What techniques do you use when writing your own c

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Closed 7 years ago.

For years, maybe 10, I've been fascinated with cryptography. I read a book about XOR bit-based encryption, and have been hooked ever since thing.

I guess it's more fair to say that I'm fascinated by those who can break various encryption methods, but I digress.

To the point -- what methods do you use when writing cryptography? Is obfuscation good in cryptography?

I use two key-based XOR encryption, various hashing techniques (SHA1) on the keys, and simple things such as reversing strings here and there, etc.

I'm interested to see what others think of and try when writing a not-so-out-of-the-box encryption method. Also -- any info on how the pros go about "breaking" various cryptography techniques would be interesting as well.

To clarify -- I have no desire to use this in any production code, or any code of mine for that matter. I'm interesting in learning how it works through toying around, not reinventing the wheel. :)

Ian

Answer 1

Do the exercises here:

http://www.schneier.com/crypto-gram-9910.html#SoYouWanttobeaCryptographer

For starters, look at the cube attack paper (http://eprint.iacr.org/2008/385) and try breaking some algorithms with it. After you are familiar with breaking cryptographic schemes, you'll become better at creating them.

As far as production code goes, I'll repeat what has already been said: just use what's available in the market, since all the mainstream schemes have already gone through multiple rounds of cryptanalysis.