[comp.dcom.telecom] Kredit Kard Kwestions

black%ll-micro@ll-vlsi.arpa (Jerry Glomph Black) (01/24/89)

  First, a comment on the PIN brouhaha: AT&T cards (and BOC cards) always have
had your PIN number right on the card, but as it's a 4-digit number, most
people can remember it.  There are numerous ways to write down your secret code
numbers on a wallet card so as to maintain security: use 10's complement, or
subtract 1 from each digit, or you-name-it.

  I'm a bit perplexed by the 'international' number
on the bottom: 1M,<10-digit phone no.>,<1 digit>. It seems pretty easy to
guess or 'exhaustively' determine the digit for anyone, if it only takes a
maximum of 10 tries!

  A mundane question: I have a Sprint FON card. It gives the 800-877-8000
number to access the service, but no mention of a 950-1022 or whatever
the local access # is.  Do you get a cheaper rate if you avoid the 800 number?
The scanty documents which accompanied the card give no clue. Is this another
case of deviousness, or what?

JG Black, black@micro@LL-VLSI.ARPA

jimmy@ee.UCLA.EDU (Jim Gottlieb) (01/29/89)

In article <telecom-v09i0028m03@vector.UUCP>, black%ll-micro@ll-vlsi.arpa (Jerry Glomph Black) writes:
>
>  First, a comment on the PIN brouhaha: AT&T cards (and BOC cards) always have
> had your PIN number right on the card, but as it's a 4-digit number, most

I like the way New York Tel does it (I think it's the only thing I like
about them).  Their calling card has ONLY the PIN on it, at least in
cases where the first ten digits are the same as your phone number.
This makes the most sense.  You already know the first ten.  And if
someone finds the calling card, with just the PIN it's worthless to
them.


>   I'm a bit perplexed by the 'international' number
> on the bottom: 1M,<10-digit phone no.>,<1 digit>. It seems pretty easy to
> guess or 'exhaustively' determine the digit for anyone, if it only takes a
> maximum of 10 tries!

True.  It follows a check-digit system like calling cards used to.  It
_is_ rather easy to figure out (given a few different cards to look
at), but it can only be used from outside the US so the potential for
abuse is minimized.  Though I guess you _could_ hack up a similar
number for the country you wanted to call to from here.


>   A mundane question: I have a Sprint FON card. It gives the 800-877-8000
> number to access the service, but no mention of a 950-1022 or whatever

Sprint has eliminated their 950 numbers for calling card use.  It is
now only for those poor slobs without Equal Access.
--
Jim G.        E-Mail: <jimmy@denwa.uucp>  or  <jimmy@pic.ucla.edu>
^^^^^^    V-Mail: (213) 551-7702  Fax: 478-3060  The-Real-Me: 824-5454