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Questions tagged [locks]

Use for questions about the security of physical locks, as opposed to e.g. write locks on a database.

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157 votes
12 answers

4-dial combination padlock: Is it more secure to zero it out or to blindly spin the dials after locking?

I am partially responsible for some resources protected by a 4-dial combination lock like this one: There are two things that people will usually do after they've locked it: reset all the digits to ...
Peter Schilling's user avatar
154 votes
3 answers

Does pressing a car remote many times offer denial of service attack for rolling codes?

My understanding of remote car key fobs, and similar security devices with rolling codes, is that the key device is a transmitter that, each time the button is pressed, sends the next secret in a ...
Oddthinking's user avatar
  • 1,817
121 votes
11 answers

What's to stop someone from 3D print cloning a key?

My friend just posted a picture of her key to instagram and it occurred to me that with such a high res photo, the dimensions of the key could easily be worked out. Therefore the key could be ...
personjerry's user avatar
  • 1,246
96 votes
3 answers

What is the purpose of the rotating plate in front of the lock?

I am now in Poland and see these everywhere: The plate can rotate freely,when you insert the key, matching the groove, you rotate the key so it is aligned with the lock and then insert the key. What ...
Thomas's user avatar
  • 841
80 votes
6 answers

Can a lock picker slowly undermine the security of a deadbolt door?

I have a space for computers secured with a simple deadbolt. Someone keeps coming to pick the lock. While working there, I have scared them away three times. There are cameras, but not in useful ...
Village's user avatar
  • 863
51 votes
1 answer

Vehicle remote key security

How secure are car remote keys? When you lock or unlock your car, can someone spoof or make another remote key? How do car remote keys work? Do they use some kind of private/public keys, encryption? ...
Guntis's user avatar
  • 745
23 votes
4 answers

What are the alternatives to door passcodes?

Passwords have been a problem since the dawn of computing. They tend to be either so complex that no one can remember them, or so obvious that anyone could guess them. ... Some users ...
storm's user avatar
  • 1,742
15 votes
3 answers

How many unique house keys can possibly exist?

A Yahoo! answers user suggested that there are 5^5 possible unique configurations for a physical key, but the answer wasn't sourced. I wondered if anyone had similar numbers for how many possible key ...
Lou's user avatar
  • 315
14 votes
1 answer

How do rolling code fobs and receivers synchronise?

This is a follow-up question to my earlier one: Does pressing a car remote many times offer denial of service attack for rolling codes? I want to emphasize that I am asking this question more to ...
Oddthinking's user avatar
  • 1,817
7 votes
2 answers

Should magnetic locks automatically release in the event of a fire alarm?

Basically what the title says, you'll find many buildings have these types of door locks which can usually be opened by using a RFID token. While this example photo is glass, lets assume that the ...
NULLZ's user avatar
  • 11.5k
6 votes
4 answers

Are keys or RFID tags more secure access control solutions?

Just musing to myself, what is the preferable access control mechanism in high security environments? Locks and Keys or RFID tags? Going under the assumption that the locks/keys are not knoow to be ...
NULLZ's user avatar
  • 11.5k
3 votes
2 answers

Padlocks suitable as teaching aids for public key cryptography - do they exist?

When explaining public key encryption, people commonly use the imagery of keys and padlocks. However, most padlocks have only one key (i.e. only one bitting), and work like this: The padlock can be ...
sampablokuper's user avatar
3 votes
1 answer

Do dial locks have repeated numbers?

Can dial locks, such as the one below, have repeated numbers in their combination? For example, the combination 10-39-10 has the number 10 repeated twice in it. If so how often is this the case?
Unknown's user avatar
  • 153
2 votes
1 answer

How vulnerable are rolling codes used in car keyfobs to simple replay attacks?

I've read this question - Vehicle remote key security, and I have a few simpler questions that are not addressed in that one. I just received a whatsapp viral forward raising a few claims regarding ...
Ankush Jain's user avatar
2 votes
2 answers

Electronic security lock code length

I am debating with a friend about the security of a building lock that uses four user-selected digits as input. His argument is that it's enough physical security to deny someone access long enough ...
ipartola's user avatar
  • 121
2 votes
1 answer

How secure is BLE for a door lock

I am interested in setting up a trigger that can unlock door locks using an iPhone. The lock and unlock mechanism is not an issue as I have an API end point for this once authorized it is more an ...
John's user avatar
  • 121
2 votes
1 answer

Physical mechanical examples of "M-of-N" locks?

Arbitrary "M-of-N" secret-sharing protocols are a well-studied topic in cryptography, and are apparently so useful that Bitcoin Script devoted a whole opcode to them. In this blog post, I ...
Quuxplusone's user avatar
2 votes
0 answers

Why do car key remotes not use E2EE?

Background I read an article about how car keys that remotely open one's car are not secure. This answer also talks about different encryption methods being insecure. The article mentions that ...
creativecreatorormaybenot's user avatar
1 vote
2 answers

Is it possible to attack car key fobs with regular RF devices?

I hope most of the key less entry cars are using rolling codes in order to improve the security between the key fob and the car. Is it possible to intercept this communication using a device such as ...
user3496510's user avatar
  • 1,287
1 vote
1 answer

Is a Cloud-Connected Door Lock More Secure Than a Traditional Lock and Key?

Now that app based door lock replacements are getting more popular in the market, I'm wondering what the security risks are and why or why not this is more secure than an old fashioned lock with a ...
Kristian's user avatar
  • 111
1 vote
0 answers

Deadbolt will not release key easily [closed]

My car was broken into recently and its left me feeling uneasy about my security. I live in an apartment complex that is getting repaired so the traffic is heavy in and out of the building daily. The ...
Sam Benson's user avatar
1 vote
3 answers

Tricky apartment key fob copies frequency & code correctly but the copy doesn't work - not a rolling fob

I have this key fob for our apartment building, and I want to make a copy of it. I've taken it to 3 locksmiths who are able to create a copy, but the copies don't work. I've confirmed that it doesn't ...
user avatar
0 votes
0 answers

Thoughts on Vaccine Security

Are there any recommendations for the physical security of COVID-19 vaccine? I recently watched this video on covid-19 vaccine distribution. At the 0:40 ...
emory's user avatar
  • 1,580
0 votes
0 answers

When they make physical locks, do they really just make a few variations of the keys and then mix them together and sell? [duplicate]

I always assumed that each lock is unique and can only be opened with the keys it was sold with (or any copies made later from those originals). But the truth seems to be that they just make "a few" ...
Eddye Flores's user avatar
-1 votes
5 answers

Why do most cars use physical keys and no PIN?

Why do car makers rely on physical start keys, which can be stolen by home burglars and then used to start the vehicle? Why don't they use more secure methods such as a personal PIN, or a pin code to ...
Christian's user avatar
  • 265