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# Re: randomly generate unique key

From: Joan Hsieh <joan.hsieh_at_tufts.edu>
Date: Mon, 02 Jun 2003 07:59:39 -0800
Message-ID: <F001.005A82A0.20030602075939@fatcity.com>

Hi Folks,

Many thanks to Dennis, Raj, Mark and Roy. We are in the processing to evaluate which method would be better to use in our case. Personally I am very interested in Dennis's solution.

Thanks again,

Joan

DENNIS WILLIAMS wrote:
>
> Joan
> Okay, a coworker has experience in this area and provided an education on
> this that may benefit me some day. He wants 50% royalty.
>
> - Add a check digit to your existing number. This will be an easy solution
> for you, not requiring much change. The extra digit will foil someone just
> trying to create their own number by simply incrementing an existing number.
> - Here is a simple formula for your check digit. You may choose something
> simpler or more bulletproof.
>
> Let's say my original number is 123456789.
> First, I multiply each digit by a weight. Let's say my weight is 137. So I
> multiply each digit as follows:
>
> 1 2 3 4 5 6 7 8 9 (original number)
> 1 3 7 1 3 7 1 3 7 (weight)
> 1 6 21 4 15 42 7 24 63 (product)
>
> Now, add each of the digits of the product
>
> 1+6+2+1+4+1+5+4+2+7+2+4+6+3 = 48
>
> Now we use a mod operation on the result (48). Usually this is 10 or 11. If
> we chose mod 10, then our check digit is 8. So our new number is 1234567898.
>
> Dennis Williams
> DBA, 80%OCP, 100% DBA
> Lifetouch, Inc.
> dwilliams_at_lifetouch.com
>
> -----Original Message-----
> Sent: Friday, May 30, 2003 10:45 AM
> To: Multiple recipients of list ORACLE-L
>
> Hi List,
>
> Originally, Our next generate directory group use sequence # to generate
> a unique key. (we can't use emplid or social s # as key, since students
> doesn't have emplid and some foreign students doesn't have ssn). That
> works fine until the policy changed, they need to publish the unique key
> which is trunk id. According to the developers, if publish those
> sequenced unique key, it will create some problems, since the community
> can guess the next sequence # and got unnecessary info associated with
> it. Now the question is how to create a random unique key? The idea is
> create a function call combine the 3 components (date, time, MAC
> address) to generate a random #. Does the date/time (client query system
> time)can always be unique or can be duplicated? Does someone has any
> idea or experience to generate those randomly unique key?
>
> Any info would be helpful.
>
>
> Joan
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: Joan Hsieh
> INET: joan.hsieh_at_tufts.edu
>
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> Author: DENNIS WILLIAMS
> INET: DWILLIAMS_at_LIFETOUCH.COM
>
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```--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: Joan Hsieh
INET: joan.hsieh_at_tufts.edu

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
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To REMOVE yourself from this mailing list, send an E-Mail message
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Received on Mon Jun 02 2003 - 10:59:39 CDT

Original text of this message

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