that may be different from each other) for each person and load the appropriate cylinder with that keying.

Most of my systems that involve multiple floors and campuses, I color code the keys to easily identify them. I have created sub master keys for cleaners/janitors, maintenance persons etc etc. Color coding is the simplest method for differentiating keys in a system.

@globallockytoo:

Those "My Key" matrix type systems really really suck when someone eventually ends up losing their key and the lock(s) for "their doors" need to be rekeyed... It often involves having to rekey more doors than if you keyed the locks to the building layout and function rather than the people using them... Such systems also often require extensive "double pinning" requiring two or more master pins in a chamber in several chambers in many locks in the system...

~~ Evan

[Evan]

I have learned some basic stuff about master key systems and I know how to repin locks. Currently I'm working with a master keyed system that has 4 levels (GGM, GMK, MKA, KA1). I'm not sure if I'm missing something and my brain is just stuck or something but I had a couple of questions.

What makes certain locks cross keyed. I know how to pin a cross keyed lock, and what it means as far as what keys can open it. I mean, when you are creating a system, how do you know which are able to be cross keyed?

I have the general idea that you're not supposed to just pin a lock to whatever and that in theory you should keep it within the system. For instance, KA1 can be opened by the keys KA1, KA2, and KA3 but I pin it so that KB3 can open it. I'm not sure if I'm thinking of this wrong and it's fine or not. I figure that if you could do it, there would be no need for certain locks to be specified as cross keyed. For instance, when I was looking in to creating new locks under a submaster (for instance, KA4) I was told that it would not be able to be fit under the KA1 cross keyed lock. I know it couldn't be done automatically and that it would take repinning the KA1 locks if it was possible, but I guess I'm curious why it's not possible and why you can't do things like that with key systems?

Are there any things that I need to worry about when adding new keys/locks to a key system?

Hi Shangri-laschild:

You always ALWAYS specify cross keyed locks using a capital X in front of the key symbol that will only open that lock followed by the phrase "Operated by:" with a list of all key symbols that should operate that cylinder... Example: XAA-4, Operated by: AA-4, AA-3, AA-2, AA-1, MK AA, GMK A. That example is called "Controlled Cross Keying" wherein all keys that operate that lock are under the same master key... If the cylinder in question does not require its own unique key that only operates it and nothing else then use the symbol "X1X" for the first one with a list of keys which should operate it and "X2X" for the second, etc...

Now lets look at the example you gave... "KA1 can be opened by the keys KA1, KA2, and KA3 but I pin it so that KB3 can open it." So this is translated to: XKA-1, Operated by: KA-1, KA-2, KA-3, KB-3 (and therefore MK KB), MK KA, GMK K, GGM. This is an example of "Uncontrolled Cross Keying" and it is dangerous depending on the bittings used and how the change keys have been progressed... Since there are now at least 4 or more change keys (depending on which ones were selected for the key symbols above) pinned into this lock under TWO different master keys (MK KA which is intended and desired to operate and MK KB which is NOT intended and not desired to operate) which operate that XKA-1 cylinder... Unless the change key KB-3 is a change key that is NOT operated by the MK KB you have also keyed that master key into the cross keyed cylinder XKA-1... You can see how quickly this can spin out of control if you add any additional keys to this cylinder under even more different master keys... If you set up your system planning on the uncontrolled cross keying interaction in this cylinder in advance then it is not a problem and you would have just not used the other change keys under the KB master which would also operate the XKA-1 cylinder, but if you have NOT planned for it from the beginning and those change keys are already in use somewhere you have created unintended key interchange in your system...

In the above scenario, to prevent unintended cross keying in an existing system where I don't know of every single key being used, I personally would not pin the lock in the manner suggested and require the holder of key KB-3 to carry an additional change key that is under the KA master that operates only the XKA-1 lock, KA-1 perhaps if it is not being used to open another door to an office or something...

In order to add new locks and expand your system or rekey existing locks due to missing keys, you have to know and understand the logic behind how the change key combinations were progressed from the available theoretical change keys under each master key and how they were assigned to become key symbols in the system... Example keyset "KA-2" corresponds to the direct bitting code 134561 or whatever it really is... You need to know this as well as ALL change key symbols and bitting combinations in use so you do not accidentally REPEAT any of them in the system and create unintended key interchange...

Hope that this explanation helps...

~~ Evan

[Evan]

As far as maison keying, is there any disadvantage to doing that? The only disadvantage of maison keying is the possibility for any key in the system to potentially work a cylinder it is not supposed to. But maison keying is essentially what you are trying to do by (what you call) cross keying.

"Maison Keying" is the terminology used for a cylinder when EVERY key in the system will operate such a cylinder... It is commonly used in apartment and condo homes on the front door... While it is technically "cross keying" it is different than cross keying as being discussed in this thread...

~~ Evan

[Evan]

By phantom vs programed in, do you mean sort of like how if I have a door key that is 55555 and another that is 22222 and I key it to both, technically any combination of those two numbers will open it?

YES... Also key 77777 would operate as well as any key which combines 2, 5 or 7 bittings... Its a long list... Here is some of it:
22225, 22255, 22555, 25555, 22227, 22277, 22777, 27777,
55552, 55522, 55222, 52222, 55557, 55577, 55777, 57777,
77772, 77722, 77222, 72222, 77775, 77755, 77555, 75555,
and on and on until all combinations of 2, 5 and 7 in any position are exhausted...

The way our system is set up, lets say you have KA1X, KA2, and KA3, with MKA, GMK, and GGM above it. Now if I'm pinning a lock for KA2, the numbers are such that I really only have to use GGM and KA2 in the math because those numbers cover the two in the middle.

In general yes, selecting a given change key and the TMK to pin into a lock this will normally include all intermediate keys, but not always, this depends on how your system was designed and what type of locks you are using (single shear line cylinders vs. master ring cylinders) and whether or not your system has a special selective master key that should also operate e.g "ENG"...

However, if I'm pinning a lock for KA1X, I have to use GGM, KA1X, KA2, and KA3 for the math because all of them are needed.

You have to use the special pinning instructions for that XKA-1 cylinder... Each cross keyed lock in a properly designed master keying system will list "Operated by:" and a list of the key symbols to operate that cylinder... If you have a pinning chart for the system it will specify the pinning for each unique lock cylinder...

The system is one that Corbin set up for us, so beyond that I don't have any information on it's creation. I'm not sure if the way the cross keyed locks are set up with out system is odd or not. I guess in my mind I was figuring that when I pinned the lock for GGM and KA1X, it would cover KA2 and KA3 like it does with GMK and MKA. Maybe I'm wrong about that?

That sounds like a reasonable assumption... You best take care to make sure only the keys you want to operate said lock do and that you are not mistakenly using the additional combinations which also operate that lock accidentally elsewhere...

As far as maison keying, is there any disadvantage to doing that? I guess I'm basically trying to fill in the blanks on what I understand about master keying. I work at a college so we have a lot of departments where it's useful for the front door to be a cross keyed lock for the rest of the department locks. People don't like having to carry around lots of keys here no matter what the logic, so it's either set up cross keyed stuff of have to give them keys to way more than they need access to sometimes.

Well, this depends on the unique circumstances of your situation... It isn't really "maison keying" since not every key in the entire master keyed system operates the lock, it is really what is called "controlled cross keying"... Some disadvantages of extensive cross keying are: you will eventually end up with the lock cylinders being partially turned if someone with a declining step change key yanks their key out hard before returning it to the key pull position; you can also lose master pins from such locks and that results in some change and master keys no longer functioning; and, you will find that extensively cross keyed locks are more susceptible to being "key manipulated" by random keys from within the same master key system... Where someone with a key not intended to operate that cylinder "rakes" the lock with their key while turning, some keys will operate this lock if many many keys under different master keys operate such a lock...

Why would you need to cross key everything ? It seems perfectly reasonable to key a department entry lock (let's say it is the entry door to an area with 30 offices within it) to one or two keys and everyone inside that common entry door has to carry a separate key to it... Because you can quickly get pretty ridiculous when you start considering other things like: are there locked bathrooms inside this area ? Is their a file room, supply closet or storage room inside this area that only certain key holders should be able to access ?

Imagine trying to cross key all those locks to each other so that a key holder only needed one key to operate the common department entry door, the file room, the supply closet and the men's restroom and his personal office door but not anything else... Now imagine in two years when that professor is promoted to become a Dean and the person selected to replace him is female and should not be able to access the supply closet because of their junior status within the department... That creates massive headaches when you need to rekey that office door when selecting the proper keying code to use since you need to now key it to the common department entry door, the file room, the woman's restroom and that individual office door but not anything else... Not to mention the impact it has on the available change key bittings you can use under that master key -- most of them would be lost due to key interchange...

In such a situation I would consider the permutations of the common (shared) doors and cross key ONLY those doors with the common department entry door... (I.E. there is a file room, a supply room and a storage room in addition to the common department entry door...) How many possible combinations of access are there among those four doors that are different from each other... Creating the following keys is something to consider: file room only; supply room only; storage room only; file room, supply room and storage room; file room and supply room; file room and storage room; and, common department entry doors only... You now have only 8 different change keys that need to work within this group of locks... With 4 different change keys operating the file room, 3 different change keys operating the supply room, 3 different change keys operating the storage room and all 8 change keys operating the common department entry doors... This makes for much more secure cylinders compared to having every office door key operate the common department entry door also and MUCH MORE SECURE compared to the ridiculous cross keying example in the paragraph above this one...

You have FAR fewer keys to cross (only 8 compared to more than 30 intended change keys originally) into the locks involved and you are not losing as many available change key combinations being excluded under that master key to prevent unintended key interchange... And since all 8 of the crossed keys operate the common department entry door, each individual having an office inside that department would be given one of the 8 different keys that corresponds to which combination of auxiliary rooms in their department that they should also have access to and they don't have to carry three, four or five different keys to be able to do so and they would of course be issued their individual office key... This means that each person with an office within the department is issued only two keys for their department...

I hope that this posting has taught you something useful...

~~ Evan

[Evan]

YES... Also key 77777 would operate as well as any key which combines 2, 5 or 7 bittings... Its a long list... Here is some of it:
22225, 22255, 22555, 25555, 22227, 22277, 22777, 27777,
55552, 55522, 55222, 52222, 55557, 55577, 55777, 57777,
77772, 77722, 77222, 72222, 77775, 77755, 77555, 75555,
and on and on until all combinations of 2, 5 and 7 in any position are exhausted...

I don't know where I got the key of 77777 from, I guess I shouldn't have been writing posts when I was up all night being sick and watching infomercials... Those infomercials really mess with your mind and suck your brain right out of your head...

For the sake of argument lets say the key 77777 represents the fictional master key and the keys 55555 and 22222 are change keys cross keyed to operate the same cylinder... Just so you can get a taste of how crazy some cross keying can get...

My apologies on my mistake !

~~ Evan

[globallockytoo]

I have set up and installed many GGGMK systems for schools, universities with one or multiple campuses. Often, maison keying is requested to minimise the quantity of keys being carried.

When I set up a system, I ask for the names of all key holders and list them from top to bottom. Then I number and name each and every door (across the top of a graph page) and check mark which key holder is allowed to access what door. I can then produce an individual key (that may be different from each other) for each person and load the appropriate cylinder with that keying.

Most of my systems that involve multiple floors and campuses, I color code the keys to easily identify them. I have created sub master keys for cleaners/janitors, maintenance persons etc etc. Color coding is the simplest method for differentiating keys in a system.

@globallockytoo:

Those "My Key" matrix type systems really really suck when someone eventually ends up losing their key and the lock(s) for "their doors" need to be rekeyed... It often involves having to rekey more doors than if you keyed the locks to the building layout and function rather than the people using them... Such systems also often require extensive "double pinning" requiring two or more master pins in a chamber in several chambers in many locks in the system...

~~ Evan

It depends on your choice of cylinder product. Abloy or Bilock do not require multiple pins/stacks.

With many systems I have designed and installed, losing a key means removing (or replacing) that key only, without affecting any other keys in the system.

Sure, you still have to re-pin or re-disc those cylinders, but costs are kept way down and so is the inconvenience.

[Evan]

It depends on your choice of cylinder product. Abloy or Bilock do not require multiple pins/stacks.

With many systems I have designed and installed, losing a key means removing (or replacing) that key only, without affecting any other keys in the system.

Sure, you still have to re-pin or re-disc those cylinders, but costs are kept way down and so is the inconvenience.

Well one of these days if I end up a member of the advanced locks section on this site I will definitely ask you to elaborate more on this there, but I think that further discussion of those high security locks and how to create a master key system for them would not be appropriate in this particular forum section of the site...

You have definitely piqued my interests about how you would accomplish an extensive "My Key" matrix chart type "people and doors" system without reducing the overall cylinder security or the functional capacity of a keying system more than you would have if the system was designed for the function and layout of the building rather than being designed to the keyholders using it at the time it was installed...

~~ Evan

[dll932]

WRT Maison keying, I try to dissuade customers from it; it's convenient, but if you have to change out one key...


Putting random keys into a MK system destroys it. It get impossible to insure one key won't work another lock.