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From: Miles Elam <[email protected]>
To: [email protected]
Subject: pgcrypto docs
Date: Tue, 7 May 2013 14:08:23 -0700
Message-ID: <CAPVvHdPj5rmf294FbWi2TuEy=hSxZMNjTURESaM5zY8P_wCJMg@mail.gmail.com> (raw)
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Currently the docs show various stats on hashes per second and time needed
to find a particular key.  Unfortunately since the times are based upon a
Pentium 4 @1.5GHz, I worry that many would take the advice on that page at
face value, e.g., "more than 100/sec is too much while less than 4/sec is
too few," with a P4 in mind.

Using a first-generation Core i5 processor as a baseline, we're looking
roughly at about a 64x increase in processing power, not including any
dedicated crypto processing in hardware like their AES extensions.

The new table, simplistically adjusted by 64x is as follows.

Algorithm    Hashes/sec    For [a-z]    For [A-Za-z0-9]
--------------------------------------------
crypt-bf/8    1792    4 years    3927 years
crypt-bf/7    3648    2 years    1929 years
crypt-bf/6    7168    1 year     982 years
crypt-bf/5    13504  188 days    521 years
crypt-md5    171584    15 days    41 years
crypt-des    23221568    157.5 minutes    108 days
sha1    37774272    90 minutes    68 days
md5    150085504    22.5 minutes    17 days
--------------------------------------------

Perhaps with a more up to date dataset, users would be far less likely to
use far more turns of blowfish and be far more (read: appropriately) averse
to using schemes like md5.  After all, who wants to use a hash that can be
cracked on 2-year old mainstream consumer processors in less than half an
hour, let alone dedicated hardware with real money behind it.

Unfortunately I only have laptops, no desktops these days.  (A sign of the
times?)  So while I could re-run these benchmarks on a mobile i3, I don't
know if that is what is appropriate for this data table.

Anyway, food for thought.


Cheers,

Miles Elam


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