Why Are ATM Keypads Made of Metal?

ATM machines typically have metal numeric keypads, and here's why: when you press a key, the temperature of the keypad changes because of the heat from your fingers. If someone were to use a thermal camera right after you enter your PIN, they could potentially capture the heat from your fingers and figure out the sequence of numbers you pressed.

Why metal keypads?

• High conductivity: Metal conducts heat well and adjusts quickly to temperature changes.

• Prevents thermal imaging: The rapid temperature changes on a metal keypad make it hard for a thermal camera to capture a clear pattern, so it’s much harder to track your PIN based on thermal images.

Have you ever noticed the small cylindrical objects on things like Power cords, Mice, Keypads, Laptops and Printers?

These little bumps are called ferrite beads or ferrite chokes, and they serve a very important function: reducing electromagnetic interference (EMI) and radio frequency interference (RFI).

Why are they needed?

• Cables as antennas: When two electronic devices are connected by a cable, that cable can act like an antenna. Like any antenna, it can pick up signals from other devices, causing noise or interference.

• Ferrite beads as filters: These beads reduce the unwanted signals or "noise," ensuring that the cable doesn’t transmit any unnecessary interference.

How do they work?

• Inside these little bumps is a cylindrical piece of ferrite, a material made from iron oxide (rust) mixed with other metals.

• Ferrite is magnetic and has the ability to absorb and filter out unwanted electromagnetic signals, ensuring your ATM metal keypad work without disruption.