Date: Tue, 1 Aug 2006 22:38:16 -0300 (ADT) From: User Freebsd <freebsd@hub.org> To: Nikolas Britton <nikolas.britton@gmail.com> Cc: Robert Huff <roberthuff@rcn.com>, Xiao-Yong Jin <xj2106@columbia.edu>, freebsd-questions@freebsd.org Subject: Re: Gotta start somewhere ... how many of us are really out there? Message-ID: <20060801223754.U27679@ganymede.hub.org> In-Reply-To: <ef10de9a0608011037w3609b5a6k1709aea61d43ed0f@mail.gmail.com> References: <20060728164526.E27679@ganymede.hub.org> <20060730233839.I27679@ganymede.hub.org> <44CDAA98.3030702@freebsd.org> <44CDE02F.4090604@dial.pipex.com> <44CE7DD0.9070902@childeric.freeserve.co.uk> <871ws1v261.fsf@photon.homelinux.org> <20060731220830.B27679@ganymede.hub.org> <ef10de9a0608010121j154c7ael7ece0997a479572e@mail.gmail.com> <20060801120058.O27679@ganymede.hub.org> <17615.30414.314802.792740@jerusalem.litteratus.org> <ef10de9a0608011037w3609b5a6k1709aea61d43ed0f@mail.gmail.com>
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On Tue, 1 Aug 2006, Nikolas Britton wrote:
> On 8/1/06, Robert Huff <roberthuff@rcn.com> wrote:
>> User Freebsd writes:
>> > Actually, using ifconfig wouldn't work ... it would give unique, but as
>> > soon as you add another IP (ie. alias), the ID would change ... you'd
>> need
>> > to do something like:
>> >
>> > ifconfig | grep ether | sha256 | md5
>> >
>> > since the 'ether' would never change ...
>>
>> At least some cards (+ FreeBSD drivers) allow you to set the
>> MAC address ....
>>
>>
>>
>
> You still don't get it! Maybe this simple perl program will illustrate
> the problem:
>
> my $number = "100000000000000000000";
> my $randomkey = "";
> while (0 == 0) {
> $randomkey = `echo $number | md5`;
> print "fetch http://www.hub.org/freebsd_stats.php?HOSTID=$randomkey";
> $number++
> }
>
> Also by using only the mac address output of ifconfig you have limited
> the pool of unique keys to 16^12 (281,474,976,710,656)!!! All I need
> to do to find your mac address is compute all possible mac address
> combinations into MD5 and then just simply match it up with yours.
> Anonymity only works if the input is large then the output!!! Because
> it's computationally impossible to compute all values of a 500+ byte
> string etc. etc. The MD5 string maps back to at least (how do you
> compute the collisions?) two SHA256 keys and the SHA256 maps back to
> at least two ifconfig strings.
Thing is, we aren't so much looking for anonymity as we are uniqueness,
but, wouldn't the CPU serial id not be both?
>
----
Marc G. Fournier Hub.Org Networking Services (http://www.hub.org)
Email . scrappy@hub.org MSN . scrappy@hub.org
Yahoo . yscrappy Skype: hub.org ICQ . 7615664
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