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Mar 4th, 2004

Md5 - Wtf?

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I've been looking at the text written by professor Rivest, and I REALLY do not understand the MD5 algorithm.

It produces a 32 bit encryption.. so its 32 characters, no matter what. But you can hash a string with an unlimited amount of characters... But if you do the math, only 9,472,710,129,612,967,086,019,848,437,700,000,000 possible combinations of alphanumeric characters in a 32 bit (character) hash is possible. So how can it account for the rest of the combinations of letters and numbers that you can encrypt?

Quote ...

Math Equation for possible strings produced by MD5: 32! * 36

That being "(32 x 31 x 30 x 29 x 28 x 27 x 26 x 25 x 24 x 23 x 22 x 21 x 20 x 19 x 18 x 17 x 16 x 15 x 14 x 13 x 12 x 11 x 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1) * (26 + 10)". 26 letters (A-Z) and 10 numbers (0-9) producable by MD5.

WTF?

rixius

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Mar 4th, 2004

Re: Md5 - Wtf?

You forgot to include (a-z) for a total of 52 letters.

TheOgre

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Mar 5th, 2004

Re: Md5 - Wtf?

Well.. I just used a-z generically, I didn't know they could be cap'd or not. I thought it just produced them in lowercase.

rixius

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Mar 5th, 2004

Re: Md5 - Wtf?

It only produces letters in lowercase, but it uses uppercase letters as part of the algorithm.

TheOgre

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Posting Whiz

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Mar 5th, 2004

Re: Md5 - Wtf?

It's NOT encryption. It's a hash. That means that it's not mathematically possible to decrypt an md5() encoded string. MD5() is designed to be a secure way of storting data for authentication, not for encryption. So, yes, a few times the same hash will come up for more than one string. But it's highly unlikely that you'll find more than one, and they would have to be so drastically different that they'd never be used in the same context anyway.

Roberdin

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Supreme Evil Overlord

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Mar 5th, 2004

Re: Md5 - Wtf?

Ahh okay. I'm new to this sort of thing,

Thanks for making it more clear to me.

rixius

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Mar 26th, 2004

Re: Md5 - Wtf?

I made a program that implemented the MD5 hash for files if you would like to view it?

BountyX

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Oct 6th, 2004

Re: Md5 - Wtf?

Quote originally posted by rixius ...

only 9,472,710,129,612,967,086,019,848,437,700,000,000 possible combinations...

lmao.

Might I just bring this down to earth a bit and ask if you don't think that many bafrickingzillion possible distinct hashes will be ENOUGH??

Nuez_Jr

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Dec 13th, 2006

Re: Md5 - Wtf?

Click to Expand / Collapse Quote originally posted by Nuez_Jr ...

lmao.

Might I just bring this down to earth a bit and ask if you don't think that many bafrickingzillion possible distinct hashes will be ENOUGH??

and I'd like to see him store that number in an integer:mrgreen:

Ancient Dragon

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Dec 15th, 2006

Re: Md5 - Wtf?

Click to Expand / Collapse Quote originally posted by Ancient Dragon ...

and I'd like to see him store that number in an integer:mrgreen:

You'd need a plugin module like BigfrickinNum from CodefrackingSpace.foo

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