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Cyphernomicon 2.9

MFAQ--Most Frequently Asked Questions:
Remailers and Anonymity

    2.9.1. "What are remailers?"
    2.9.2. "How do remailers work?" (a vast number of postings have
            dealt with this)
           - The best way to understand them is to "just do it," that
              is, send a few remailed message to yourself, to see how the
              syntax works. Instructions are widely available--some are
              cited here, and up to date instructions will appear in the
              usual Usenet groups.
           - The simple view: Text messages are placed in envelopes and
              sent to a site that has agreed to remail them based on the
              instructions it finds. Encryption is not necessary--though
              it is of course recommended. These "messages in bottles"
              are passed from site to site and ultimately to the intended
              final recipient.
           - The message is pure text, with instructions contained _in
              the text_ itself (this was a fortuitous choice of standard
              by Eric Hughes, in 1992, as it allowed chaining,
              independence from particular mail systems, etc.).
           - A message will be something like this:
              Request-Remailing-To: remailer@bar.baz
              Body of text, etc., etc. (Which could be more remailing
              instructions, digital postage, etc.)
           - These nested messages make no assumptions about the type of
              mailer being used, so long as it can handle straight ASCII
              text, which all mailers can of course. Each mail message
              then acts as a kind of "agent," carrying instructions on
              where it should be mailed next, and perhaps other things
              (like delays, padding, postage, etc.)
           - It's very important to note that any given remailer cannot
              see the contents of the envelopes he is remailing, provided
              encryption is used. (The orginal sender picks a desired
              trajectory through the labyrinth of remailers, encrypts in
              the appropriate sequence (last is innermost, then next to
              last, etc.), and then the remailers sequentially decrypt
              the outer envelopes as they get them.  Envelopes within
    2.9.3. "Can't remailers be used to harass people?"
           - Sure, so can free speech, anonymous physical mail ("poison
              pen letters"), etc.
           - With e-mail, people can screen their mail, use filters,
              ignore words they don't like, etc. Lots of options. "Sticks
              and stones" and all that stuff we learned in Kindergarten
              (well, I'm never sure what the the Gen Xers learned....).
           - Extortion is made somewhat easier by anonymous mailers, but
              extortion threats can be made in other ways, such as via
              physical mail, or from payphones, etc.
           - Physical actions, threats, etc. are another matter. Not the
              domain of crypto, per se.

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