Idea about keys

[Dynamitejoe]

So i had this idea a few hours ago reading a book on cryptography. I was reading about how a guy named James Ellis (iirc) at GCHQ pretty much came up with secret key exchange ~10 years before anyone else. His idea came from phone networks - you could make a line secure by having the *recipient* add noise to the line, that could later be subtracted. In essence, having both parties share the burden for secrecy was essential.

I thought about all the locks and keys Ive ever seen - and realized something similar. All the locks were complex, yet ultimately passive mechanisms. All the keys that are used for locks are passive, inert bits of metal. My question is this: what would happen if we incorporate the key into the security as well? Instead of having all the security at the lock, a location ripe for intrusion, why not have the key itself *be* part of the security? Build in some kind of mechanical, optical, or electrical system that exists in the key, meaning that to open the lock is more than just the presentation of an appropriate physical device. The key and the lock ought to interact somehow, and that interaction, instead of the shape and form of the lock and key, would be the security.

I know that vending machines use an electrical current passing through the coin to determine if it is a real coin. Has anyone ever seen this done in a lock?

If we really wanted to get fancy, i'm sure there would be a way to incorporate the truly unbreakable security of quantum light polarization into a lock. He he, thats a neat idea already.

Please feed back ideas. Ill work on thinking up more stuff.

[GWiens2001]

The Cliq and the Medeco NextGen XT are both electronic keys. There are numerous others, too. But give it a try and you may come up with a new method!

Gordon

[peterwn]

Please feed back ideas. Ill work on thinking up more stuff.

I suspect there are mechanisms to remove random noise - eg to 'decode' a bugged conversation in a washroom with a tap running, similarly a local university developed a method to de-scratch old phono records. I read about this in an espionage book.

A thing to watch with 'dual locking' is to make sure a 'double compromise' is not possible. A typical setup seems to be a roughly defined mechanical masterkey system with 'bolt on' electronic access to fine tune access and to block missing keys. In one such installation, staff discovered a way to disable the 'electronic' feature which meant that any 'correct' mechanical key would open the lock even though it was supposed to be 'locked out' electronically.

[globallockytoo]

it all boils down to cost.

If electronic locks or keys can be made at comparable cost to mechanical products and offer similar long lasting attributes, perhaps electronics will take off (in the locks and keys market). But I doubt it will happen in my lifetime.

The only real benefit to electronic components in locks and keys is in audit trails and timed lockouts.

There are far too many mechanical devices that offer substantial security to the market at prices that are so good that building, maintaining and selling electronic keys and locks is simply uncompetitive and unfeasible at this time.

[jonwil]

I didn't know the "noise" crypto from Cryptonomicon (with the special phonograph records) was a real thing. Cool

My view is that if you want to go for electronic locks, they should be purely electronic (e.g. RFID/NFC cards or otherwise) and not rely on physical security at all.

[GrzyWhop33]

Here's an idea, different metals and metal alloys have different electronic resistances. How about a key and a lock that requires that certain resistance in the key to disengage a solenoid inside the lock. Or have the lock act like a metal detector and require the presence of a selected metal to be present giving off it's specific magnetic field? Just some ideas I had.

[peterwn]

Here's an idea, different metals and metal alloys have different electronic resistances. How about a key and a lock that requires that certain resistance in the key to disengage a solenoid inside the lock. Or have the lock act like a metal detector and require the presence of a selected metal to be present giving off it's specific magnetic field? Just some ideas I had.

After going to the bother of supplying a solenoid and providing a power source, you might as well use programmable chips in the lock and the key to benefit from extra flexibility. This then begs the question of why any mechanical security elements apart from the solenoid are necessary. Such cylinders are available either using physical contacts between the key and lock or RFID to couple them. Others are available with dual electronic/ mechanical security.

Having said that there was an automotive lock with a resistor contained in the key which had to be the correct value to activate the ignition.

[somenewguy]

In a very simple sense, the 'interactive' parts on some higher security keys do what you are after.

GM also had a very simple challenge/response setup in their car keys where the unknown element was just the value of a resistor in the key; the car would check that it was the correct one (there were a limited number of values) before starting.

[jonwil]

Why aren't we seeing more locks that work either like the keyfobs you have for cars (with a chip that communicates with electronics in the lock such that unless you have the right chip, it wont open) or like the swipe-cards you see in office towers? There are 1 or 2 systems like that out there but mostly that tech is used in whole-of-building systems for hotels or office towers (although I have seen swipe-card tech used at the main entrance to residential accommodation at some universities too)

Its not like the technology in either the keyfobs or the swipe-cards is somehow magic and if done right (with good crypto) it would be more secure than any mechanical key I have ever seen.

[peterwn]

[quote="jonwil"]Why aren't we seeing more locks that work either like the keyfobs you have for cars (with a chip that communicates with electronics in the lock such that unless you have the right chip, it wont open) or like the swipe-cards you see in office towers? /quote]

It comes down to economics. A mechanical lock is cheaper than a standalone electronic or hybrid electronic/mechanical lock. In many circumstances is is more economic as long as the need to re-key is not too frequent. Tolerance to lost keys comes into it. If a key is lost in circumstances where it is very unlikely to be recognized as fitting a certain lock or locks, its loss may be tolerated.

Once there is low tolerance to lost keys - ie locks are re-keyed if any related key goes missing then electronic systems then become economic. The ability of audit trails would also point to electronic security. For example in the vending industry, the cost leakage of cash or product from vending machines may well justify an electronic locking solution costing 10 times as much as mechanical locks.

Reliability also comes into it. For example heavy duty mechanical locks still seem the preference for detention purposes despite potential advantages of electronic locking such as the ability to quickly re-code locks at no cost.

[somenewguy]

Also I think many homeowners wouldn't be bothered to run an electrical source to the lock nor replace batteries frequently.