Tales from the Cryptology Book

January 23, 2010

So last Wednesday, I picked up this great book from my college library (down here, it’s called the ‘Resource Center (RC)’). At the risk of sounding clichéd, I’d like to point out that finding a good book in the RC is like searching for a needle in a you-know-where. But back to the book. It’s called Cryptological Mathematics, authored by Robert Edward Lewand and published by the Mathematical Association of America.

Now, I’ve been searching for a good book to get started with cryptology ever since I participated in a cryptanalysis event at last year’s Synapse. This so far, has been my best find. The style is perfect for beginners like me. But one has to have some background in algebra and number theory to better understand the encryption and decryption algorithms. OK, so I admit that not all famous ciphers have been explained. But who cares? Those are the ones that’ve been broken! The book imbibes in the reader the right spirit required for cryptanalysis… blah, blah, doopity-doop! THIS BOOK IS JUST A WHOLE LOT OF FUN!!

But maybe cryptology isn’t my thing. The very first problem from the very first problem-set from the very first chapter of the book tells me that. This is what’s been covered thus far – Mono-alphabetic substitution ciphers (Additive, Multiplicative, Affine and Keyword). So here’s the problem (rephrased in my own mundane way):

Cryptanalyze this:

KFM YGV VEM VHK AWK YZK FWG RKF MSJ JZG XOJ MEM DJZ MAM SCJ GKF EJK TSF GJI STM ZSW MKF MEJ KBS XGJ SFH PMJ JIK FME JKR MSZ

(Triple-checked, so don’t crib saying that it must’ve been mistyped)

Right before my Analog & Digital Communications lecture, that I had spent trying to decrypt this code, one of my friends had asked why they hadn’t given the keys alongwith the encrypted messages. I had laughed it off back then. Now I am forced to think along similar lines.

But don’t under-estimate me just yet. I’ve spent just over an hour with this problem (:P). I have an electronics exam coming up, which has kept my mind engaged elsewhere. So I’ve not been able to spend more time with the book. I’ll be back with (lots) more!

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