Keypad readers present huge risks to even the best access systems. If deployed improperly, keypads let people through locked doors almost as if they were unlocked.
However, despite the drawbacks, keypads are still one of the most common choices in access today.
With this note, we examine the weaknesses of keypads including:
PIN Sharing is Easy
Inside we offer advice on how to deploy them securely and examine a type of keypad that overcomes glaring weaknesses.
The function of keypads in access control is simple. A door or gate remains locked until the user enters a valid combination string into a nearby number pad, usually a sequence of numbers.
Most access control applications assign each user their own number, called Personal Identification Number (PIN). Unless the user enters a valid combination, the opening remains locked.
Why Use Keypads?
If these input readers are so terrible, why do people use them? The single biggest 'pro' in using keypads is that no external credential is required. There are no cards or fobs to buy, fingerprints to enroll, and template records to manage. A user is given an access code that is presumably memorized or included in other documents, and nothing else is required.
The lack of external credentials results in a lower operating cost relative to 'credential-based' systems.
Despite being one of the oldest and most used access readers, keypads have huge vulnerabilities. Worse still, it takes no special tools or skills to exploit these problems. While individual units may be better, or even worse, than others at these shortcomings, the biggest problems are:
PIN Sharing is Easy
In the sections below, we examine these issues and address how they undermine even the best access control platform and most secure locks.
Is the industry differentiating units with the main relay controlling the door strike on the outside, unsecured side of the wall versus models with tethered relays on the secured inside wall? Or the control board mounted inside and just the keypad is tethered outside.
The HID Signo mullion reader keypad is probably one of HID's best new products they have come up with in years. I can remember searching high and low for a good mullion reader that wasn't a stand alone reader.
I'm not a fan of keypad locks if they are integrated into an access control system. Might as well use a badge. If there is a standalone keypad because it was an afterthought and is extremely costly or impossible to get a wire to, I can understand the need for one, but it would be a much simpler keypad programmable at the door instead of at a computer.
I'm very happy to see that multifactor authentication was mentioned in this. In a previous life, I managed physical security of a high security site. In the first year, we moved away from single-factor authentication keypads to multifactor. As stated above, it is just too easy for anyone to guess a pin code, especially if you have a large number of employees. Even with multifactor authentication, we took it a step further to mitigate the "ease of access" or convenience factor since multifactor authentication now required a card swipe and pin. No obvious pin numbers, such as 1234 or 1111, etc. Though it was a pain to initially manage, once all employees were brought on board, it made things much more secure. Something to also consider is utilizing access denied codes within your ACM when 2 or more incorrect codes are punched back to back. Granted this would be for high security sites with physical security managing and watching the ACM.