Secret codes

I was recently parking my car and, as I bought the ticket, observed that the machine was manufactured by a company very close to where I used to live; I knew some people who worked there. I mused upon the idea that, if I were programming the machine, I might include a “back door” access mechanism which would enable me [or anyone knowing the correct button pressing sequence] to get a ticket for free.

Of course, that would be unethical, as it could result in defrauding the company running the parking lot, but back door access to systems is not necessarily wholly bad …

When developing numerous embedded systems, I commonly found the need to include a “debug” or “service” mode, which resulted in functionality which would not normally be of use to the final user. This might include [but is not limited to] a display of internal data, generation of random data for return [in lieu of real readings from a sensor] or loop-back of a communications channel. Obviously, the needs vary widely, depending upon the nature of the embedded application.

Access to such special modes is typically by means of a specific combination or sequence of button presses. I confess that I liked the idea of being able to make a system perform some unusual functionality simply because I knew the “secret code”. Clearly this appeal is widespread, as many desktop programs and websites feature “Easter eggs”, which are additional facilities – normally of an entertaining nature – which may be accessed by means of a special keying or clicking sequence. Sometimes they are very simple – like the display of a humorous graphic – in other cases they are very complex. [Does anyone remember the flight simulator built into Excel years ago?] Sometimes special keys simply give access to useful facilities only known to the cognoscenti – such as the screen capture on an iPad.

As I have never been very interested in computer or video games, I was unaware until recently that there is a widely used, “standard” code for accessing Easter eggs. It is called the “Konami Code” and requires the user to hit a specific key/button sequence: UP, UP, DOWN, DOWN, LEFT, RIGHT, LEFT, RIGHT, B, A – this may need to be terminated with ENTER. At various times, well known sites like Google and Facebook have responded to this code. I am intrigued about where else it might be effective …