Encryption

Telegraphic Mining Code 1888

Reading about Bauxite last week, I came across an old book entitled Telegraphic Mining Code. It's the strangest thing. As you can see from the portion reproduced above, it is a list of 'words' and their associated phrases. Some of the 'words' are ordinary words, but most appear to be near random sequences of letters. That's okay, because they aren't meant to be read, but only to be used as an index into the code book. The list of code words runs over 300 pages, and I pity the poor souls who had to make use of it. I suspect the purpose was to conceal your activities from your competitors. This would only work if they did not have a copy of the book. I suppose it is like any new technology. The first ones to adopt it have a leg up on the competition. I wonder how long it was before it became obsolete?

Today we have a video about hacking garage door openers.


This Toy Can Open Any Garage
Apparently Derek's garage door openers date from the dawn of the digital age, their encryption-fu is weak. Modern openers use a rolling code. Each time a signal is sent, a new code is generated from the previous code. The problem here, that the video does not adequately explain, is how the receiver and the transmitter stay in sync. Wikipedia tells us that "A typical implementation compares within the next 256 codes in case receiver missed some transmitted keypresses." Okay, but what happens when your kid gets hold of the remote and presses the button a zillion times? 256 codes are not going to cover it. I suppose you could use a longer list of numbers, and given the size of the numbers, it would not affect the security. I mean, how many times can a kid press the button before he gets bored?