On Sun, Aug 03, 2003 at 01:45:54AM -0500, Michael D. Schleif wrote: > Also sprach David Fokkema (Sun 03 Aug 02003 at 08:26:11AM +0200): > > A receives challenge from B's C-R system which originates (of course) > > from B's e-mail address. > > Isn't that a shaky assumption? I use eight (8) different email > addresses; but, *all* incoming email is grabbed by one (1) fetchmail, > processed by one (1) procmail, and inserted into one (1) maildir > hierarchy. Yes, I use mutt to automate that email address used, > depending on recipient; but, how do you -- or, more properly, your c-r > system -- know which email address that I will use for my own c-r > challenge?
Even if you have one fetchmail running six mail addresses, there's still the To: header... So, A sends B1 a mail, B1 is auto-whitelisted, B{1,2,3,4,5,6} is gotten by B's fetchmail and B's C-R sends a challenge according to the To: header. In this case, the challenge comes from B1. > > A's C-R system recognizes B (and thus B's C-R) and dumps the challenge > > in A's mailbox. > > What am I missing? I thought that the *ONLY* way for A to receive email > from B is for B to respond to A's challenge with the proper password > !?!? No. Either B has to respond to a challenge (password or alike) or B has to be whitelisted. If B is whitelisted, he will not get a challenge. Never. Since A sends B1 a mail, B1 is whitelisted. Indeed, B2 is not, and would receive a challenge. > Perhaps, c-r is akin to ai, and B's challenge auto-magically includes A's > proper password in B's initial challenge? How convenient . . . If we had AI that good, they would probably read through our mails and perform the function of a filter just as good (or better) as we would've done it. C-R is only functional as long as filters aren't perfect, IMHO. > > A responds to the challenge and the link is set up. > > As I understand this, A will never see B's challenge -- lacking, > obviously, that proper password -- even if B's challenge originates with > that initial email address. In my case, there is a 12.5% chance that > B's challenge will be from that initial email address ;< > > Furthermore, if you are right, and the link is setup at this point, then > clearly, the password is ubiquitous, and any spammer need only respond > by whatever means, and you've delayed receiving your plate of spam, but > eat it you must. The password is supplied only once. B is whitelisted, so will never get a challenge again. Any spammer who uses B as its From: address, will walk right through your door, I guess... However, I have _never_ gotten any spam from a person I knew. But, of course, I only get a few spam a day, not tens or more. > Frankly, I am not interested in telling spammers that my email address > is legitimate. In fact, I much prefer forwarding spam to proper > authorities, and ignoring the spammer directly. Do you think that > spammers want to know email addresses that will respond to them? I think they do. There is a lot of HTML spam floating around which contain links to pictures in the form href server/3030404ajsj4jsa09303-4j3l3022asjs342j3.gif. The usefulness and meaning of this particular number is left as an exercise to the reader, ;-) > What else do you think? I think that C-R systems really work, except for the irritation and agitation it can cause. C-R systems are designed to work in both an internet with almost no C-R systems and an internet with almost every one using C-R. Links can be set up between C-R systems. However, if a spammer uses an address that you have whitelisted it won't work. It might be possible that this is more rare than SA getting a false negative. The only disadvantage I see of C-R, is that some people refuse to reply to a challenge. David -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]