From: Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: [PATCH v2 1/4] siphash: add cryptographically secure hashtable
 function
Date: Thu, 15 Dec 2016 15:57:46 +0800
Message-ID: <20161215075746.GA14699@gondor.apana.org.au>
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To: "Jason A. Donenfeld" <Jason@zx2c4.com>
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Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> 
> Siphash needs a random secret key, yes. The point is that the hash
> function remains secure so long as the secret key is kept secret.
> Other functions can't make the same guarantee, and so nervous periodic
> key rotation is necessary, but in most cases nothing is done, and so
> things just leak over time.

Actually those users that use rhashtable now have a much more
sophisticated defence against these attacks, dyanmic rehashing
when bucket length exceeds a preset limit.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt