

Two Centuries On, a Cryptologist Cracks a Presidential Code - madars
http://online.wsj.com/article/SB124648494429082661.html

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js2
Submission from when this was first published -
<http://news.ycombinator.com/item?id=684023>

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ars
It's interesting how in those days being "simple to learn and memorize" was an
important part of a cipher, but not these days.

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rmc
It's because all cryptography was done (almost) by hand and most importantly
the people trying to break it were only really using metal methods. Nowadays
people use computers to break your codes, so your code has to be much more
complicated. The only way to do that is with a computer.

Codes are an arms race.

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redthrowaway
Sounds like a pretty weak cypher by todays standards. 90 million combinations
seems like it would be fairly easy to brute force. Still, it's interesting to
see that some of his ideas, like row operations on matrices, are still used in
some crypto algos today.

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ceejayoz
The article says "90 millions of millions", which is a little larger than 90
million.

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redthrowaway
Yes, but how much longer?

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Artifex
Correct me if I'm wrong, but it almost sounds like a rudimentary AES-type
encryption when they describe how he broke it into a grid and then jumbled the
lines. I'm no cryptographer, but the description of this compared to AES
encryption seemed remarkably close.

That said, using digraph probability to solve it was inspired.

