A plug-in device or a hardware circuit can be used as keylogger tools. Either of the two can log to their internal memories all of a user’s keyboard activities without him being the wiser. This works like a tape recorder except that the recording is not based on voice but based on keystrokes. The hardware will act as a middle device that intercepts every keystroke that is struck by the user and store it to its built-in memory. The amount of keystrokes that can be stored in the keylogger will depend on the hardware’s memory. The output can then be sent or stored for accessing later on. Getting hold of the inputted keystrokes can be obtained through a program, an interface or even through an e-mail address.

Installing a hardware keylogger can be done inside the USB or PS/2 keyboard. Since the keylogger is inside the equipment, it will be difficult or impossible to detect it since its appearance cannot be distinguished from other wirings. Or, it can be designed so that it blends with the wiring or cabling system of the computer hardware. A step-by-step installation is available when you buy a keylogger from any manufacturer.

Is it possible to create one of your own? Absolutely. It will not be a piece of cake though. You’ll need some experience in electronics hardware. If you have it, your next step is to obtain the components. These could include, among others, a microcontroller, an EEPROM chip, a capacitor and a resistor. Using your knowledge in electronics, the components then can be soldered together to form the hardware schematics. Additional information on how to create a keylogger can be found at this site: http://www.keelog.com/diy.html