Article View: sci.crypt
Article #2234PGP server offers full two way encription
From: Dave Bunte
Date: Tue, 22 Dec 1992 20:22
Date: Tue, 22 Dec 1992 20:22
337 lines
14961 bytes
14961 bytes
[ Article crossposted from alt.drugs ] [ Author was ] [ Posted on Sat, 19 Dec 1992 23:42:22 GMT ] | PAX - Public Access Unix (Adelaide,South Australia) - Anonymous Posting Host | ============================================================================ | |Last modified: Fri Nov 20 18:55:52 CST 1992 | | Information about Anonymous & Privacy-Enhanced Posting. | ======================================================= | |PAX is conducting research into the viability of anonymous privacy- |enhanced mail as a means of providing practical, secure and confidential |electronic mail and news. An experimental server has been setup and |you are encouraged to use it. | |There are many anonymous posting services in existence which provide |anonymous electronic mail and posting to specific newsgroups where |posting is sometimes harmful to one's health or reputation ! Such |services allow you to: | | - post anonymously to those news groups | | - reply anonymously to posts by email | | - converse anonymously with another anonymous user, neither of | you knowing your real identities | |Privacy-enhanced electronic mail refers to the concept of encrypting |one's mail prior to sending it off into the ether, presumably to |someone at the other end capable of decrypting it. If one uses a |so-called "public key" method of encryption, then one can make one's |"public" key widely known so that anyone can encrypt mail to you, but only |you can decrypt it using your "secret" key. There is much development |going on in this area, but one quite popular public-domain implementation |is Philip Zimmermann's "Pretty Good Privacy 2.0" which makes use of a |number of cryptographic methods including the RSA algorithm in places |(See Legal Issues later on). PGP allows you to: | | - exchange public keys with another individual | | - encode messages to them that only they can read | | - receive messages from them that only you can read | |These tools are all very well for the specific purposes for which they |were designed, but unfortunately your anonymous message or post is not |actually anonymous until it gets to the machine that host's the service. |Anyone in between, including your own administrators, can in theory |read your post, even though they won't know to whom it is directed. What |is more they can also read replies addressed back to you. This can be |highly embarrassing at best, and result in dismissal or disconnection |at worst if your thoughts, beliefs or activities are disapproved of by |the powers that be, even if they are perfectly legal. | |PAX's privacy-enhanced anonymous services were conceived in the belief |that free speech and privacy are fundamental rights and that it is |high time the networks to which we are connected provided such services |on a routine basis. Seeing as they don't we have to make a start somewhere. | |This service provides: | | - conventional anonymous mailing and posting services via a "normal" | alias assigned in the usual fashion | | - the ability to post to ANY newsgroup that is carried out of PAX | (which includes most non-regional groups) | | - PGP 2.0 based privacy-enhanced mail & posting, including: | | - ability to register your "public" key with PAX, so that PAX | can send encrypted messages to you | | - local generation of a unique public key which is sent to you, | so that you can send encrypted messages to PAX | | - any encoded messages from you mailed to a user or newsgroup are | decrypted at PAX before being passed on in anonymous form | | - any anonymous replies to your "pgp" alias are encrypted before | being mailed to you | |For example, once you have obtained your PGP 2.0 software (as described |later) and got it going, and once you have generated and registered |your public key and received PAX's key in response, you will be able |to post to any newsgroup without anyone beyond your machine having |access to the plaintext of your post. | |Furthermore, if another user has registered in the same manner, and |you know their anonymous alias or are responding to one of their |anonymous posts, even though you don't know who they are and haven't |exchanged keys to communicate directly, the PAX service will automatically |decrypt any encrypted messages from you and re-encrypt them before |passing them on to the other person ! | | How to use it. | ============== | |All transactions are handled by email, and commands are selected by |the name of the alias to which you mail, not by the subject or body |of the message (which are ignored unless sending or posting a message). |The separator between the "anon" and the command is a dot (period,'.') |and nothing else will work ! Not '-', not '_', not ":", only a dot. | |The site to address mail is "pax.tpa.com.au". If this fails for some |reason, you may need to address it to the specific host (at present) |ie. "flash.pax.tpa.com.au". | |"Normal" (unencrypted) commands: | | - To get information (this message): | | mail anon.info@pax.tpa.com.au | | - To see what your "normal" alias is, or get one: | | mail anon.ping@pax.tpa.com.au | | - To send a reply to another anonymous user: | | mail anon.###@pax.tpa.com.au | | NB: | - eg. mail anon.36@pax.tpa.com.au | | - don't be creative ... anon.036 won't work | | - an attempt is made to strip off signature lines by discarding | everything after a line starting with "--" or "__" | | - To send a post to a newsgroup: | | mail anon.post.groupname@pax.tpa.com.au | | NB: | - eg. "mail anon.post.talk.abortion" will send a | post to "talk.abortion" | | - only the Subject field from your post is used, the rest of | the header is discarded | | - the newsgroup is selected by the alias; Newsgroup header | fields are discarded; hence cross-posting isn't feasible | | - signatures are stripped as above | |"PGP" (encryption) commands: | | - To register your public key with PAX: (ABSOLUTELY NECESSARY) | | mail anon.key@pax.tpa.com.au | | NB: | - first you have to make install pgp and make a key then send it | in a "anon.key" command | | - the body of the message MUST contain an ascii encoded public key | generated by PGP V2.0. You may use your regular public key that | you give to other people if you wish. The user ID name must be | unlikely to conflict with one PAX already has, so use your full | name, or include your email address or something. If you want | you can use a unique key just for PAX - it makes no difference. | If PAX already has a key of the same user-id it will reject yours. | Note that this means that you need different key user-id's on | different machines (or mail addresses anyway). | | # makes new keys & adds to your "keyring" | pgp -kg | Enter a user ID for your public key: First M. Last of somefirm | | # extract key in ascii form suitable for a message body | pgp -kxa "First M. Last of somefirm" savedfile pubring | | # send it to PAX | mail anon.key@pax.tpa.com.au <savedfile.asc | | - PAX will respond by sending you a new alias number and a | public key to add to your keyring to use to encrypt messages | to PAX. It will have a user ID name of "paxanon.publickey" | and you should add it to your public key ring by saving the | message in a file and presenting it as follows: | | pgp -ka savedfile | | Your life will be easier in future if you reply yes to the | certify question. | | - Note that now you may have two aliases, that sent in response to | the anon.key command and that sent in response to the anon.ping | command or previous unencrypted replies or posts. Any sunsequent | replies or posts that you encrypt before sending will be seen | to others as having come from the new alias, and replies will be | encrypted before being passed on to you. Any plaintext messages | you send will appear to have come from the original alias and | responses will also come back in plaintext. | | - Sending encrypted posts and replies. | | There are no other commands. If you encrypt a message and send it | using the "anon.reply" and "anon.post" groups, the software will | detect that they are encrypted, select the appropriate alias as | a return address, decrypt the message, and mail or post it. | | You should use PGP 2.0 to encrypt messages sent to PAX, using | the public key that PAX sent to you. DON'T FORGET TO SIGN your | message using the secret key corresponding to the public key | that you sent to PAX !!! Unsigned messages will be rejected | to ensure that the message is really from you and not someone | pretending to be you using your account or mailpath. | | Eg.: | | # sign and encrypt message for mailing to pax. | pgp -east message "paxanon.publickey" -u "First M. Last of somefirm" | mail -s "A test post" anon.post.alt.test <message.asc | | Note the -a (armor) and -t (text) options. Note also the subject | flag to mail - PAX will whinge if you post something without a | subject. | | Similarly, all messages to you will be signed using PAX's secret | key corresponding to the public key PAX sent to you, hence you | will know if the message really came from PAX and not someone | else using your public key. | | ***** NB. The ENTIRE encrypted segment will be passed on after | it has been decrypted. There is no processing of any contained | header (though it won't work as a header), nor any removal of | signature information within the encrypted text. Take great care | to ensure that there is no identifying information within the | encrypted text. ***** | | Any plain text accompanying the encrypted text will be discarded. | The Subject header field is still passed on during postings as | with "normal" unencrypted posts. | | More work may be done on these "features" if there is sufficient | demand for it :). | |Miscellaneous administrative commands: | | - To see the current status of the system (message of the day): | | mail anon.status@pax.tpa.com.au | | - To send mail to a human administrator: | | mail anon.admin@pax.tpa.com.au | | Mailing List | ============ | |To send mail to/join/unjoin a mailing list about this service, and |anonymous services in general: | | mail anon.list@pax.tpa.com.au | mail anon.subscribe@pax.tpa.com.au | mail anon.unsubscribe@pax.tpa.com.au | | | How secure is it ? | ================== | |Not bad. Clearly it depends on the security of the underlying PGP 2.0 |software which is discussed at length in its documentation. | |The keys are stored, and the messages encrypted and decrypted on |a server which also hosts a Public Access Unix system. These files |are protected by the usual Unix security mechanisms, but in the |event of a security breach could conceivably become visible. The |keys would hence be compromised and any messages passing through |could be decrypted. The PAX administration could theoretically |access the keys and files at will of course. | |It is hard to conceive of an alternative implementation which links |anonymity with privacy enhancement however. This is no substitute for |a direct person to person link with certified keys and this service |should not be used as a substitute for such if security is a primary |concern. | | Legal Issues. | ============= | |PGP 2.0's use of the RSA algorithm is a problem in the US where a patent |is now held on the algorithm, despite its widespread promulgation before |the patent was obtained. The PGP documentation discusses this issue at |length. | |Sufficeth to say, this service is provided by a site in Australia and |hence should not be subject to the constraints imposed by the US patent. |The service is offered to anyone who can reach this site by mail, in |addition to PAX's own users, and there is no intention of obtaining any |commercial gain by providing the privacy-enhanced anonymous service. | |Whether individuals in the US can legally use the PGP software to use the |service provided by PAX for their own personal use, without first obtaining |a license to use the RSA algorithm is an untested issue. Certainly the |software is widely available even though it is now maintained outside the |US. | |No such concerns should apply anywhere other than the US. | |This project is an experiment to see if the concept is feasible and if |there is any demand for it. The software is crude, but functional, |but it is quite possible that it will fail in unforeseen circumstances. |It is designed to loose or fail to pass on a message rather than post or |return plaintext (which would be very undesirable) but there can be no |guarantees. It is conceivable that plaintext might get sent where it |was not intended, and PAX assumes no responsibility for the consequences. |At least this would be no worse than the situation that prevails with |current anonymous services. | |THIS IS EXPERIMENTAL SOFTWARE IN A STATE OF FLUX - YOU HAVE BEEN WARNED. | |END OF FILE | |- -- |** Anonymity & Privacy by PAX - Public Access Unix (Adelaide,South Australia) ** |anon.admin@pax.tpa.com.au (a human) anon.info@pax.tpa.com.au (for help) |anon.ping@pax.tpa.com.au (get alias) anon.key@pax.tpa.com.au (register key) |anon.###@pax.tpa.com.au (reply) anon.post.g@pax.tpa.com.au (post to g) |anon.list@pax.tpa.com.au (to mailing list) |anon.subscribe@pax.tpa.com.au anon.unsubscribe@pax.tpa.com.au | |For dialup Unix access phone +61-8-235-9010 - online registration. ------------------------------------------------------------------------- To find out more about the anon service, send mail to help@anon.penet.fi. Due to the double-blind system, any replies to this message will be anonymized, and an anonymous id will be allocated automatically. You have been warned. -- The author makes no representations about the suitability of these opinions for any purpose. They are provided "as is" without express or implied warranty...
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arc1-ca.pugleaf.net!sparky!uunet!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!magnus.acs.ohio-state.edu!csn!neocad!bunteShow Full Headers
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Newsgroups: sci.crypt Path: arc1-ca.pugleaf.net!sparky!uunet!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!magnus.acs.ohio-state.edu!csn!neocad!bunte From: bunte@neocad.com (Dave Bunte) Subject: PGP server offers full two way encription Message-ID: <1992Dec22.202244.9159@neocad.com> Organization: NeoCAD, Inc. X-Newsreader: TIN [version 1.1 PL8] Date: Tue, 22 Dec 1992 20:22:44 GMT Lines: 338