Comments on: Adding a keypad to a key card lock

By: eliza

eliza — Mon, 14 Dec 2009 11:29:27 +0000

Great Post…….Thanks for sharing the information….

By: jproach

jproach — Sat, 10 Oct 2009 06:43:57 +0000

@andrew: looks like it just winds for a certain period of time and then stalls once its reached the open position. The handle is spring loaded which allows it to return to the start position when power is removed. Simple and effective.

If your interested in positioning, it could be done with various types of limit switches or rotary encoders.

By: Michael

Michael — Fri, 09 Oct 2009 23:41:51 +0000

It’s great until someone comes along and cuts that little ribbon cable that wraps around behind the door. Then you’re not getting into your room at all. Brilliant!

By: jc

jc — Fri, 09 Oct 2009 20:07:19 +0000

Yes, but a cellphone or anything else except something that you can carry in your head is something you have to have on your person. The point is NOT to have to carry anything to get in. Unless you’re totally trashed, it’s unlikely you’ll forget your PIN.

Many new cellphones, especially those in Europe and Japan are coming with iClass 13.56Mhz Prox capability built in. Then rather than carrying a card, you can present your cellphone to the lock to get in, make purchases, etc. Kinda neat, kinda scary. Unless you’ve got an additional layer of a PIN or biometric, someone just has to snatch your cellphone to gain access.

And while I don’t know if anyone has broken the encryption that iClass Prox offers, someone has built a Prox sniffer that’s capable of both 125Khz eProx and 13.56Mhz iClass Prox. Some very rudimentary access control systems use nothing but the very card ID, which is basically the public half of the encryption key. So it’s easy enough to sniff and reproduce eProx and card ID-only iClass stuff.

@Sklyer, your Arduino system is easy enough to make impractical that it’s not worth bothering with. 8 digit keys with increasing delay times between bad entries will give such a wide number space over such a long period of time that someone is going to see you sitting trying. You’d be better off burying a video cam in the ceiling, or trying a high-voltage pulse approach.

One thing to remember about access control systems: From MOST people’s perspective, it’s to keep unauthorized people from getting in. But a denial of access attack is pretty effective, too. Don’t want to go to class? Get there first and break the lock on the lecture theater so NO-ONE can get in. Or keep the president of the company out of his office. All sorts of effective mayhem can be committed by keeping authorized people out, instead of just the unauthorized.

By: Insteon

Insteon — Fri, 09 Oct 2009 19:43:47 +0000

It’s neat, and for a drunk college student who probably loses everything on him it may work well, but I can’t help thinking something bluetooth related or otherwise accessible via your cell phone would be a better plan. Have your phone, get into your room, easy.

By: nave.notnilc

nave.notnilc — Fri, 09 Oct 2009 19:21:51 +0000

yeah, let’s get the [read] thingie back :p

By: andrew

andrew — Fri, 09 Oct 2009 19:10:02 +0000

How does he make sure the motor doesn’t wind too much? Also, what makes sure it resets back to the right position?

By: Skyler

Skyler — Fri, 09 Oct 2009 17:19:11 +0000

And then someone annoying like me comes along, taps into the *exposed* wiring, and brute-forces the combination with an Ardiuno. :P

By: cirictech

cirictech — Fri, 09 Oct 2009 17:14:05 +0000

I like the duck tape, I was going to do something similar when I lived in a dorm but the paint on our doors was to old and tape would peal it right off and that meant a fine. would be cool if it could actually lock/unlock the door, not just open the handle. all together not bad.

By: orlando custom home builder

orlando custom home builder — Fri, 09 Oct 2009 16:58:42 +0000

Nice idea! But I would probably only use it in the insistence where I forgot my card and not as a full-time key.

By: JohnQSecurity

JohnQSecurity — Fri, 09 Oct 2009 16:38:42 +0000

This is far from secure. It’s probably MUCH more easy for him to punch in the code than it is to slide his card. Problem is that over time, the key pad will wear thus revealing which numbers are used for the combination. I will be willing to bet you that if he does change his combination, that it’s not frequent enough.

By: andrew

andrew — Fri, 09 Oct 2009 16:08:23 +0000

I’m glad we brought this up. I have missed the “read” link since the day they removed it.

By: penleeki

penleeki — Fri, 09 Oct 2009 16:06:23 +0000

A friend of mine had a professional system like this. They were having trouble programming in new passwords and I went in to help out. It was similar to this but with a crucial difference. The entire device was mounted on the outside, the screws were on the front, and it was fed the buzzer wire. Once the front was unscrewed you could reset the master password if it took your fancy, or just short the buzzer wire.

I like how his dormitory is more secure than my friends office was.

By: jc

jc — Fri, 09 Oct 2009 15:58:22 +0000

Sorry, I saw that link, and didn’t realize it was the actual article. Probably because of my intense dislike for Instructables (a great idea gone horribly wrong).

If that’s the lock I think it is, that’s made by a sister company of ours. We make locks for all markets, which have various options for Prox, mag card, keypads, and some which have WiFi and Ethernet access (although the networked locks aren’t intended so much for dorm rooms). We don’t do biometrics yet because they’re somewhat insecure, and don’t lend themselves to the power requirements of universities that only want to replace batteries at most once a year, and preferably every two years.

By: Addictronics

Addictronics — Fri, 09 Oct 2009 15:43:21 +0000

@jc I know, ever since the “read” link has been removed I have had to hunt for it. Could we please have it back? Thanks

Sms would be neat, i always thought the secret knock would be very insecure, and i really like the usb thumbdrive authentication.