note 81387 deleted from function.md5 by joey

From: Date: Sun, 17 Jul 2011 08:40:12 +0000
Subject: note 81387 deleted from function.md5 by joey
References: 1  Groups: php.notes 
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Note Submitter: nathan ---- I think the suggestion to double-hash your password is not a good idea. You are much much better off adding a variable salt to passwords before hashing (such as the username or other field that is dissimilar for every account). Double hashing is *worse* security than a regular hash. What you're actually doing is taking some input $passwd, converting it to a string of exactly 32 characters containing only the characters [0-9][A-F], and then hashing *that*. You have just *greatly* increased the odds of a hash collision (ie. the odds that I can guess a phrase that will hash to the same value as your password). sha1(md5($pass)) makes even less sense, since you're feeding in 128-bits of information to generate a 256-bit hash, so 50% of the resulting data is redundant. You have not increased security at all. The wikipedia article linked in the last post advocates using a salt. No where (that I see) does it advocate using the double hash approach.

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