1994-09-23 - Re: Fast Modular Factorial?

Header Data

From: Hal <hfinney@shell.portal.com>
To: cypherpunks@toad.com
Message Hash: a0593fd358af82bd0e52506850c67dcfa9c3235d9e9278d25fc78deff731c858
Message ID: <199409232305.QAA13709@jobe.shell.portal.com>
Reply To: N/A
UTC Datetime: 1994-09-23 23:06:09 UTC
Raw Date: Fri, 23 Sep 94 16:06:09 PDT

Raw message

From: Hal <hfinney@shell.portal.com>
Date: Fri, 23 Sep 94 16:06:09 PDT
To: cypherpunks@toad.com
Subject: Re: Fast Modular Factorial?
Message-ID: <199409232305.QAA13709@jobe.shell.portal.com>
MIME-Version: 1.0
Content-Type: text/plain


I find that for the numbers I have tried, that (p-1)! mod p = (p-1) if
p is prime, else it equals 0, with one exception (p=4).  So if this
is true (probably a standard result; it sounds familiar) then it might
actually be easier to find the factorial of a larger number mod a
prime than a smaller one.
Hal

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• 1994-09-23 (Fri, 23 Sep 94 16:06:09 PDT) - Re: Fast Modular Factorial? - Hal <hfinney@shell.portal.com>
  • 1994-09-24 (Fri, 23 Sep 94 17:07:53 PDT) - Re: Fast Modular Factorial? - chen@intuit.com (Mark Chen)