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  Please don't email my password in plaintext  (Read 1559 times)
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Offline Cero

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« Reply #30 on: 2012-01-16 17:21:24 »

sha512 hasn't shown collisions, afaik
SHA512 has 512 bits (64 bytes).

Computing all hashes from all possible unique files of 65 bytes, you will find at least 256 collisions.
Computing all hashes from all possible unique files of 66 bytes, you will find at least 65536 collisions.
Computing all hashes from all possible unique files of 67 bytes, you will find at least 16777216 collisions.

I'm no security expert.
http://en.wikipedia.org/wiki/SHA-2
Quote
SHA-2 - SHA-512/384, Collisions found: none

So I thought, with everything below SHA-2, including obviously stuff like md5, collisions have been found; therefore they are insecure.

Offline OttoMeier

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« Reply #31 on: 2012-01-16 17:23:36 »

Quote
What you need to do is salting your hash.

thats simple just use the user name.
 user name +password->hash->db  
(user name name is stored in plain text with the hashcode) in db.
I know that that sounds strange but its "secure".
Offline Riven
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« Reply #32 on: 2012-01-16 17:24:50 »

Quote
What you need to do is salting your hash.

thats simple just use the user name.
 user name +password->hash->db  
(user name name is stored in plain text with the hashcode) in db.
I know that that sounds strange but its "secure".
It doesn't sound strange, it's "obvious".

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Offline theagentd

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Posts: 1392
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« Reply #33 on: 2012-01-16 17:32:52 »

sha512 hasn't shown collisions, afaik
SHA512 has 512 bits (64 bytes).

Computing all hashes from all possible unique files of 65 bytes, you will find at least 256 collisions.
Computing all hashes from all possible unique files of 66 bytes, you will find at least 65536 collisions.
Computing all hashes from all possible unique files of 67 bytes, you will find at least 16777216 collisions.

I'm no security expert.
http://en.wikipedia.org/wiki/SHA-2
Quote
SHA-2 - SHA-512/384, Collisions found: none

So I thought, with everything below SHA-2, including obviously stuff like md5, collisions have been found; therefore they are insecure.
This should be obvious? >_> I mean, a 512-bit hash can only hold a certain number of different values (as many as a Java long), so it's obvious that 2 or more passwords longer than 64 bytes will end up with the same hash. If this wasn't the case then hashes could be used for file compression to compress any file to 64 bytes. Yaaaay.

There is no god.
Offline Riven
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« Reply #34 on: 2012-01-16 17:34:56 »

512-bit hash can only hold a certain number of different values (as many as a Java long)
Stare

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Offline Shazer2

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« Reply #35 on: 2012-01-16 17:52:38 »

Update or change to MyBB, much more secure. They are free and provide a merge tool.  Grin

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Offline ra4king

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« Reply #36 on: 2012-01-16 18:04:23 »

512-bit hash can only hold a certain number of different values (as many as a Java long)
What kind of wonky math are you doing? Grin

Offline Cero

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« Reply #37 on: 2012-01-16 18:08:44 »

file compression ?

sha are hash functions. its not RSA. you cant decrypt a hash to the original content =0

Offline ra4king

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« Reply #38 on: 2012-01-16 18:32:08 »

@Cero
He meant that if there were no collisions in SHA-512 at all, then you could be able to get the original content of any file using the hash.

Offline Shane75776

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« Reply #39 on: 2012-01-16 18:41:46 »

<OT>
@Shane75776:  Why do the (non-working) links in your signature read like they're links to malware?
</OT>
Hahaha he just failed at correctly setting up the URL tag Tongue

When you fix them, the first link gives me a 404 and the second link is to a fraud/malware "satellitedirect" site Smiley

huh thats messed up. not sure what the links are for. Must have been really old links from way back when I first
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Offline theagentd

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Posts: 1392
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« Reply #40 on: 2012-01-16 18:57:46 »

512-bit hash can only hold a certain number of different values (as many as a Java long)
What kind of wonky math are you doing? Grin
Gah! Mixing up bits and bytes... Long = 64 bits, SHA-512 = 64 bytes. >_>

There is no god.
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