An ATM18 Passepartout

The word passepartout is of French origin meaning literally ‘pass everywhere’. A single key that can open several locks is also known as a passkey or master key. In the real world such a key would be used by a house manager of say student accommodation. Here each student’s personal key only opens their own door but the house manager’s passkey can open all of them. If the key is stolen however every door is insecure.

 

For this reason it is important that we don’t use the same password on our computer and every secure website that we visit on the Internet. Each password must be unrelated and as random as possible and under no circumstances should be written on a piece of paper and stuck under the keyboard! It’s like hiding your front door key under a flowerpot, that’s the first place burglars look. It is also important to regularly change your passwords. This means that before long we could typically have around fi fty such passwords to remember and if, as recommended we change them every month this amounts to 600 strings of meaningless random characters to memorise every year. Hands up all those who follow this advice… no I thought not. Unless you possess Rain Man’s ability of total recall you probably take a chance by using easy to remember short passwords and never bother to change them. There are some commercial solutions available on the market to help manage passwords, some good, some not so good and they are often diffi cult to use.

 

The solution suggested here requires a few components together with the ATM18-controller test board plus software which can be downloaded for free from the Elektor website. The controller generates secure passwords and sends them to the PC’s USB port; we only need to remember a short four digit PIN. All the complex calculations are performed by the microcontroller.
 

Project Code : 080950-IND1106P061