Masterkeying Lessons

[Eyes_Only]

Thanks, that'll save me some money to use for badly needed tools instead.

[Raccoon]

Eyes: If you're done with the book "Master Keying QBE", would you be interested in doing a pass-around; lending it to people on the forum?

[WOT]

I'd love to get my hands on Interchangeable Core Cylinders By Don O'Shall but I can't find it anywhere other than specialty locksmiths supply shops online.

Is this whole "security through obscurity" a big part of culture among locksmiths? I can't find it at public libraries either.

[Beyond]

I'd love to get my hands on Interchangeable Core Cylinders By Don O'Shall but I can't find it anywhere other than specialty locksmiths supply shops online.

Is this whole "security through obscurity" a big part of culture among locksmiths? I can't find it at public libraries either.

Libraries won't have it because it's not a popular item amongst readers. They generally only stock what they think the general public will want to read.

As far you not finding it, that's your own fault. I know of two places off hand that sell it without any sort of "proof" that you're a locksmith.

[WOT]

I'd love to get my hands on Interchangeable Core Cylinders By Don O'Shall but I can't find it anywhere other than specialty locksmiths supply shops online.

Is this whole "security through obscurity" a big part of culture among locksmiths? I can't find it at public libraries either.

Libraries won't have it because it's not a popular item amongst readers. They generally only stock what they think the general public will want to read.

As far you not finding it, that's your own fault. I know of two places off hand that sell it without any sort of "proof" that you're a locksmith.

I know I can find it. I just don't want to pay $69 for it. You can find quite a few books that talks about master keying and such at public libraries. I can't find O'Shall's book anywhere except a few places at full retail.

[Beyond]

I'd love to get my hands on Interchangeable Core Cylinders By Don O'Shall but I can't find it anywhere other than specialty locksmiths supply shops online.

Is this whole "security through obscurity" a big part of culture among locksmiths? I can't find it at public libraries either.

Libraries won't have it because it's not a popular item amongst readers. They generally only stock what they think the general public will want to read.

As far you not finding it, that's your own fault. I know of two places off hand that sell it without any sort of "proof" that you're a locksmith.

I know I can find it. I just don't want to pay $69 for it. You can find quite a few books that talks about master keying and such at public libraries. I can't find O'Shall's book anywhere except a few places at full retail.

More than likely, most of those books are from Bill Phillips. Check eBay. I paid full price for all of my SFIC books, they were worth every single penny.

[WOT]

I don't know too well about literature on master keying offered out there but I was considering the book "Basic Master Keying - QBE" by Don O'Shall and John Truempy offered here, http://www.lounginglizardpublishing.com/lizard.htm . Right now it's either this book or the FB master keying course I'm thinking of taking.

I think that guy doesn't like us. Varjael and some other guy as banned from his forum Institutionallocksmithing for affiliation with LP101...

[weerwolf]

Sorry to bumb an old thread , but I would like to input some more.
Here is how I would make it.

For a simple plan using 5 cilinders and a masterkey:

MK: 35424
C1: 35421
C2: 35422
C3: 35423
C4: 35425
C5: 35426

I make the variations on the final cut. This is for reliability reasons. The further to the front the master pins , the more they are used. Also , if it is a bit system , or you are using all variations on one cut , you end up with very deep cuts. A deep cut to the front of the key is allways bad news.

In this example the cilinder for C1 will be:
35431
35421
00003

(I've only put the 0 there so it would be displayed properly)
Because there is only 1 master pin , only 2 keys have acces to this cilinder. The masterkey (35424) and the C1 (35421)

Here is the same approach for a bigger system. Here I'm using 10 cilinders. Suppose its 2 floors of 5 appartements each.

MK: 35424
C1: 35431
C2: 35432
C3: 35433
C4: 35435
C5: 35436
C6: 35441
C7: 35442
C8: 35443
C9: 35445
C10: 35446

As you can see , I've used a variation on the last 2 cuts. For the first 5 cilinders , i'm using a 3 instead of 2 and for the other 5 , i'm using a 4. I'll allways try not to use the cuts of the master key in any key. This is to make sure ghost keys aren't in the other change keys.

A cilinder for C1 would now be:

35431
35421
00013

Because there are 2 master pins , there are now 4 keys that fit the cilinder.

35431 , witch is C1
35424 , witch is the MK
35421
35434

The last 2 are ghost or phantom keys.

Like I've said in the example , this is a 2 level appartment builing with 5 appartments per level.

Because I would vary the last cut in all keys for floor 1 (C1 to C5) and then vary the second last cut for the other floors , I can now add a Group Key for each floor.

This would be:
GK1: 35434
GK2: 35444

These keys are ghost keys for all the cilinders.

If the entry door needs to work with all keys , the pinning would be:

35421
00011
00011
00001
00001
00001
00001

You can then add another key , to only fit this cilinder. That would be 35447. This is why there is a 6th master pin for the last cut.

This system can also be expanded. Suppose another floor would be added:

C11: 35451
...
C15: 35456

When this system isn't large enough , you'll have to vary on 3 cuts:

C1 would then become

C: 35331

and its pinning would be:

35331
35321
00113

Because there are now 3 master keys , you'll end up with 8 keys in total that fit the lock:

35331 , C1
35421 , MK
35321
35324
35334
35431
35434
35424

The last 6 keys are ghost keys.
I allway try to use as little master pins as possible , to keep ghost keys limited. Its not just ghost inside the system , but an outside key can also have the right cutting to acces the cilinder.

To find the ghosts , I use the following technique:

I'll work on the last example

C1:
35331
35321
00113

So , I then note

35 and for the rest I use A and B. A is the shallow cut , B is the deep.

35AAA would be 35321
35AAB would be 35324
and I use this for the full list:

AAA
AAB
ABA
BAA
ABB
BAB
BAA
BBB

Its a simple trick I picked up , but its a lot faster than comparing all cuts to the pinning of other cilinders.

I hope this post was on any use to anyone. And sorry for the bad spelling , English isn't my primary language.

[freakparade3]

Weerwolf, no cut on a change key should be the same as the corresponding cut on the master.

[weerwolf]

Weerwolf, no cut on a change key should be the same as the corresponding cut on the master.

That would mean using master pins on each cut. 32 keys that fit the cylinder 30 of witch are ghost keys.

I don't really see the point in changing all the cuts between the master and the change keys. The only real advantage I can see is that its more difficult to reverse engineer a master key.
But , if whoever is trying to get it is profesional enough to do that , he can certainly pick the locks as well. And it the keys are a secure profile , its virtually impossible to do this anyway.

The way I mentioned in my post is how I was taught it. Maybe you use a different system in the US.

[straightpick]

Wrote up a small master keying system now that I have some free time and this is what I got at this point;

Master Key - 46486
Change Key 1 - 24264
Change Key 2 - 24268
Change Key 3 - 24624
Change Key 4 - 24628

Yes this WOULD work, however it is not secure at all. Take the first change key. There is a difference of 2 increments between the master key and change key in EACH chamber. This means that there is a master pin in each chamber. This creates two shear lines in each chamber. So your possible combinations are 2x2x2x2x2=32 possible key combinations that will open this lock. The same applies to the other three change keys. So there are 108 possible keys(if cut) that will open these four locks! First rule for picking a master key bitting (in a two step system) is to use the shallowest and deepest cut in the master key. The shallowest cut prevents any change key from being recut into a master key. Some manufacturers like Schlage reserve cuts 0,1 and 2 for master keys. You will never see one of those cuts in any keys for locks that you can buy off the shelf.

[straightpick]

freakparade3 wrote:
Weerwolf, no cut on a change key should be the same as the corresponding cut on the master.

Actually, Weerwolf is using a type of masterkeying that is very popular in the European countries. It is called the "rotating constant" or "hold and vary" method. This method goes against the grain of the two cut increment system in that some of the cuts of the master key must appear on each of the change keys. Some of the positions are held constant on the change keys and others are rotated, hence the name "rotating constant". This method actually improves security by using the least amount of master pins in each lock and it creates more change keys than is possible with the two cut system.

In his first example, which I take to be for a Kwikset type lock (only six depths), there are five change keys. Using the two cut system there would only be two change keys possible (if the master key was 1, you would only have a 3 or 5 cut, if it was a 2, you would have a 4 or 6 cut.) The only flaw is his choice of the master key bitting - should have the shallowest cut in one position on the key to prevent a recut into a master. I would have used his first change key bitting as the master bitting. But then again, I never use the single increment in a Kwikset lock, those .023" pins will jam in the cylinder.

You can also use this method with a two cut increment cut for the change keys. For example, a master key of 41253. You can have change keys of 41251,41255,41213,41233,41453,41653,43253,45253,21253,61253. That is 10 possible change keys with only ONE master pin in each lock. However, we would not use 21253 as this could be cut into a master key, so we have nine good combinations that only the master key and change key work - no ghosts.

The rotating constant method produces more change keys than the two cut system , but the two cut system produces more master keys. You CANNOT mix the two systems together, you must use one or the other. While it looks deceptively simple, however, you need a thorough understanding of it to prevent unforseen problems.

[weerwolf]

In his first example, which I take to be for a Kwikset type lock (only six depths), there are five change keys. Using the two cut system there would only be two change keys possible (if the master key was 1, you would only have a 3 or 5 cut, if it was a 2, you would have a 4 or 6 cut.) The only flaw is his choice of the master key bitting - should have the shallowest cut in one position on the key to prevent a recut into a master. I would have used his first change key bitting as the master bitting. But then again, I never use the single increment in a Kwikset lock, those .023" pins will jam in the cylinder.

I'm used to working with Cisa cilinders. These have 6 depths , but a 7cut is possible for keys in mast key systems.

You're right about the the ability to cut a masterkey out of C1. But as I've mentioned in my previos post , anyone who has the skill to make a master key out of a change key , will no doubt be able to pick the lock as well.

But I only used this as an example. I wrote them down last night , while I was watching Family Guy on tv. I started out from a key I had lying at my desk at the moment.
If it were a real situation , I would make the master key the most shallow. This also makes pinning easier. You insert the master key in the barrel and start pinning. Then withdraw the master key and fill the barrel with master pins. You will immidiatly notice when you've made a mistake.

Wolf

[tacedeous]

I just wanted to say I finished the master keying section in the FB course (happy with course so far but not this lesson) I learned more in this thread than in the lesson... THANKS!

but a question.. I hope this doesent sound dumb but I have a question on pinning (please keep in mind im not done with the course) I understand breaking down the keycuts, into the masters and change keys, but how do I figure out the pinning of the master pins? in the course they where all the same size and i had to file them.. this does not seem professional, do pinning kits come with incremental master pins of different sizes?

If so, one would just subtract the size of the regular pin from the master pin above?

I hope that makes sense...

[globallockytoo]

the bottom pins are the shallowest depths of all keys in the system that fit that barrel.

the master pins are the depths required to allow all the different keys to work that barrel.

eg: 54325 Key 1
38761 Key 2
70349 key 3

Bottom pins = 30321
Master pins = 24424
Master pins = 24-24

This will allow all 3 keys to work that cylinder.