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Howto use a Type I Anonymous Remailer (Cypherpunk)

Thu, 07/20/2006 - 5:45pm — dave

Sometimes you need to send a message anonymously but cannot install software on the machine you are using so a Type II or III Remailer will not work. If you have access to GnuPG or PGP and an email client then you can use a Cypherpunk remailer.

Note: For the following examples, we will use the Cthulu remailer at mixmaster@cthulu.joatcrafts.org and the Borked remailer at remailer@pseudo.borked.net which both provide Type I (Cypherpunk) and Type II (Mixmaster) services.  
Step 1: Retrieve the Remailers PGP / GnuPG Public Key and add to your key ring.

For most remailers, retrieving the key is as simple as sending an email with the subject: remailer key. Like so:

From: Dave
To: mixmaster@cthulu.joatcrafts.org
Subject: remailer-key

The remailer will then reply with a message like:

From mixmaster@cthulu.joatcrafts.org Fri Jul 21 14:25:31 2006
Date: Fri, 21 Jul 2006 13:22:14 -0700 (PDT)
From: Cthulu Anonymous Remailer <mixmaster@cthulu.joatcrafts.org>
To: dave
Subject: Remailer key for cthulu
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=iso-8859-1
Status: RO

$remailer{"cthulu"} = "<mixmaster@cthulu.joatcrafts.org> cpunk mix middle pgp pgponly remix latent hash cut test ek ekx esub inflt50 rhop20 reord klen300";

Here is the PGP key:

Type Bits/KeyID    Date       User ID
pub 1024R/B9DEF439 2001/12/17 Cthulu Anonymous Remailer <mixmaster@cthulu.joatcrafts.org>

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: N/A

mQCNAzwe0oAAAAEEAMG5BV0EJoZwiV2km3uL7PuKpZSC6JdvYY6c/gcQLYGnQQIH
frgKEG68hIOWbpmI0ZvsuxxQuHYOafsdcfmSRMpSOEtoQcYFEf+bWYnMXcdkE6x4
MvgrxsRvROn0ip7zKhnRDR9TB8tdUQyAmwJaPE44/6aNx3+iaTXlLR253vQ5AAID
tDtDdGh1bHUgQW5vbnltb3VzIFJlbWFpbGVyIDxtaXhtYXN0ZXJAY3RodWx1Lmpv
YXRjcmFmdHMub3JnPokAlQMFEDwe0oA15S0dud70OQEB4LMD/3lNaWoWTvaXHsTI
OF/PPf5yHtpoPvYOa5VVcjacHoRNe+ecJvr/fvOvHwS1xwG/yoI9yS9juASjjz3b
2cciaNLea/zYnEKEtZdTZHGuFlCDXySYnMXR0oucsfXjBs9B45IMtW7w06lB8EII
DhYF60hi65yRiwjOfs9uEGoT5etE
=Rq08
-----END PGP PUBLIC KEY BLOCK-----

Type Bits/KeyID    Date       User ID
pub 1024D/CD2E8215 2001/12/17 Cthulu Anonymous Remailer <mixmaster@cthulu.joatcrafts.org>
sub 1024g/243F8E2C 2001/12/17 

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: N/A
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=OAw3
-----END PGP PUBLIC KEY BLOCK-----


Here is the Mixmaster key:

=-=-=-=-=-=-=-=-=-=-=-=
cthulu mixmaster@cthulu.joatcrafts.org 03395f366dc6a70e673ac5d548ca8ec1 2.9beta32 MC

-----Begin Mix Key-----
03395f366dc6a70e673ac5d548ca8ec1
258
AAS2XJa9bQHEjEb6FfSOaPnfk95nxQEVeAF5gpGA
b8Y9vr8z5qaoNasBmNctbVxL0MN4VmVxtpFje1pl
eB7BV7O76rH2c1InKLT3brSYUNGLWmFTqbwC3CQl
GaqUmmfJTG2g4OC3LvA+CS+1h5w5Lz7zQEsP6h7C
CrBg6fpWBXmYLQAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAQAB
-----End Mix Key-----
Note: You can also generally retrieve remailer specific help information by sending a message with the subject "remailer-help".

Then we simply save the message to a file and add the key to our GPG keyring so we can use it. 

user@host:~ gpg --import keys.txt
gpg: key B9DEF439: "Cthulu Anonymous Remailer <mixmaster@cthulu.joatcrafts.org>" imported
gpg: key CD2E8215: public key "Cthulu Anonymous Remailer <mixmaster@cthulu.joatcrafts.org>" imported
gpg: Total number processed: 2
gpg:               imported: 2
gpg:              unchanged: 0
user@host:~
 
Step 2: Compose Message.

The first step is to write the message that you wish to send and save it as a text file.

Template:

::
Anon-To: <Recepient Email Address>
Latent-Time: <Time Delay>

##
Subject: <Subject>

<Message>

For this demonstration, we'll use the following message:

::
Anon-To: someone@feraga.com
Latent-Time:  +0:00

##
Subject: Cypherpunk Remailer Test.

This is a test of a Cypherpunk Remailer via Cthulu.
 
Step 3: Encrypt Message. Note: Some Cypherpunk remailers will accept nonencrypted messages but their number is dwindling with time.

user@host:~ cat test_cypherpunk | gpg -ea -r B9DEF439 > test_cypherpunk.encrypted
gpg: B9DEF439: There is no assurance this key belongs to the named user

pub  1024R/B9DEF439 2001-12-18 Cthulu Anonymous Remailer 
 Primary key fingerprint: C3 8A 93 7B 76 10 8C D3  C4 89 4B EF 30 5C C4 EF

It is NOT certain that the key belongs to the person named
in the user ID.  If you *really* know what you are doing,
you may answer the next question with yes.

Use this key anyway? (y/N) y
user@host:~
Note: You can stop the "Use this key anyway?" prompt by locally signing the key with gpg --lsign-key B9DEF439  
Step 4: Add a few layers to increase the security.

While the message is ready to send now, you generally want to bounce it through a few remailers to maximize the security. To do so take our current message and put it into a message for another remailer. You can repeat this step as many times as you like or skip it for messages for whom one hop is secure enough.

::
Anon-To: mixmaster@cthulu.joatcrafts.org

##
Subject: Anonymous Message

::
Encrypted: PGP

-----BEGIN PGP MESSAGE-----
Version: GnuPG v1.4.3 (GNU/Linux)

hIwDNeUtHbne9DkBA/9drtL/O0VOtn/dZzAw6HEdESj+sY/kwpm6941T3TzbZWKw
nJM8785ZEtXQ03qGEMx/J29MgGxFTgeQjOiKmosjJibTyboppu9Jd8dEmKAjwJVh
BCp5hdxXyqGl4k4VDpZJnNZM0OcMjg+8FyUhGhzqZ5vK8vLD8K6WucalYWl4tsl3
YICABlFCWxoaKenCODprZhazFvPUiR4FS8lrJwDEmgZ4d9epNyZvnkGJm8NIPJZv
zG0XGeM8ROXYMevETo6N03eD8eGKjcFe84Rw8KGU5tex/G7Uvl6q6YxYVN4y7qlD
WsuX2/AZS7hhxdSfo8TBDIwmLM29l0w=
=xS0h
-----END PGP MESSAGE-----

Now take that file and encrypt it with the next remailers public key.

user@host:~ cat test_cypherpunk.encrypted | gpg -ea -r 1151BB09 > test_cypherpunk.layer2
user@host:~
 
Step 5: Place Encrypted Message into an Email and send to the remailer.

Now open your favorite email client and build a message with the following template:

::
Encrypted: PGP

-----BEGIN PGP MESSAGE-----
<Insert encrypted message here>
-----END PGP MESSAGE-----

So our test message should look something like:

From: Dave
To: remailer@pseudo.borked.net
Cc: 
Bcc: 
Subject: Anonymous Message.

::
Encrypted: PGP

-----BEGIN PGP MESSAGE-----
Version: GnuPG v1.4.3 (GNU/Linux)
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=ohYQ
-----END PGP MESSAGE-----

When its ready, send it.

Comments

Tue, 01/15/2008 - 7:21pm — Anonymous Email (not verified)

Thanks for this easy to

Thanks for this easy to read tutorial. What is the difference between MixMaster and CyperPunk from the perspective of a user?