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In the Blue Midnight Wish (BMW) cryptographic hash function, is there a variable I can use to increase memory/CPU resource consumption to slow down the password hashing process? Call me crazy, but I really like BMW and I'd like to use it to hash passwords. It's obscure, so a bit better, but I am also paranoid, so I need to increase hashing time.

TildalWave
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user1757922
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    When it comes to cryptography, "`obscure`" != "`better`". In fact, for most values, they are opposites. – AviD Apr 16 '14 at 07:33
  • I like obscure hashes. Don't blame me... Plus, I never let a hash be without a common hash, and I never let a hash without a obscure hashes (usually a few) – user1757922 Apr 23 '14 at 02:35

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You don't increase hash time (I surmise it is for hashing passwords) by tuning the hash function from within -- especially one which has been optimized to be very fast. You get slow hash time by integrating the hash function in a larger structure which runs many iterations. In any case you would not want a slowdown by a factor of 2 or 3, rather 200000.

See this answer for a primer on hashing passwords. See this site for an ongoing open competition to design better password hashing functions.

Community
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Thomas Pornin
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  • Okay, but I don't like FGPAs. I really really don't. CPUs have (compared to a FGPA) alot of memory avalible. FGPAs don't. Is there a way to Increase memory? – user1757922 Apr 15 '14 at 22:28
  • @user1757922 You can connect a ram chip to a FPGA. Just like how you attach a ram chip to a CPU. CPUs only have 1-8 meg of on-board ram. Just because you don't like FPGAs does not mean that a cracker doesen't. Sorry. – DarcyThomas Aug 10 '14 at 03:53