Re: A unique number for every "person" - can it be done?

john_ramsden_at_sagitta-ps.com
Date: 02/28/05 

Date: 28 Feb 2005 10:29:01 -0800

I'm curious to know why you used no-archive, as it's an interesting
problem (considered in abstract - as a practical matter it's fairly
pointless and impossible given all your constraints), but anyway ..

TGOS wrote:
>
> Calculate a number for every human being, company and organization
> on earth, that is guaranteed to be unique till the end of time.
>
> The rules in detail:
>
> 1) Every "person", real person or corporate body (like company or
> organization), needs a number. Every means every one world wide.

It's easy for individuals, apart from maybe Siamese twins: Just use
their exact GMT (no daylight saving) birth date/time, in ISO format
[Y..YY]YYYYMMDDhhmmss (with the field delimiters compressed out),
followed by the exact 10-digit zero-padded coordinates of their
place of birth, to the nearest meter, followed by its exact distance
from the centre of the Earth at the moment of birth.

Note that this is fixed-format, apart from the year being able to
expand to the left without limit.

This should work in principle even if an individual's mother was caught
short in an elevator, or airplane, or for that matter gave birth in a
space station or in a colony on Pluto!

Problems might arise if future generations develop relativistic-speed
transport, such as interplanetary cruisers, large enough to accomodate
maternity wards!

> 3) The numbers may be earth bound. The system does not have to scale
> beyond earth, in case mankind can one day life on a planet other than
> earth. But they may not be country bound.

The above takes care of that (again, in theory).

> Countries come and go, they join and separate and dissolve again.

Geologically as well as politically, on the time scales you're
considering!

> 4) The system must work without a central registry. Establishing a
> registry and saying, every "person" gets a number when registering,
> that is one higher than the last number, would work, but a central
> database like system is required.

A central "Domesday Serial Key" generator would certainly have been
the simplest solution!

> 5) Once a person has a number, he can always recover it, in case
> it got lost or forgotten, so the number creation is reproducible.

You'd have to assume a person knows their precise birth data, which
leaves abandoned babies, e.g. found on church steps, at somewhat of
a loss (unless their discovery time and place counts as their "birth"
for the purpose of constructing their Domesday Id).

> [...]
>
> 7) You may use whatever data a "person" has available, but you may
not
> private data. If you tell someone your number, he should not be able
to
> gain any non-public knowledge about you through the number.

I reckon this makes the task practically impossible, unless one simply
plays with words and says that a person's Id should be their _mother's_
exact birth time and place (or for abandoned orphans, their
discoverer's
birth details), with an extra index to uniquely identify each of her
children.

That way a person's Id says nothing about _them_ (except how many elder
siblings they had had) !

> 8) Everyone must be able to calculate his/her number, without doing a
> lot of research and it must be data everyone knows for sure (the
exact
> time of birth in ms does not qualify). On the other hand, people may
be
> forced to use a computer for doing that and have access to the
Internet.
> E.g. if you want to know the coordinates of their town of birth
(using
> whatever coordinate system you choice), this could be acceptable, as
> there could be a search engine telling people the coordinates.

Seems like you're trying to turn into something practical a problem
which in its full generality is almost open-ended, unless you assume
peoples' bodily limitations will remain moreorless what they are today
(which, if new scientific developments continue at their present rate,
is highly unlikely).

> [...]
>
> - Blood Type (consider companies have no blood type)
> - Gender (consider companies)
> - Eye color (should be constant, consider companies)

All those, and many more (including no doubt fingerprints), will
probably be capable of being changed at the drop of a hat (or pill
anyway) well within one or two hundred years let alone billions !

Turning to corporations, one's first thought is to concatenate the
ISO date/time of formation (without coordinates, as an organisation
need not be founded in one place) and the Ids, in ascending order,
of each founder member.

The snag with this approach is that individual Ids have variable
(and unlimited) lengths, and thus two different concatenated
sequences of personal Ids might in theory end up colliding.

To avoid this possibility, as someone else suggested, the best way
(although it gives impossibly long Id lengths) is to construct the
Id as a product of ascending primes 2, 3, 5, .. whose exponents are
resp the formation ISO date/time, and the Ids in ascending order of
the founder members.

Finally, to disjoin the sets of individual and corporate Domesday Ids,
as one must, I'd tack a '0' and '1' on the low-order end of each Id
in those respective sets.

Relevant Pages

  • Re: A unique number for every "person" - can it be done?
    ... > on earth, that is guaranteed to be unique till the end of time. ... their exact GMT birth date/time, ... place of birth, to the nearest meter, followed by its exact distance ... The snag with this approach is that individual Ids have variable ...
    (comp.programming)
  • Re: A unique number for every "person" - can it be done?
    ... > on earth, that is guaranteed to be unique till the end of time. ... their exact GMT birth date/time, ... place of birth, to the nearest meter, followed by its exact distance ... The snag with this approach is that individual Ids have variable ...
    (sci.math)
  • Re: GB2RS NEWS Sunday 13 April 2008
    ... I don't know your exact date of birth, ... at the time you took the RAE, and also mentioning the month and year.. ... not an exercise ICBA to do. ...
    (uk.radio.amateur)
  • Re: A unique number for every "person" - can it be done?
    ... > from the centre of the Earth at the moment of birth. ... And you know the exact second of your birth? ... and so on; and finally hash it all to 512 bit hash. ... likely a collision would be over a several thousand years and which hash ...
    (comp.programming)
  • Re: A unique number for every "person" - can it be done?
    ... > from the centre of the Earth at the moment of birth. ... And you know the exact second of your birth? ... and so on; and finally hash it all to 512 bit hash. ... likely a collision would be over a several thousand years and which hash ...
    (sci.math)
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