c186aj@cory.berkeley.edu (Steve Forrette) (02/04/90)
When I requested a calling card from U S West about a year ago, I was told that I was free to choose my own PIN, as long as it didn't start with a 0 or a 1. This being the case, I don't see how there could possibly a checksum scheme. When I got the card, it indeed had my 10 digit number followed by my chosen PIN. As far as PIN sharing goes, here's what I've determined from talking to AT&T and BOC representatives: When you request a card from AT&T, they send a request to your BOC for your PIN. If you already have a BOC card, its PIN is given to AT&T. If you don't, the BOC generates a PIN for AT&T, but doesn't issue you a card themselves. If you later request a BOC card, they use the PIN that they previously generated for AT&T. So, it doesn't seem like you have control over PIN sharing. Possibly the exception is when you request from AT&T a card that's not related to your phone number. Stupid Customer (Dis)Service Quote of the Month: When I couldn't think of a good PIN for my one-number card, the U S West rep suggested that I use the same PIN as my unrestricted card, so it would be easier to remember!
johnk@opel.uu.net (John Kennedy) (02/06/90)
My belief in calling card algorithms is gone, now that I've specified the same 4-digit PIN for three different phone lines. (AT&T) John Kennedy johnk@opel.uu.uunet Second Source, Inc. Annapolis, MD