”Its name comes from the fact that it has two key blades (the part which activates the bolt) at each end of the key, rather than the usual single blade”
How does that lead to the name “Berlin key” or either of the German names? I would guess “Berlin key” comes from the fact that it predominantly is used in Berlin.
”After unlocking the lock, the key must be pushed all the way through the lock and retrieved on the other side of the door after it has been closed and locked again”
I think the main features are:
- the key cannot be removed when the lock is open.
- you can remove the key from the other side of the door from which it was inserted.
It seems you can lock the door from the side it was unlocked from, and remove the key from that side, too. You only have to push it all the way through if you want the door closed and locked with you and the key on the other side of the door.
I also think you can close the lock and remove your key when the door is open.
The other German names for the key describe different aspects of it: "Durchsteckschlüssel" translates to "push-through-key" and "Doppelschlüssel" translates to "double-key".
If you are more curious about the thing, there is a book by philosopher Bruno Latour on the Berlin Key where he describes the thing with the sociological situation that lead to it if I remember correctly (was a few years ago when I read it).
Edit: The basic idea is that in this kind of multi-party environment they wanted to make sure the door is always locked in the evening (when people return). To unlock the door you have to push the key through. Once you are inside you can get the key back, but only if you lock the door behind you. So once the door is locked, it stays locked, unless someone from the inside leaves it open on purpose. This way people cannot "forget" to leave it open.
May I ask why you read a book on it? Just interested in locks/security or lock picking?
I’ve found reading general interest books are a great source of inspiration regardless of your speciality. So I like picking up random topics. For ex: a book on ants which had utility in simple autonomous network design.
During the day, the front gate can be opened from the outside with just pushing a button that unlocks the door. At night (from 20 or 21 or so), the button stops working, you need the key. It can be opened at any time from the inside without keys. So it's more or less implementing the same protocol, but electro-mechanically, so there is no need for the trick with pulling the key inward.
With the Berlin key if you want to get your key (ostensibly you do and certainly don't want someone else to take it) you have to close the door. Of course you can still leave it propped open but unlike in your modern setup you actually have some stake in making sure it is closed.
Edit: I read the first paragraph twice and then to confirm my understanding I turned to YouTube.
* have to clone the key from fairly dark and jittery cell footage
* have to identify the location in a city of four+ million people
Once you did that you’d be able to access a commons area of a hotel?
I’m not convinced the risk is all that great :)
Until recently, this sentence used to be “Its particularity comes from the fact …”:
1. You can only remove the key if it is locked.
2. You can't lock it unless the door is closed.
That ensures that when you have the key then the door must be locked and closed.
The think about pushing the key through they door is just because otherwise you have no way to start inside the room, unlock and open the door, and then lock it behind you. Remember while the door is unlocked you can't remove the key. So if you just go outside and shut the door the key is now inside... and the only solution is to pull (or push) the key through to the door to the outside. Then you can lock the door and remove the key.
Yes, it's from another era, when the consumer was not expected to be a fool...
I suspect it may even be illegal today.
In the US if I checked out a rental home as a possible place to live and it had any one room where you could lock someone in and they would be trapped I'd wonder what weird shit happened there.
I suspect that is a result of different cultural expectations related to who should be able to afford to own their own home - even if the homes don't last very long.
From my understanding the switch to stone was mostly for fire resistance. City walls lead to very dense cities where fire could spread rapidly. Stone walls with clay tile roofs make it much harder for any fire to spread within a building and to other buildings.
Today we would have the fire fighting techniques and more fire resistant wood panels, but old habits die hard (and we are used to buildings standing for hundreeds of years)
If Switzerland had the US rate, ~75 more people would die every year.
If the US had the Swiss rate, ~2800 people would live to see another year.
Put in normalized terms,
- 0.00028% of the Swiss pop. dies from fire annually
- 0.00116% of the US pop. dies from fire annually
- 0.001% of the US pop. dies from drowning annually
- 0.001% of the US pop. dies from exposure to mechanical force annually
- 0.006% of the US pop. dies from gunshot annually
- 0.01% of the US pop. dies from falling annually
- 0.015% of the US pop. dies from road injuries annually
- 0.03% of the US pop. dies from respiratory illness annually
Here's  a visualization I made of causes of mortality a few years back. Play around with this a little bit; it's pretty interesting looking at actual mortality rates.
Anecdotal, we had a fire in my building because the wrong type of lightbulbs were installed in the hallways and because of their size, they were too close to the drywall which in turn caught fire. So.. yeah. Matchstick.
Which to be honest says not a lot about anything, because this isn't that unusual in Central Europe.
Also: a lot of the old wooden houses are far better in terms of fire resistance than you'd suspect on first glance, wood often outperforms concrete and steel when it comes to structural integrity in a fire.
I don't know about the straw thing, I only know it mixed with clay.
The home in question belonged to the extended family of my host family while I was an exchange student. I went with them to a maintenance day and did wallpaper. I got a very close look at the walls, not to mention the repeated lectures on what a firetrap it was.
Trust me, it was.
Also US electric plugs are inherent fire hazards, much more so than anything you find in europe.
It may or may not be the case that US houses catch fire more often, but fire is always a very big deal if it does happen and then you really don’t want to be locked inside the ‘fire-proof’ house.
Excuse me? What exactly is "low quality wood"?
What are you claiming determines "wood quality"? And are you insinuating that "high" quality wood somehow... burns more slowly or something? All of this is new to me...
Also the vast majority of US homes are not prefab at all, not sure what that has to do with anything. And I'm not aware of a correlation between prefab construction techniques and fire hazards.
Now it's absolutely true that different parts of the world use different materials -- cinder blocks vs. wood vs. stone -- but that has much more to do with climate, available materials, and century of construction, rather than "quality".
New homes in America tend to be wood-framed. Cheap materials are popular in American home construction.
I would add this article https://www.bloomberg.com/news/features/2019-02-13/why-ameri... which explains my matchstick metaphor
> Building codes evolved, too, as insurers and fire-safety-equipment manufacturers pushed for scientific, “performance-based” codes that emphasized lab-determined fire-resistance ratings over specific materials and incorporated new technologies such as the automated fire sprinkler.
> Stick construction allows builders to use cheaper casual labor rather than often-unionized skilled tradespeople. And it makes life easier for electricians, plumbers, and the like because it leaves open spaces through which wires, pipes, and ducts can run. Still, there’s a reason why stick wasn’t the default for big apartment buildings until recently, and why these buildings are limited in height: Sticks burn.
Another reason you missed is money. Ticky tacky is cheap and ubiquitous in your average dwelling in America.
However in the end you are responsible for your own safety. If you are in a room with a lock, make sure you don't lock yourself in. Locking people in is a bad idea regardless of situation (and I am pretty sure it is illegal to do so against their will).
As an American I still find it weird that it is even possible to lock someone in: anyone I've asked has had stories about young kids locking themselves or their parents in or out of a room with no easy way to fix the situation (resulting in things like balcony jumping). I don't see the benefit in designing things that way.
Because of that we can call the firefighters at not cost, even false alarms are not penalized. But no mandatory smoke alarms or fire extinguishers even though this building still has a working old time furnace for heating. Go figure.
Maybe they expect the Swiss neighbor watch to raise an alarm more accurately than a smoke detector would. Old Swiss people are always suspiciously watching over their neighbors.
No one checks it for individuals though.
A large part of German Fire Code is to prevent the spread of the fire and contain it in the rooms where it started for as long as feasible. The lowest rating a fire location can have is E30, meaning the fire takes 30 minutes to "break out" and spread further. The building owners likely also benefit from grandfathering (ie, special building fire code, which depends on federal state in germany).
It also depends on the fire load, ie, how much flammable material the house contains. A concrete or stone house that contains only flammable material as part of furniture isn't a huge fire load and you don't need heavy doors to prevent fire from spreading out of a single flat, a normal door will likely already prevent spread.
Isn't that the case for most doors that lock? You can't leave through my (brand new, to-code) front door from inside without a key to unlock it first.
It wouldn't be secure if you could open it without a key - isn't that the whole point of a lock with a key?
I'm sure I'm just ignorant, but it sounds like your lock is on backward. Every front door I've ever seen can be unlocked from the inside without a key.
Could you link to a lock that's similar to what you're talking about? I'd feel very uncomfortable entering a house where I couldn't leave without a key.
It's the same from both sides (except for the screws, you can only unscrew it from the inside). Both the inside and the outside have a keyhole, and while a key is in one side you can't put a key in all the way from the other side (this way you can lock from the inside, leave the key in, and even someone with the key can't get in).
Normally people don't lock the door while they are inside (maybe at night), on doors facing outside the door handle can't be turned from the outside and you have to use the key to get inside even when the door isn't locked.
 because the previous owner's tenants had broken the door down at some point, and he had replaced it with an internal door, in which for some reason he had installed the lock upside-down
99% of the time most people use the latch, which would be a Yale lock in the UK, or a Abloy in Finland. You'd usually use the extra-lock if you went on holiday, or something similar. Most of the time it would be unused.
I understand the reason for it but I wish a better solution could be found.
Why not? Someone smashes a window, crawls through it, walks around to unlock the main door, through which the burglars unload your stuff. It’s a lot harder to move things through windows.
Interestingly, the door locks commonly used in the US are much less secure in general than those typically seen in Europe. The average US household deadbolt can be opened with fast lockpicking techniques (raking, zipping) while European ones usually can't. That may be a surprise given the relatively high crime rate of the US.
One crime that isn't as high in the US as most European countries, however is burglary of an occupied residence. It seems the increased risk to the burglar's life may have some deterrent effect.
They have a knob that doesn't have a locking mechanism at all and a deadbolt that locks from the inside without a key, but cannot be locked without a key if you leave.
I think in some English rental properties these are compulsory. (Or Yale latches).
But having it not work this way is very unusual in the states, while common to not exactly rare in some other places.
I have never seen an exit door in Canada, or the United States, that could not be opened from the inside. I'm reasonably confident that is super illegal in those countries.
I suppose this can be avoided by not having any windows close enough to your doorknob that you could reach the lock from them. But people could just break a window and climb through into your house, anyway.
> Isn't that the case for most doors that lock? You can't leave through my (brand new, to-code) front door from inside without a key to unlock it first.
Do you live in the US by chance? In my jurisdiction double keyed deadbolts for example are not up to code for residential use, and for those applications the deadbolt must be keyless on the egress side.
Logically, this seems sound as you don't want to be scrambling for keys if your house is on fire.
Just to clarify, after you lock your front door with the key, it’s impossible to unlock the door from the inside without a physical key?
The vast majority of locks have a physical unlocking mechanism on one side (one side is unprotected, usually the inside)
Not where I live. Sure the lock that you use to stop it blowing open in the wind (1) when you are at home has a latch on the inside (making it easy to open door to visitors etc), but you also have the real lock that you use when you leave the house require keys from either side (2).
I think most home insurance in the UK would either not insure you or your premiums would be super-high if you only had the latch and not a proper secure lock.
Random image from the internet showing typical UK front door locks - latch at the top (openable from inside without key), proper secure mortice lock at the bottom (key needed from both sides): https://i.pinimg.com/originals/1b/a1/63/1ba1634b8b6b9c5135b6... or https://i.pinimg.com/originals/a1/7b/77/a17b77bf1ad7a909a0bd... - in the second picture if it just had the latch it would be absurdly easy to break into: just break the glass and open the latch!
1 - https://www.screwfix.com/c/security-ironmongery/night-latche...
The mortice locks are harder to pick and are usually substantially sturdier in construction. In the UK at least, the mortice lock is physically inside the door structure (1) whereas the latches that don't need keys are attached on the door (2).
We recently had a break-in in the block of apartments where I live where the latch attached on the door was broken off by people forcing a door. If there had been a mortice lock, they'd have to break the door frame or the door itself, rather than just bust the weak latch lock off the back of the door (in this case the door opened outwards, so they just pulled on the door handle whilst bracing a leg against thethe wall and the latch came right off the back of the door)
1 - https://www.buildingsheriff.com/mortice-lock-costs_files/sta...
2 - https://www.diydoctor.org.uk/images/nightlatch.jpg
Maybe where you live. I’ve never seen a lock like that except in a hotel.
(If a door is part of an exit route, you probably can't require a key to open it.)
I doubt that’s theoretical. Kids playing in the garden and on the street could easily use that ploy.
This is achieved by only allowing the key to be inserted or removed when it's in the locked position. The push through is to allow them to lock the door on either side.
1: it's a key that can only be inserted or removed when in the locked position.
2: It can be only be pushed from one side to the other when in the unlocked position
Therefore you can unlock the door on one side to let someone in, lock the door on the same side and remove your key again.
Alternatively you can unlock the door then push the key to the other side, lock the door on the other side and remove your key.
This is the original technical document on this key.
There is a larger group of areas where this is perceived to be true, even if it isn't.
A good feature to have on otherwise normal doors so that they only ways to lock it is to be inside or outside with the key. I now have a greater appreciation for deadbolts.
Seems like an elegant, physical embodiment of resource acquisition, state management, and release. Albeit uncomfortable in your pocket.
Comparisons to C++ std:: on some of these counts may be valid.
The gate was usually open, and then couldn't be locked with the key. If the gate was closed, it could only be left again in the closed state.
The house is next to the Olympic Stadium, so the gates are closed when there's a football game, concert or other event.
The photo they used to accompany the outrageous story was hilarious. Nowadays, that doesn't seem as far-fetched of an idea, with somewhat similar futuristic key implant methods becoming more readily available.
I think the physical key has the same blade shape on either side.
The companion software would decrypt the ciphertext but prevent exporting the cleartext, forcing the user to first re-encrypt the text first.
You stick your token in, you gain access to a facility, and then to get your token back, you must restore the facility to its proper state. Additionally, in both cases, the facility you're unlocking happens to involve physically moving an object around.
Which I have done, multiple times.
The subtitle of the essay is "Doing Words with Things", which is a reversal of the famous essay of John L. Austin "Doing Things with Words". Austin pointed out that words have practical effects. Consider the speech act 'I do', when two partners marry: it are the words that have a specific effect in real life.
Now Latour claims that we -- philosophers, sociologists, but others as well -- have to pay attention to the effects material objects have on people interacting with them. He claims that a specific way of acting can be inscribed in an artifact.
So the key is an example of this: you can only take your key out, if you lock the door behind you. Rather than having a message next to the door saying "Please lock the door behind you", this type of behaviour is enforced through the artifact itself.
So social mores or norms can be inscribed in and enacted through material objects (and not just through words).
At least that's an ELI5 version of what the essay intends to convey.
Also this clock design seems unnecessarily inefficient. Why divide 24 hours in multiple of 5 hours instead of the much more natural 6? This way it would be a lot easier to decode AM/PM.
I realize that it's about art more than practicality but I don't really understand why that encoding was chosen.