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Message-ID: <SNT151-W902926CDE9837FF83699C5820F0@phx.gbl>
From: Andres Home <a86551@outlook.com>
To: "bitcoin-development@lists.sourceforge.net"
	<bitcoin-development@lists.sourceforge.net>
Date: Sun, 27 Oct 2013 22:25:41 +0000
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Subject: [Bitcoin-development] Advisory: PHP library Bitcoin SCI weak key
	generation
Precedence: list

For those developers who are using the Bitcoin SCI library (maybe others to=
o=2C I=0A=
found two total and could only make contact with one)=2C I would advise tha=
t you=0A=
review how your software handles private key creation.=0A=
=0A=
Up until today=2C the Bitcoin SCI library used the Mersenne Twister PRNG or=
 the=0A=
GMP library's PRNG directly to generate private keys. This has been somewha=
t =0A=
resolved in the most recent version (October 27th)=2C but only for the =0A=
createNewMiniKey() function. Even if you haven't been using this library=2C=
 it =0A=
would be a fine oportunity to check your key generation functions if you do=
 not =0A=
interface directly with bitcoind. =0A=
=0A=
Affected keys have 32bits of entropy=2C possibly up to 56bits depending on =
the =0A=
build of PHP=2C a low enough amount that would allow GPU based attacks on k=
eys=0A=
in the lower ranges.=0A=
=0A=
=0A=
I do not know how many keys have been created using either function=0A=
.=0A=
I also don't share the authors optimism that this isn't an issue. 		 	   		=
  =