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A manager invited me to try and test the physical security of his office door lock (by non-destructive means, i.e. not ramming the door down). I found that since the door opened from inside by a handle (which automatically unlocked the lock -- i.e. even if the door was locked, all you had to do was push the handle down from the inside to open it), and since there was a 1/2-inch gap between the bottom of the door and the floor, you could open the door by sliding a coat hanger under the door, rotating the coat hanger in order to loop a piece of wire over the door handle, and then pulling the wire from under the door in order to pull the handle downward.

OK. But I've never seen any guidelines for physical security which explicitly say that doorknobs are more secure than door handles. A Google search for "doorknobs vs door handles security" turns up nothing useful.

Have you ever seen a list of guidelines for physical security that recommends doorknobs over door handles? It seems like something that would significantly increase physical security of locked doors no cost. If a list of guidelines doesn't include this, I would consider it incomplete.

(Obviously neither does much good against a smash-and-grab attack, but the coat hanger would be useful in situations such as (a) nobody's watching you, but there are other people on the same floor who would hear you if you smash the door open, or (b) you want to avoid the break-in being detected after the fact.)

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    a) People won't like it at all; just because the key now is needed on the inside too, which takes more time. b) Because of the the importance of quick escapes in emergency situations, this is not allowed in many countries. – deviantfan Jul 30 '18 at 2:26
  • @deviantfan there are door knobs with push-buttons in the centre, or a turnable switch to lock the door which unlock when you turn the inside knob. – Οurous Jul 30 '18 at 5:20
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    Try a different search query: "door knob vs door lever" You will find that "accessibility" is an issue that can supercede security. Including this question: ux.stackexchange.com/questions/57929/… – schroeder Jul 30 '18 at 8:43
  • Please note that questions of the pattern "where is a report that says X?" is not a great fit here. Instead, ask whether the 2 different door mechanisms have a difference in security. – schroeder Jul 30 '18 at 8:46
  • Even worse than this are the motion activated sensors that unlock doors whenever someone walks by. Some idiot facilities guy put these in at an old workplace several years ago. That it until the employees got annoyed at the stairwell doors constantly unlocking when you got within 3 feet of them. They got disabled within a week. With these you could perform the same trick, but even easier (coathanger + motion). – Steve Sether Jul 30 '18 at 17:49
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I'm not sure that an official report exists, or that one would need to be written. It could be said that a lever is inherently easier to operate and more prone to accidental opening than a knob. Anyone with kids or jumpy pets can tell you that.

Another reason why one might not write a report on the security of the difference is that it might not matter because Accessibility laws might supercede any security considerations. Levers are easier to operate with a closed fist (which is one standard for accessibility).

What is strange to me in your question is that you are asking about a specific feature of that one door handle in which it automatically unlocked when used. That is certainly not a ubiquitous feature of door levers and not confined to levers. Doorknobs can do the same thing. So, in addition to the above points, you have set up a false comparison between the two styles.

You simply cannot state that levers are more or less secure than knobs because your boss' door had an automatic unlock feature. Instead, you would want to determine that a handle with an automatic unlock feature is less secure than a handle without that feature. And I do not think that you need an official report to make that conclusion.

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In the PCI-DSS specifications for physical security they make no distinction nor does the NIST 800-53 make a distinction between the two thus I would say you are fine with a lever or knob.

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