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Re: [Hipsec] HIT collision probability

Robert Moskowitz <rgm@htt-consult.com> Mon, 05 May 2014 16:59 UTC

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Date: Mon, 05 May 2014 12:59:10 -0400
From: Robert Moskowitz <rgm@htt-consult.com>
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To: Paul Lambert <paul@marvell.com>, hip WG <hipsec@ietf.org>
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Subject: Re: [Hipsec] HIT collision probability
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On 05/05/2014 12:38 PM, Paul Lambert wrote:
> http://en.wikipedia.org/wiki/Birthday_problem

Thanks. I can see I will find the math I need for the HITv2 hash which is

128 - prefix - flag = 128 - 28 - 4 = 96 bits.

>
>
>
>
> On 5/4/14, 8:40 AM, "Robert Moskowitz" <rgm@htt-consult.com> wrote:
>
>> What population of HIs is needed for a 1%, 10%, 50% probability of a HIT
>> collision?
>>
>> I had the math once (like back in '99 or '00) and can't find it
>> (probably did not survive the Eudora to Thunderbird migration). Thought
>> I actually had this in a very early draft, but could not find any such
>> beast.  Of course that would have been for HIPv1 HITs, not HIPv2.
>>
>> Any help on the math would be appreciated.  Also does it change with PK
>> algorithm or key length?  (seems not to me).
>>
>>
>> thanks
>>
>>
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