Winning
It's public now that I've won a Galaxy Nexus phone and a Matt Gaffney Pen and Pencil set. Yay! Some time soon I will actually have those prizes. (Although the Nexus challenge specified a ludicrously long time in which to deliver the prize, probably because the particular phone variant being awarded has not been released yet.)
I wanted to write about the nexus challenge. I had to decode this message. I saw the whole repeated word PNMQ, and a recurring pattern of Xs with one letter between them, so it seemed sure to be one of the common cipher types. Unlike some of these, the hint telling you what kind of cipher it was came only hours later.
Since it was a speed contest, I plugged it in Decrypto first, which couldn't do anything with it. Not a straight substitution. A Vigenere solver that matches on trying to guess the length by letter frequencies didn't give anything useful.
So I considered Playfair. For this, I found a tool online that let me interactively modify the key and see what my result was. The PNMQs were aligned to pair boundaries, good. After some playing around with it, I decided that the first word looked like congratulations, a reasonable start to a message like this, so I worked on modifying the key until I could make it say that. The rest fell right out.
Apparently, the colored letters were supposed to hint us by telling which letters represented letters in GOOGLE in the plaintext. A nice idea, but just not something I thought of quickly.
I wanted to write about the nexus challenge. I had to decode this message. I saw the whole repeated word PNMQ, and a recurring pattern of Xs with one letter between them, so it seemed sure to be one of the common cipher types. Unlike some of these, the hint telling you what kind of cipher it was came only hours later.
Since it was a speed contest, I plugged it in Decrypto first, which couldn't do anything with it. Not a straight substitution. A Vigenere solver that matches on trying to guess the length by letter frequencies didn't give anything useful.
So I considered Playfair. For this, I found a tool online that let me interactively modify the key and see what my result was. The PNMQs were aligned to pair boundaries, good. After some playing around with it, I decided that the first word looked like congratulations, a reasonable start to a message like this, so I worked on modifying the key until I could make it say that. The rest fell right out.
Apparently, the colored letters were supposed to hint us by telling which letters represented letters in GOOGLE in the plaintext. A nice idea, but just not something I thought of quickly.