As I wrote in past, I used to help Police work in specific investigations where a mix of knowledge between the military and information technology was required.
Encryption wasn’t born with computers. It is an ancient discipline and one of the best lessons of my professional life comes from a 72 years old, almost illiterate, mafia boss.
Previous investigations had shown that this person had been able to give orders to his organization when he was serving a life sentence under the strong controls provided by prison in solitary confinement rules of Italian Article 41-bis prison regime.
|General De Gaulle at BBC Radio Londres|
All people come in contact with the boss, including his lawyer, were under control, so some kind of wireless, invisible, network should be in place. We were asked to analyze the written messages to try to understand it there was a kind of secret code embedded in the few words written on paper.
It wasn’t easy. There were only 6-7 messages directed to his family with few simple sentences each sounding like “I feel good. I eat every day and sleep well. I hope the same for you”. Very simple words, nothing like WWII BBC Radio Londres coded messages.
We wasted long time and burned a couple of CPUs trying to find a code (if someone was) and only when we asked for the photocopy of the original message we had the idea that helped us to solve the case.
The messages were always photocopied before to be sent to the recipient. Even on the copy the trick was evident.
The code wasn’t in the sentences, but was in the paper itself. Different messages were folded in very different way. So, the paper was the code, not the written words. It was a very simple code. The intuition was finally confirmed by another mafia boss that has decided to collaborate with Police in order to obtain some advantages in his prison regime and duration. We didn’t really decode messages because the method was widely used by old mafia guys, but different folding meanings have been agreed only directly between sender and recipient.
On another hand, we proved that information was sent outside by a prisoner despite the Article 41-bis regime.
The lesson I received was that the primary encryption purpose is to share information without the information itself is available to the enemy. So the first rule is to put the information where the enemy is not looking for (the science of hiding messages is called steganography. Thank you +Luca Sommacal ). In the more modern way, in other investigations where I was involved, secret information were shared via email not in the text, but in the pictures attached (I’m not going to explain further for security reasons).
The bad news is that if you have few things to share and a simple hidden code, it is very difficult to find the meaning. Sometimes, as we did, you can prove that the code exists, but you can’t really read the message.
Obviously this is a bad news only if you don’t work for the dark side of the Force.