I hope this can be a cautionary tale about master keys and safes. Our story starts late one night or early one morning when unknown people* broke into a pharmacy. More accurately, they broke into the bigger building as a way into the pharmacy and damaged five doors before getting to the safe and lifting it. If you are a building manager, this instantly makes this a bad day.
Our shop was called since the long gone safe contained an exterior key and a master key for all internal doors. Doubtless the 'perps' were after drugs or cash, but the keys were in the safe. I asked after the safe a bit and found out it was a microwave sized box from Costco -- a fire safe only. Unanchored, it was easy pickings. This pharmacy does not fill so called 'triplicate prescriptions' including the narcotics. However, there was no external sign saying this to all who walked in or past on the sidewalk. I suggested such a sign and the next safe be burglary rated and anchored.
[If locksmiths and builders are in an arms race with thieves, I always suggest after a break and enter the client try to jump two levels in barrier if possible. If you put back the same hardware as was there, you already know that same criminal can get in. Should they try with just the next level of tool and you only go up one notch in hardware, they will still get in. Sometimes there are practical ways to do this and sometimes there are not.]
Now, back to the keying. The outside of the building was on its own key and keyway. We could do this fast but knew the key distribution is often the problem. Property managers know this is a real hassle too but in this case unavoidable.
The master key was a different problem. We had swept the building less than a year ago and they had just started on a fresh master key. The manager did not want to do that again, but I also found out the public could get into the upper floors for a few hours after the main floor was closed. This generated a great vulnerability to leaving the old master in place. Also, we knew none of the office keys were gone. I was asked if I could change just the master and leave the rest. Without seeing the pinning tables, I only gave a maybe.
Back at the shop, I found the file and had a careful look. It was a 5pin Schlage C system with 4 chambers progressed. It had only two layers -- the master key and the user keys.** Given this, there are 4^4 = 256 theoretical user keys. Having seen the building, I knew it was not even close to using half of these but I did not have the new master yet.
Here is the system with made up numbers.
Master Key 76543 with the 7 held in all locks and all keys. This brand of lock used fixed parity so if the master uses an even number in a cut, the user keys work from the remaining even numbers. Likewise for the odd cuts. The progression counting was kept simple from the tip of the key back.
This gives a KBS (Key Bitting Array) as follows.
76543 Master
-8765 Possible progression cuts
-0987
-2109
-4321
-4321 Sequence of progression
When looking at the issued keys both when the shop had rekeyed the entire place and a few changes since, I found every user key started with 78. This meant the second chamber in every lock had a 2 master wafer and I could change this to get my new master and retire the stolen key. In fact, there were 3 choices for the new key -- 70543, 72543 and 74543. I picked the 72543 and went to the bottom of our computer records for the building and marked all the user keys starting 72 as 'Do Not Cut'. We lost about 64 possible keys but still had 192 theoretical user keys for the future of which only about 40 were already issues.
I had told the manager it would take some luck to be able to find a usable replacement master but in this case it worked out. I went back to the site and visited every lock to pull the stolen master and install the new.
[We do not always get lucky. We set up a simple 5pin Schlage system for a growing business and based on their estimates held one chamber, used two for a master key at each site and the last two for keys within each site. The roll over in managers exceeded estimates and the expansion to new sites was much higher than first planned. This system has hit the wall and all the possible keys have been used up. New plans have been debated.]
* I will use the plural but it could have been just one person.
** In the trade, these are called change keys but thinking I might reach a wider audience I will call them user keys. And yet, the janitors 'use' a key to open all the doors and it is the master key.
--- --- --- --- ---
The contents of this post are released for non-profit or educational use in whole or in part provided this statement and the attribution below are kept attached.
Laux Myth ... Thoughts From a Locksmith
By MartinB, Found @ http://lauxmyth.blogspot.com/
Thursday, February 10, 2011
Tuesday, January 25, 2011
Exploding Hinge Bearings and Fallen Doors
I was called to a retail store in an emergency as the dogging was not working on the front latch lock. The key had opened the place but the latch would not stay in to allow customer access. They had moved a floor mat into the door and put up a sign to ask everybody to leave the mat there. It worked but with freezing temperatures it was a short-term solution.
The problem turned out to be strangely minor as the door had a one inch mortise cylinder and it was wound ALL the way in without any rings. There was a protective plate mounted over the rim of the cylinder so this was visually good. It also prevented using tape to hold in the latch or see the problem found later. However, the cam on the back of the cylinder was operating the very end of the dogging lever on the FAR side of the latch lock. Surprising to me it was not interfering with the cam unit for the inside lever handle but it must have been very close. Some strong staff member had turned the key hard enough to bend up the dogging lever and after that is was not in place to work. The solution was to move the outside cylinder out with a trim ring under its face. Since the dogging levers are "L" shaped and extend from the side, they are strongest if the cam acts on them close to the lock body wall. Simple and done.
Not so quick. In a routine way, I put the face place back on and let the door close. When I looked with a flashlight at the strike the latch was coming in low. It was the small Adams Rite strike as shown above. The latch was riding on the metal around the lower screw and was catching on a tiny lip along the face of the strike. (This drawing does not show this detail well. Those who know this hardware can look at one to see this.) The strike was previously filed down to get the latch to fall in but it was now lower still. In fact it was touching the screw itself. At the same time, the tops of the doors were touching although not as much as we sometimes see. This points me to the hinges.
This is a difficult customer service case. We were called to solve the one problem as identified by the customer. And now I see a bigger and more complex problem but this door could have been pulled open with a good strong tug and not mentioning it to the manager is not a good ethical solution either. I spoke to the manager before doing more and showed what I was seeing with my flashlight.
One solution on the short term had already been tried and that was to file down the hole in the strike and there was room to go lower. However, with the latch hitting the lower screw, you can not go that low. Given it was a double door set and I did not have hinges with me, I pulled one hinge from the centre of the inactive door and put it in the middle of the active door to lift it some and also did some filing to lower the strike hole. This was enough to lift the door on a very cold day. (A bit of nasty work in cold weather but they did give me some free coffee. Yeah!)
We are booked to get back and replace all three hinges to lift the door a bit more.
What did I see?
This is the one removed hinge closed next to a new hinge for comparison. The rust is clear but not really the problem itself. However, you can see the two leaves are no longer at the same height. The door leaf is about 1/16 of an inch lower and under of the door even a bit more.
This is a detail of the failing hinge. You can see the bearing has bulged out and I have seen cases where they have shards of metal breaking away from them. Also on the next joint down you can see the gaps developing as the bearing let the door drop. I could not find a way to show two other failures happening here. The hinge pin thins as it rusts or else the inside diameter of the knuckle increases or some of both and the two hinge plate can move left and right as well as up and down. This also means they can angle and twist compared to each other too.
Another feature of a failing hinge is that the metal wears away on the part of the swing the door passes through most. This has the effect of making the hinges into little ramps. And since this problem happens fastest if the hinges are not lubricated you get raw rusted steel on rusted steal so the door is harder to pull open and the closer must work harder. You can usually must slow the closer down once you change out worn hinges.
--- --- --- --- ---
The contents of this post are released for non-profit or educational use in whole or in part provided this statement and the attribution below are kept attached.
Laux Myth ... Thoughts From a Locksmith
By MartinB, Found @ http://lauxmyth.blogspot.com/
Friday, December 31, 2010
The Hard Disc Drive in the Photocopier
This is a BIG heads up for any company which leases a digital copier and for anybody who has used one. Which is all of us!
Found at Flixxy was this news story from CBS News
Look at http://www.flixxy.com/copy-machines-security-risk.htm
or
The Danger of Digital Copiers - Who Knew?
http://www.cbsnews.com/8301-31727_162-20002830-10391695.html?tag=mncol;lst;2
(The CBS viewer did not play well for me but you may have better luck.)
It reports that most digital copiers since 2002 have built in hard drives which store EVERY page copied onto a hard drive. They bought 4 used copiers and found much sensitive information. Who knew they kept all that? Seems many in the trade did but all point to somebody else have told the end user. One company offers an add-on package to clear the hard drive at a stiff price.
I am wondering why this drive can not be cleared from the top end display any time the user wants to do so for free. Sheesh! Meanwhile, all kinds of personal information about you can be leaked all over the place.
What to do?
1. Careful what you copy at a rental location. Anything personal stays there.
2. Dispose of any copier instead of passing back to the lease company. (Or get them to pull the drive from it before you sign it back.)
[Note on publication date. I was trying to edit the posting date of some other post and this was 'moved'. The program does not seem to tell me when it was first posted so I put it at the end of 2010. Seemed easiest.]
Found at Flixxy was this news story from CBS News
Look at http://www.flixxy.com/copy-machines-security-risk.htm
or
The Danger of Digital Copiers - Who Knew?
http://www.cbsnews.com/8301-31727_162-20002830-10391695.html?tag=mncol;lst;2
(The CBS viewer did not play well for me but you may have better luck.)
It reports that most digital copiers since 2002 have built in hard drives which store EVERY page copied onto a hard drive. They bought 4 used copiers and found much sensitive information. Who knew they kept all that? Seems many in the trade did but all point to somebody else have told the end user. One company offers an add-on package to clear the hard drive at a stiff price.
I am wondering why this drive can not be cleared from the top end display any time the user wants to do so for free. Sheesh! Meanwhile, all kinds of personal information about you can be leaked all over the place.
What to do?
1. Careful what you copy at a rental location. Anything personal stays there.
2. Dispose of any copier instead of passing back to the lease company. (Or get them to pull the drive from it before you sign it back.)
[Note on publication date. I was trying to edit the posting date of some other post and this was 'moved'. The program does not seem to tell me when it was first posted so I put it at the end of 2010. Seemed easiest.]
Can you have a double-sided deadbolt on your house?
I really have to start this answer by saying I am writing for where I live and work. Laws differ in other places but the reasoning for some of this shines through regardless of where you live. Also, in this context your house is where you live and own. Sometimes law distinguishes between owning the house and simply renting it.
First, the law. You can not put a double deadbolt* on a fire exit since people must have an easy path out during an emergency. In Canada, this mean a functioning adult or child above sixish can get out of a room or a building without special tools or knowledge. A key is considered a special tool. Also, after the building reaches a certain size and/or expected occupancy, it must have two or more exits.
Second, more law. If you own your home, you can legally do stupid things.
Finally, the practical. If unblocked exits are good in public places in lowering the number of deaths in fires and other emergencies, then exits are also good in a house. Consider other options before you install a double deadbolt such as a metal grill over a window in the door or installing the deadbolt below the handle so an arm thru the broken window could never reach the inside anyways.
However, you MIGHT consider a double deadbolt in some narrow situations. I ask my customers where everybody sleeps and to think of what is the primary exit if a fire happens at night. You would NEVER put a double dead bolt on this door. You may also want to skip a secondary door. However, I have seen houses with a third and fourth door onto a deck or into the garage. (You would not normally exit in a panic via a garage but that really depends on your particular floor plan.)
If you think sealing a door against a broken window attack with a double deadbolt is worth the risk, then you should also be adding a glass break sensor to that window so your alarm response is instant if it gets broken. Another good idea is to hang a key close to the door so if this door must become the tertiary** exit, then it can be opened quickly. The practical viability of doing this depends on the physical and mental condition of the most vulnerable person living in the house.
Some of the NEVER even consider it situations would include:
• Granny uses a walker
• Toddlers live in the house
• Only one door
• It is a solid door
• The key will be stored in the inside cylinder
• No key will be placed permanently near it
As you can tell, I actively discourage such deadbolts. In fact, most of the time it is a matter of telling the client it can not be done due to codes and our client base will find other solutions. I hope you do too unless it truly meets a critical security need. After all, if fire exits are a good idea in other places, you family and friends deserve them also.
---------------------------
*This kind of deadbolt is most formally called a double cylinder deadbolt but it is also called a double sided deadbolt or simply a double deadbolt. Regardless of how you say it, the lock is operated by a key from the outside and also by key from the inside. Only a key holder can open the door.
** It means third.
--- --- --- --- ---
The contents of this post are released for non-profit or educational use in whole or in part provided this statement and the attribution below are kept attached.
Laux Myth ... Thoughts From a Locksmith
By MartinB, Found @ http://lauxmyth.blogspot.com/
First, the law. You can not put a double deadbolt* on a fire exit since people must have an easy path out during an emergency. In Canada, this mean a functioning adult or child above sixish can get out of a room or a building without special tools or knowledge. A key is considered a special tool. Also, after the building reaches a certain size and/or expected occupancy, it must have two or more exits.
Second, more law. If you own your home, you can legally do stupid things.
Finally, the practical. If unblocked exits are good in public places in lowering the number of deaths in fires and other emergencies, then exits are also good in a house. Consider other options before you install a double deadbolt such as a metal grill over a window in the door or installing the deadbolt below the handle so an arm thru the broken window could never reach the inside anyways.
However, you MIGHT consider a double deadbolt in some narrow situations. I ask my customers where everybody sleeps and to think of what is the primary exit if a fire happens at night. You would NEVER put a double dead bolt on this door. You may also want to skip a secondary door. However, I have seen houses with a third and fourth door onto a deck or into the garage. (You would not normally exit in a panic via a garage but that really depends on your particular floor plan.)
If you think sealing a door against a broken window attack with a double deadbolt is worth the risk, then you should also be adding a glass break sensor to that window so your alarm response is instant if it gets broken. Another good idea is to hang a key close to the door so if this door must become the tertiary** exit, then it can be opened quickly. The practical viability of doing this depends on the physical and mental condition of the most vulnerable person living in the house.
Some of the NEVER even consider it situations would include:
• Granny uses a walker
• Toddlers live in the house
• Only one door
• It is a solid door
• The key will be stored in the inside cylinder
• No key will be placed permanently near it
As you can tell, I actively discourage such deadbolts. In fact, most of the time it is a matter of telling the client it can not be done due to codes and our client base will find other solutions. I hope you do too unless it truly meets a critical security need. After all, if fire exits are a good idea in other places, you family and friends deserve them also.
---------------------------
*This kind of deadbolt is most formally called a double cylinder deadbolt but it is also called a double sided deadbolt or simply a double deadbolt. Regardless of how you say it, the lock is operated by a key from the outside and also by key from the inside. Only a key holder can open the door.
** It means third.
--- --- --- --- ---
The contents of this post are released for non-profit or educational use in whole or in part provided this statement and the attribution below are kept attached.
Laux Myth ... Thoughts From a Locksmith
By MartinB, Found @ http://lauxmyth.blogspot.com/
Monday, October 11, 2010
Washroom Fire Code Violation
I was out for coffee last night at a very large chain. If you live in Canada -- or even if you do not -- you may know it. You can roll-up the rim to win. On the washroom was a simple double sided deadbolt. You know the kind. It makes a prison cell in waiting.
Now as a matter of practice, we are not to 'interpret' fire codes but one line which is a guiding principle run something like the following. A capable person can exit from the room or building without special tools or knowledge. Not much interpretation needed to know a double deadbolt fails this completely. And yet, the hardware exists to do this right. Just off the top of my head are two models which allow a thumbturn inside to only unlock the door so that nobody can lock the multiperson bathroom upon entry. (Large buildings end up with problems like graffiti, drug deals or sex in washrooms if you allow the door to be lockable.) I know the hardware I am thinking is more expensive than the residential mess which was in use but a simple rope would be cheaper than a proper seatbelt. You get my point. They have the cash to use flat-screen TVs to advertise menu items, they can afford good hardware too.
However, this raises another issue. We were encouraged by a member of our local fire department to report violations when we see them and they would investigate. Usually, this mean shooting yourself in your foot since it is your own customer where you find the violation. Should I report this problem? I could get hate from many another locksmith and countless in-house fixers. I would like to hear from you on this.
Now as a matter of practice, we are not to 'interpret' fire codes but one line which is a guiding principle run something like the following. A capable person can exit from the room or building without special tools or knowledge. Not much interpretation needed to know a double deadbolt fails this completely. And yet, the hardware exists to do this right. Just off the top of my head are two models which allow a thumbturn inside to only unlock the door so that nobody can lock the multiperson bathroom upon entry. (Large buildings end up with problems like graffiti, drug deals or sex in washrooms if you allow the door to be lockable.) I know the hardware I am thinking is more expensive than the residential mess which was in use but a simple rope would be cheaper than a proper seatbelt. You get my point. They have the cash to use flat-screen TVs to advertise menu items, they can afford good hardware too.
However, this raises another issue. We were encouraged by a member of our local fire department to report violations when we see them and they would investigate. Usually, this mean shooting yourself in your foot since it is your own customer where you find the violation. Should I report this problem? I could get hate from many another locksmith and countless in-house fixers. I would like to hear from you on this.
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