CDR: Re: Anonymous Remailers cpunk

[Steve Furlong]

<<Proposal to limit spam sent through anon remailers by requiring that
the traffic be encrypted>>

Jim Choate wrote:
> 
>> <<Jim wrote that there was no good way to tell if the message was encrypted>>
>>
> On Tue, 3 Oct 2000, Steve Furlong wrote:
> 
> > Why not just read the first 20 bytes of the body? If 90% or more aren't
> > printable ASCII assume the message is encrypted.
> 
> So, how come all of a sudden we're injecting algorithms that the users
> must know to even access the network? What sort of regulatory mechanism is
> required to mediate changes to the process?

Perhaps we're talking at cross purposes. This subthread came along
because some people have noticed that anonymous remailers are used for
an awful lot of spam. Peter Trei proposed that remailers could pass
along only encrypted mail. My understanding was that Alice, the
message's author, would encrypt the message with Bob's public key; Bob
is the end recipient: a person or a mailing list or whatever. Alice
would send the message through Ramona, the anonymous remailer. Ramona is
requiring that messages be encrypted as a means of filtering out spam.
Ramona does not need to know Bob's public or private keys; Ramona cares
only that the message is encrypted.

I'm assuming there's a way to tell with minimal difficulty if a message
is encrypted, without relying on an easily-spoofed X header line.
Perhaps someone who knows more about all of the many message protocols
can weigh in here.


> So, we can't send uuencoded text to guard against ASCII-pure (i.e. 7-bit)
> machines? Why not? I actualy prefer that sort of stuff because as a last
> resort I can check it visualy for errors.

You could uuencode your original message before encrypting it. You're
right, there could be a problem if one of the boxes in the chain handled
only 7 bits. Is that a realistic problem anymore? (That was a serious
question, not a dig.)


> A remailer should do NO content checking, ever. It's ONLY job is to route
> and destroy traffic analysis.

This would be an additional service for the recipients, filtering out
probable spam. It might be a minor inconvenience for Alice. On a
message-by-message basis it could be a minor inconvenience for Bob, but
if Bob had been receiving a lot of spam through the remailer it'd be a
neg gain. It'd be a huge inconvenience for Sue, the spammer, as
intended.

-- 
Steve Furlong, Computer Condottiere     Have GNU, will travel
   518-374-4720     sfurlong at acmenet.net