On Thu, 31 Jan 2013 08:43:03 -0800 (PST),

http://www.velocityreviews.com/forums/(E-Mail Removed) wrote:

> I'm wondering if anyone can help me as I can't seem to get

> this to work. There is an online dice game that is

> provably fair by calculating the 'dice roll' using using a

> sha256 hash calculated against my transaction ID generated

> by me. The secret used to make the calculation is revealed

> at the end of each day thus allowing you to prove they

> didn't cheat. So they provide the following to allow you

> to verify the calculation of the dice roll:

>

> Secret used = r7A7clvs9waizF+6QEiI0tgAq1ar48JItK3kg9kaeAFXz2vsMs HmOd9r9fhkmtxTz3CQnGAPMaDeKLvgb1A2VA

> Secret hash sha256(r7A7clvs9waizF+6QEiI0tgAq1ar48JItK3kg9kaeAF Xz2vsMsHmOd9r9fhkmtxTz3CQnGAPMaDeKLvgb1A2VA) = 48d78d573b9b8e11a13a72d9a78011f2e5d9754d89de47b209 f32c51777f535d

> Lucky hash sha256(r7A7clvs9waizF+6QEiI0tgAq1ar48JItK3kg9kaeAF Xz2vsMsHmOd9r9fhkmtxTz3CQnGAPMaDeKLvgb1A2VA:108128 06653842663997bf5971637f86f26c71a4716276d7fa8f323a 83588d91:1) = dfa8769be81a543002865c88a5b52fa07f3b67fc7cd9b519c3 f6a6452bcd48e4

>

> Lucky Number 0x48e4 = 18660

>

> So, I'm doing the following:

>

> C:\Python27>python

> Python 2.7.3 (default, Apr 10 2012, 23:24:47) [MSC v.1500 64 bit (AMD64)] on win32

> Type "help", "copyright", "credits" or "license" for more information.

>>>> import hashlib, hmac

>>>> txid = 'r7A7clvs9waizF+6QEiI0tgAq1ar48JItK3kg9kaeAFXz2vsM sHmOd9r9fhkmtxTz3CQnGAPMaDeKLvgb1A2VA'

>>>> secret = '10812806653842663997bf5971637f86f26c71a4716276d7f a8f323a83588d91:1'
[snip]

>>> txid = 'r7A7clvs9waizF+6QEiI0tgAq1ar48JItK3kg9kaeAFXz2vsM sHmOd9r9fhkmtxTz3CQnGAPMaDeKLvgb1A2VA'

>>> secret = '10812806653842663997bf5971637f86f26c71a4716276d7f a8f323a83588d91:1'

>>> hashlib.sha256(txid+":"+secret).hexdigest()
'dfa8769be81a543002865c88a5b52fa07f3b67fc7cd9b519c 3f6a6452bcd48e4'

>>> 0x48e4
18660

>>>
.. . . which is the number you wanted, right?

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