Encryption

[The Evil Tin Tin]

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[Galen of Edgewood]

Originally posted by The Evil Tin Tin:
Does anyone have any links on how to build a data encryption algorithm??? Any help would be much appreciated! I am currentley attempting to build one, and struggling to find resources or module librarys.
Cheers
Tin Tin

I'm pretty sure that most of the current data encryption algorithms are held quite secretive, and the older ones are busted.

I have no idea of where to start looking. Have you done a search through Google yet?

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Dragon of the OC Crusaders

The race is not always to the swift, nor the battle to the strong, but that's the way to bet.
-- Damon Runyon

[The Evil Tin Tin]

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[Strogian]

Maybe you could take a look at some OpenSSH stuff.

[rollingrock]

This is just off the top of my head but, you could come up with an ordered list of distinct prime numbers the same length of as your message for a key then assign a number to each letter / char that would be in a message. Then calculate p1 ^ x1 * p2 ^x2 * ... where pi is the ith prime in your key (the list) and xi is the code number assigned to the ith character in the message.

Decryption would then be simple with the key since prime factorizations are unique. At the same time it is an NP-complete problem to attempt this without the key.

This particular method probably isnt very practical for reasonable length messages since you would require a looong list of primes to ensure that you could encrypt it. But, from what I understand about crypto this is how most algorithms generally work -- relying on prime factorization.

EDIT -- Not to mention the fact that the encrypted message grows faster than O(N!)

[This message has been edited by rollingrock (edited November 09, 2001).]

EDIT -- lol nevermind I just reread your message I thought you were asking how they worked Try www.gnupg.org -- the source might give you some ideas.

[This message has been edited by rollingrock (edited November 09, 2001).]

[The Evil Tin Tin]

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[rollingrock]

IT'S ALIVE! IT'S ALIVEEEE!!!

You'd better watch out man, once the NSA finds out that you implemented it there's trouble to be had. It'll be just like Sneakers except without Robert Redford and a universal decryption algorithm. All I need to do now is come up with an algorithm to factor numbers in linear time and we're set for some wacky adventures involving answering machines and temperature sensitive security systems (not to mention a cameo by James Earl Jones). But, I digress.

You might want to try talking to some of the people involved with GnuPG, I'm sure they could help you out. It's all open source too, so it could give you some ideas.

I'm happy that the "algorithm" works though :-)

[The Evil Tin Tin]

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[schnarf283]

This is a very simple XORing algorithm, and is easily broken. Let's take the string "encrypt this" and the key "abcd". First, repeat "abcd" to strlen("encrypt this"). We've now got "abcdabcdabcd". Then, loop from 0 to strlen("encrypt this")-1. Each char, the result is string[i] ^ keylong[i];. The ^ operator is XOR, not power. That's basically it. To decrypt, do the same process, but with the result rather than "encrypt this", and you will get the original string.

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Specs:
Computer 1
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PII 450mHz
128 MB SDRAM
14.4 and 75.5 GB 7200 RPM Hard Drives
Riva TNT w/ 16 MB Video RAM
Windows 98/Slackware 8.0

Computer 2
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PI 200mHz
32 MB SDRAM
3 GB 2400 RPM Hard Drive
Matrox Something or Other
Slackware 8.0, kernel 2.4.5

[The Evil Tin Tin]

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[Gomez Addams]

Have a look at this page. They have several candidates to choose from.

[The Evil Tin Tin]

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[hobbes2112]

Thanks Gomez,

I am working on a similar project.

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"Sometimes it is entirely appropriate to kill a fly with a sledge-hammer!"
-MAJ. HOLDREDGE USMC

Why Yes! I am a proud member of the SF Linux Hippy Club.

[hobbes2112]

here is a good one I found:
http://www.counterpane.com/hotlist.html

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"Sometimes it is entirely appropriate to kill a fly with a sledge-hammer!"
-MAJ. HOLDREDGE USMC

Why Yes! I am a proud member of the SF Linux Hippy Club.

[The Evil Tin Tin]

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