Nitpicking:
Not for numbers issued recently.
Continuing the hijack about Luhn’s algorithm …
It’s not obvious to me that is true. I was not able to locate any cite saying the distribution of check digits was inherently uneven. Strictly speaking, absence of evidence is not evidence of absence, but for something as well-studied & documented as Luhn’s, you’d expect a limitation like that to appear somewhere, if not everywhere.
Intuitively, we’re just summing a bunch of digits in a way that prevents Benford’s law from taking hold. And then 10-inverting the final (not leading) digit of the resulting sum. ISTM that assuming a random distribution of digits in the input you’d get a random distribution in the output.
If you have a contrary cite I’m all eyes.
Last post on this way-off-subject hijack. Our ID numbers contain a YYYYMMDD birthdate as the first 6 digits, a number that indicates birth gender, a number that used to indicate “race” and other data. The checksum cannot be random, as it depends on these non-random numbers.
Mine is 7603076256084 (note, this is absolutely useless for identity theft, I have no worries sharing it)
First six digits are my birth date. The next four indicate my gender and birth registration order, the next indicates my citizenship status (birth or naturalised), the next is my race (now everyone gets an 8) and a checksum
There is not enough unique data in there to create an even spread of odd and even numbers. It boils down to the four digits indicating gender/registration which is not random , as the birth date will be heavily skewed towards summer in the Southern Hemisphere. (Including the “short month February”)
Sorry for continuing this hijack, I will really try hard not to keep on it
Further nitpicking. You can tell where they lived when they applied for their SSN. In the old days, we didn’t get them at birth.
Moderating:
Time to stop the hijack on the numbering system. Thanks.
The company I retired from started using ssn’s for employee ids in the 1970s when they computerized personnel/payroll data. That lasted for decades before someone said “Hey, wait a minute…” I believe that was in 1994-5.
Sorry @Aspenglow !
Moderating:
I think this thread is done.