Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!netsys!vector!nobody From: comdesign!ivucsb!steve@apple.com (Stevie Lemke) Newsgroups: comp.dcom.telecom Subject: Re: PINs and Calling Cards as credit cards Message-ID: Date: 28 Jan 89 21:02:53 GMT Sender: chip@vector.UUCP Lines: 26 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@bu-cs.bu.edu X-Administrivia-To: telecom-request@vector.uucp X-TELECOM-Digest: volume 9, issue 36, message 2 Sorry if this has already been discussed (don't know how I could've missed it, but anyway...): Is the four digit PIN on a calling card computed from some sort of algorithm or is it randomly assigned for each phone number? It just seems strange that just about any phone anywhere can instantly tell if you dialed the correct PIN that corresponds to your calling card number. I realize computers are really fast these days and all, but I just thought it might be some sort of algorithm or something. However, that brings up the issue of what happens when someone discovers your number and you have to request a new one, so they can invalidate the old one. I've never had this happen, so I'm not sure what the procedure is. The only thing that got me thinking about this was this: I have a calling card from GTE for my home phone. I recently called AT&T to ask them for one of the magnetic (plastic) cards since my paper one doesn't work in the neat AT&T phones with card readers. I gave the AT&T employee my phone number, but not my LD PIN. She said the card that would be sent to me would have the same PIN as my GTE card. I was wondering if this was some sort of "PIN-sharing" they have worked out, or if they use this "algorithm". I guess it must be a database, but does anyone have any more positive info. on this? ----- Steve Lemke ------------------- "MS-DOS (OS/2, etc.) - just say no!" ----- Internet: steve@ivucsb.UUCP AppleLink: Lemke ----- uucp: apple!comdesign!ivucsb!steve CompuServe: 73627,570 ----- Quote: "What'd I go to college for?" "You had fun, didn't you?"