When the network that is now the Internet was first designed, it was assumed that all users wanted
to be found. No one had reason to hide, and it seemed sensible that researchers should be able to
locate each other. Utilities were therefore created to facilitate such finding.

Since those early days, the rise of multiple protocols has made finding people even more convenient.
As you will see later in this chapter, the old days demanded a high level of networking knowledge
from the user. Today, finding or identifying most individuals is trivial. Throughout this chapter, I
examine those techniques, as well as some concepts about wholesale tracing (tracing many
individuals at one time).

You may wonder why this is deemed a security issue. In truth, it really isn't--not yet. As you read
this chapter, however, you will learn that the Internet is a powerful tool for domestic spying.
Law-enforcement and intelligence agencies already conduct such practices on the Internet, and for
them, the Network is a bonanza. No search warrant is needed to "study" the activity of someone on
the Internet. Likewise, no warrant is needed to compile lists of individuals who law enforcement
perceive to be involved in illegal (or even seditious) activity. This is not a joke. If you harbor radical
political views, by the end of this chapter, you may elect to forever keep those views to yourself (or
gain a decent education in cryptography).

Before I begin, I need to make one statement regarding screenshots and diagnostic network
information contained within this chapter. Certain methods of finding individuals demand the use of
search engines. Unfortunately, to my knowledge, the law has not been adequately settled regarding
the reprinting of an individual's e-mail address without his consent. Because of this, I cannot provide
screenshots of searches because they necessarily contain the e-mail addresses of users unknown.

Therefore, the searches have to be described rather than illustrated. I do apologize for this.
However, upon reflection, I would not want my e-mail address published, and I see no reason why
anyone else would, either. The argument is often made that anyone who posts to a Usenet
newsgroups has at least given an implied form of consent. I do not support that view. So, I am afraid
that we shall have to get along as best we can by description as opposed to screenshot. I have taken
pains to explain each step carefully to provide the utmost clarity. I hope that will suffice.

So, let us begin at the beginning, at the heart of your server. We will start at home base and work
our way outward.

What's in a Name?

There are two forms of user identification that apply to all platforms: your e-mail address and your IP
address. It is often theorized that if one is obscured, the other can never be found. That is untrue.
Without chaining messages through a series of trusted anonymous remailers (remailers that are
purportedly secure), anonymity on the Internet is virtually impossible. Anonymous remailers are
discussed in Chapter 7, "Birth of a Network: The Internet."

It is possible, however, to make yourself relatively invisible, and that is probably what most
individuals would like to do. Before I get more specific, however, there are some utilities you need to
know about, as well as methods of tracing individuals. I'll start with finger.

finger

The finger service is a utility common to the UNIX platform. Its purpose is to provide information
about users on a given system. In practical operation, finger works like most other services available
in UNIX. Figure 13.1 demonstrates the use of Finger32, a popular finger client for the Microsoft
Windows platform.

Figure 13.1.
The finger query process.
 

     Cross Reference: Finger32 is a small application port of the UNIX utility finger. It is
     available here:
     ftp://hyper.net.au/Win95nt-apps/Finger/Wsfinger/Wsfngr32.zip
 

The finger service relies on the client/server model, which is a recurring theme in Internet
applications. This model works as follows: machines running server applications distribute
information to clients. Clients are programs designed to accept and interpret information from server
applications. For example, you use a Web browser (or client) to read information forwarded by a
Web server (the HTTP server).

In any event, the finger client-server relationship works as follows: On the targeted machine (almost
always a UNIX system), there is a server running called fingerd. This is more commonly referred
to as the finger daemon. Its purpose is to answer requests from finger clients from the void.

The finger daemon can return different information, depending largely on the configuration of the
server and the user's personalized settings. For example, sometimes an "open" UNIX server (that is,
one not running a firewall) will disallow finger access. This is done by disabling the finger daemon,
removing it from the file /etc/inetd.conf. In this case, the finger service is never started. Any
client-issued finger request forwarded to such a machine will meet with a blank response (or
perhaps, Connection Refused.).

Many organizations, particularly ISPs, government sites, and private corporations, disable finger
services. Each has an interest in preserving the privacy of its users, and that is usually the reason
given for disabling the service. As you will learn later, however, their motivation may also be system
security.
 

     TIP: Certain vital information about the system can be culled by fingering system IDs
     such as root, bin, FTP, and so on. On that account, some sites will disable finger
     services altogether. It is thought that by killing the finger and RPC services, one can
     restrict the amount of revealing information available to crackers in the void. To some
     extent, this is true.
 
 

     Cross Reference: An excellent paper written by Dan Farmer and Wietse Venema
     addresses this issue: "Improving the Security of Your Site by Breaking Into It." The
     paper is so widely distributed on the Internet. Here is a very reliable source:
     http://www.alw.nih.gov/Security/Docs/admin-guide-to-cracking.101.html.
     (This is a government site, so with all probability, this link will be good for many years
     to come.)
 

Some sites do not disable finger services altogether, but instead put restrictions on what type of
information can be accessed. For example, by default, the finger daemon allows a systemwide finger.
Anyone can be fingered, including special or privileged accounts. When systemwide fingering is
allowed, one can gather information on all users currently logged to the machine. This is done by
issuing the following command at a UNIX command prompt:

finger @my_target_host.com

The @ symbol has essentially the same effect as the asterisk does in regular expression searches.
When it is used, the user is fingering all users currently logged to the target machine. This is most
useful when targeting small providers that have few customers, or when conducting such a finger
query late at night. Certainly, fingering a company as large as Netcom in this manner would be
foolish. (The response forwarded by the server would likely be many pages in length. The only valid
reason for doing this would be to generate a database of Netcom users.) At any rate, some
organizations will disallow such a request, instead forcing the requesting party to specify a particular
user.

Other sites make use of hacked finger daemons, either created in-house or available as distributions
from other sites across the Internet. These are finger daemons that have enhanced features, including
advanced configuration options.
 

     Cross Reference: One such hacked finger daemon is the Configurable Finger
     Daemon, or cfingerd. Written by Ken Hollis, cfingerd provides security functions
     not available in garden-variety finger servers. It is considered to be an excellent
     replacement to the standard distribution of finger. It is available free of charge at
     ftp://ftp.bitgate.com/pub/cfingerd/.
 
 

     Cross Reference: For more generalized understanding of the finger daemon process,
     I suggest viewing the source for any public-domain finger client. There is a nice online
     resource for this at http://araneus.york.ac.uk/owtwaww/finger.htm.
 

At any rate, taking you through the process of a finger inquiry will take just a few moments, but in
order for you to exploit the example, you need a finger client. UNIX users, however, have no need
for a finger client, because this is included in the basic distribution. The same is true of Windows NT.
So this little section is primarily for Windows, Mac, and OS/2 users. The finger clients are listed in
Table 13.1.

Table 13.1. Finger clients for non-UNIX, non-NT users.

 Platform
             Client
                     Location
 Windows
 (All)
             WSFinger
                     ftp://papa.indstate.edu/winsock-l/finger/wsfngr14.zip
 Macintosh
             Macfinger
                     ftp://ftp.global.net.id/pub/mac/internet/finger-15.hqx
 OS/2
             FFEU
                     http://www.musthave.com/OS2/ftp/ffeu101.zip
 

For demonstration purposes, I will use Finger32, a popular finger application for Windows 95. The
application is simple to use; it presents the user with a self-explanatory screen from which you
choose your host. (See Figure 13.2.)

Figure 13.2.
The Finger32 opening screen--choosing a host.

When you choose this option, a dialog box appears, requesting a host and username. (See Figure
13.3.)

Figure 13.3.
Specifying your target.

Providing the target is running a finger server, the return output should read something like this:

Login name: root                        In real life: 0000-Admin(0000)
Directory: /                            Shell: /sbin/sh
Last login Tue Feb 18 19:53 on pts/22
New mail received Wed Feb 19 04:05:58 1997;
  unread since Wed Feb 19 03:20:43 1997
No Plan.

This tells you several things, including the directory where root@samshack resides (/), the shell he
or she is using (/sbin/sh), and some details on last login and mail. (Hard-core hackers will know
that it also tells you that root@samshack.com is using Solaris as an operating system. Note the
0000-Admin[0000] string.)

This information does not appear to be particularly revealing; however, in 70% of all cases, the field
In real life is filled with a name. Worse still, at some universities, you can get the name,
telephone number, dorm room number, and major of students enrolled there (not that the major
matters particularly, but it provides some interesting background).

The information available on a finger query is controlled primarily by the system administrator of a
given site, as well as what information you provide on your initial signup. Most new users are not
aware of this and provide all the information they can. Most people have no reason to hide, and
many provide their office telephone number or even their home address. It is human nature to be
mostly honest, especially when the entity they are providing information to seems benign.

So the process of identification usually either starts or ends with a finger query. As noted previously,
the finger query uses your e-mail address as an index. This leads us immediately into an area of some
controversy. Some individuals believe that by changing their e-mail address in the Netscape
Navigator or Microsoft Internet Explorer Options panels, they obscure their identity. This is not true.
It simply makes your e-mail address more difficult to obtain. I will get to this subject momentarily.
For now, I want to continue with finger, offering a little folklore. The following is a classic Internet
story. (If you've ever fingered coke@cs.cmu.edu, skip these next few paragraphs.)

Years ago, the computer science department staff at Carnegie-Mellon University had a gripe about
their Coke machine. Often, staffers would venture down to the basement, only to find an empty
machine. To remedy this problem, they rigged the machine, connecting it to the Internet (apparently,
they did this by wiring the machine to a DEC 3100). They could then issue a finger request and
determine the following things:

     How many sodas were in each slot

     What those sodas were--Coke, Diet Coke, Sprite, and so on

     Whether the available sodas were cold

Today, you can still issue a finger request to the Coke machine at CMU. If you were to do so, you
would receive output very similar to the following:

[ Forwarding coke as "coke@l.gp.cs.cmu.edu" ]
[L.GP.CS.CMU.EDU]
Login: coke                             Name: Drink Coke
Directory: /usr/coke                    Shell: /usr/local/bin/tcsh
Last login Sun Feb 16 18:17 (EST) on ttyp1 from GS84.SP.CS.CMU.EDU
Mail came on Tue Feb 18 14:25, last read on Tue Feb 18 14:25
Plan:
    M & M                   Coke Buttons
   /----\           C: CCCCCCCCCCC.............
   |?????|       C: CCCCCCCC....   D: CCCCCCCCCC..
   |?????|       C: CCCCCCCCCCCC   D: CCCCCCCC....
   |?????|       C: CCCCCCCC....   D: CCCCCCCCC...
   |?????|                         C: C...........
   \----/                          S: C...........
      |        Key:
      |          0 = warm;  9 = 90% cold;  C = cold;  . = empty
      |          Beverages: C = Coke, D = Diet Coke, S = Sprite
      |          Leftmost soda/pop will be dispensed next
    --^--        M&M status guessed.
                 Coke status heuristics fit data.
Status last updated Wed Feb 19 00:20:17 1997

As you can see, there is no end to the information available with a finger query. The story of this
Coke machine was told by Terence Parr, President and Lead Mage of MageLang Institute
(http://www.magelang.com/), at the 1996 Netscape Developer's Conference at Moscone
Center in San Francisco. Reportedly, Parr was demonstrating a Java application that could emulate
this Coke machine hack when suddenly, a former CMU student, Michael Adler, rose to the
occasion. Adler explained the hack in detail, having firsthand knowledge of the Coke machine in
question. In fact, Adler was largely responsible for adding the temperature index function.

At any rate, many administrators insist on supporting finger, and some have legitimate reasons. For
example, a finger server allows easy distribution of information. In order for the finger server to
support this functionality, the targeted user (or alias) must have a plan file. (The Coke machine at
CMU certainly does!) This file is discussed in the next section.

The Plan File (.plan)

On most UNIX servers, user directories are kept beneath the /home/ or /usr directory
hierarchies. For example, a user with a username of cracker will have his home directory in
/home/cracker. (This is not set in stone. System administrators are responsible for where such
directories are kept. They could specify this location as anywhere on the drive, but the typical
placement is /usr or /home.)

Typically, in that home directory are a series of special files that are created when the user accesses
his account for the first time. For example, the first time he utilizes the mail program Pine, a series of
files are established, including .pinerc, which is the configuration file for this mail client.

These files are referred to as dot files, because they are preceded by a period. Most dot files are
created automatically. The .plan file, however, is not. The user must create this file himself, using
any text editor (for example, vi or pico). This file can be closely correlated with the plan.txt file on
a VAX system. Its purpose is to print user-specified information whenever that user becomes the
target of a finger query. So, if the user saves into the .plan file a text recounting his life history, that
text will be printed to the STDOUT of the party requesting finger information. The .plan file is one
way that information can be distributed via the finger server. (Note that you, the user, must create
that .plan file. This is not automatically generated by anyone else.) If you examine Figure 13.1
again, this will seem a bit clearer.
 

     TIP: You may have encountered servers or users that suggest that you Finger for
     more info. Usually, this entails issuing a finger request to an address like
     info@targethost.com. Most often, the information you receive (which could be
     pages of plain text) comes from the .plan file.
 

There are other reasons that some administrators keep the finger service operational. Entire
programs can be launched by specifying a particular address to be fingered. In other words, one
could (although it is not recommended) distribute text files this way. For example, you could write an
event handler to trap finger queries aimed at a particular user; if user A were fingered, the server
would send a specified text file to the requesting party. I have seen more than one server configured
this way, although it is more common to see mail lists designed in this manner.

For whatever reason, then, finger services may be running on the server at which you have an
account. If you have never bothered to check what information is available there, you can check
now by issuing a finger request to your own account. You can also examine this information (the
majority of it, anyway) by issuing the following command at a shell prompt:

grep your_username /etc/passwd
 

     TIP: This technique will only work on servers that use non-shadowed password files,
     or those that are not employing NIS. In those instances, you may have to issue a
     command more like this:

     ypcat passwd || cat /etc/passwd | grep user_name
 

This command will print the information the server holds on you in the /etc/passwd file. Note that
this information will be visible even if the server makes use of shadowed password entries.

So now you know: The names of the majority of Net citizens are there for the taking. If your system
administrator insists on using finger, there are several things you can do to minimize your exposure:

     Use the popular utility chfn to alter the finger information available to outsiders

     If chfn is not available, request that the sysad change your information

     Cancel your current account and start a new one
 

     NOTE: If you believe in harsh solutions and you want to discourage people from
     repeatedly fingering your account, write a .plan file that forwards a few megabytes of
     garbage. This is most useful if your sysad refuses to assist, chfn is unavailable, and
     some joker is trying to clock your movements using finger.
 

Of course, perhaps you are not concerned with being fingered as much as you are concerned with
who is doing the fingering. If so, you need MasterPlan.

MasterPlan

MasterPlan is an excellent utility. Written by Laurion Burchall and released in August 1994, this
product takes an aggressive approach to protecting your privacy. First and foremost, MasterPlan
identifies who is trying to finger you. Each time a finger query is detected, MasterPlan attempts to get
the hostname and user ID of the fingering party. These variables are piped to an outfile called
finger_log. MasterPlan will also determine how often you are fingered, so you can easily detect if
someone is trying to clock you. (Clocking refers to the practice where user A attempts to discern
the habits of user B using various network utilities, including finger and the r commands.)
 

     TIP: The r commands consist of a suite of network utilities that can glean information
     about users on remote hosts. I will discuss one of these, a utility called rusers, in a
     moment.
 

Typically, a cracker writes a shell or Perl script to finger (or otherwise query) the target every
specified number of minutes or hours. Reasons for such probing can be diverse. One is to build a
profile of the target; for example, when does the user log in? How often does the user check mail?
From where does the user usually log in? From these queries, a cracker (or other nosy party) can
determine other possible points on the network where the user can be found.

Consider this example: A cracker I know was attempting to intercept e-mail trafficked by a
nationally renowned female journalist who covers hacking stories. This journalist had more than one
account and frequently logged into one from another. (In other words, rather than directly logging in,
she would chain her connections.) This is a common practice by individuals in the public eye. They
may want to hide from overly enthusiastic fans (or perhaps even legitimate foes). Thus, they preserve
at least one account to receive public mail and another to receive private mail.

By running a probing script on the journalist, the cracker was able to identify her private e-mail
address. He was also able to compromise that network and ultimately capture all the journalist's
mail. The mail was primarily discussions between the journalist and a software engineer in England.
The subject matter concerned a high-profile cracking case in the news. (That mail was later
distributed to crackers' groups across the Internet.)

In any event, MasterPlan can help to identify these patterns, at least with respect to finger queries.
The utility is small, and easily unpacked and configured. The C source is included, and the
distribution is known to compile cleanly on most UNIX systems. (The exceptions are reportedly
Ultrix and the NeXT platform.) One nice amenity for Linux users is that a pre-compiled binary
comes with the distribution. The standard distribution of MasterPlan is available at

     ftp://ftp.netspace.org/pub/Software/Unix/masterplan.tar.Z

The Linux compiled version is available at

     ftp://ftp.netspace.org/pub/Software/Unix/masterplan-linux.tar.Z

As you've now seen, the finger utility is dangerous and revealing. More and more sites are now
disabling finger services, at least with respect to external queries. For various reasons, however,
many providers simply do not bother to shut it down.
 

     TIP: If you want to see an example of mapping an IP address to a username
     dynamically, trying fingering ppp@wizard.com. This host has apparently aliased out the
     PPP connections so that the entire list of users connected via PPP can be examined
     using the finger command. Thus, if you receive a message from a user in that domain,
     but the user obscured his e-mail address, it could still be culled using the finger
     command. By fingering the entire block of current PPP addresses, you can map the IP
     to a username and from there, finger the username. By going through this process, you
     can easily obtain the e-mail address of a user in that domain, even if he is trying to hide.
 

Note that MasterPlan will not prevent someone from fingering you; it will simply identify that party
and how many times the finger request has been issued.

But all this assumes that your provider allows finger requests from the void. Suppose for a moment
that it doesn't. Does this mean that you are safe and that you shouldn't worry about your name being
revealed? Hardly. It simply means that a standard finger query will fail to render any information
about you.

Suppose that someone is attempting to finger you and discovers that finger requests from the void
are prohibited. Suppose further that this person is determined to find your real name and is willing to
risk an angry message from your provider to his own. In such a case, the nosy party will initiate a
Telnet session to your provider's mail server. (This is done by initiating a Telnet request to port 25.)

In most cases (except those where the provider is paranoid or running a firewall), a server will
accept a Telnet connection to port 25 (the port that sendmail runs on). Such a connection looks like
this:

220 shell. Sendmail SMI-8.6/SMI-SVR4 ready at Wed, 19 Feb 1997 07:17:18 -0800
 

     TIP: The preceding piece of a started Telnet session was initiated on a Solaris 2.5
     SPARC station 20. Different flavors of UNIX will provide different strings at the
     beginning of the session. However, almost all reveal the operating system and version
     number.
 

If the nosy party can get to such a prompt, there is better than an 80 percent chance that he will have
your name momentarily. The information is collected by issuing the following command:

expn username

This command requests that the mail package expand a username into an e-mail address and real
name. This is a feature (not a bug) of the sendmail package. The response will typically expand into
something similar to

username <username@target_of_probe.com> Real Name

The first field will report back the username or user ID that you request to be expanded. This will be
followed by the person's e-mail address and finally, his "real" name.

Note that the expn function can be disabled by the system administrator, although few actually do it.
There are reasons for this, and the most probable is that administrators simply fear fiddling with the
sendmail configuration. Sendmail is a notoriously complex and powerful program that has evolved
into a huge package. There are so many options for it that an entire book could be written just on its
configuration. It is for this reason, no doubt, that sendmail has consistently been the source of holes
in Internet security. So you might wonder why the program is even used at all. That is easy to
explain. Sendmail is the most successful program for transport of electronic mail ever created.
Millions of users all over the world send mail each day using this program.

In any event, if the expn function is operable, the nosy individual will still get your real name, if it is
available. Unfortunately, even if the expn function has been disabled, the snooping party can still
verify the existence of your account using the vrfy function. This is academic, however; if your
provider's sendmail system honors Telnet sessions, there is a greater than 70 percent chance that one
or both of these functions is available.
 

     TIP: You will find that many other versions of sendmail-- which has now been ported
     to almost every platform-- will also render this information.
 

Currently, other than rewriting your account so that your real name does not appear in the
/etc/passwd database, there is no way for you to exercise control over these remote functions.
sendmail issues must be resolved by root. Moreover, it is highly unlikely that a system administrator
will fiddle with his or her sendmail configuration just to satisfy the needs of a paranoid user. Thus, the
rule of thumb is this: If you intend to remain untouchable on the Net, you must never, ever allow your
real name to fill that field within the /etc/passwd file.

A Few Words About Cookies

You have seen the message many times. You land on a WWW site and a dialog box appears. The
server at the other end says it wants to set a cookie. Most users have no idea what this means, so
they simply click the OK button and continue. Other users actually read the dialog box's contents
and get a little worried. (This is especially true when the cookie is going to be set for sometime into
the year 2000. The user may not be sure what a cookie is, but almost all users balk when that
cookie is going to hang around for 3 or 4 years.)
 

     TIP: If you have never seen such a dialog box, you need to set your options to warn
     you before cookies are being set. Personally, I prefer to at least be notified when
     anything is being written to my hard disk drive. You should watch all such activities
     closely, monitoring any code or other device that is arbitrarily forwarded to your
     machine.
 

What are cookies? The cookie concept is very much like getting your hand stamped at a dance club.
You can roam the club, have some drinks, dance, and even go outside to your car for a few minutes.
As long as the stamp is on your hand, you will not have to pay again, nor will your access be
restricted. But cookies go much further than this. They record specific information about the user, so
when that user returns to the page, the information (known as state information) can be retrieved.
The issue concerning cookies, though, isn't that the information is retrieved. The controversy is about
where the information is retrieved from: your hard disk drive.

Cookies (which Netscape calls persistent client state HTTP cookies) are now primarily used to
store options about each user as he browses a page. The folks at Netscape explain it this way:

     This simple mechanism provides a powerful new tool which enables a host of new types of
     applications to be written for Web-based environments. Shopping applications can now store
     information about the currently selected items, for fee services can send back registration
     information and free the client from retyping a user-id on next connection, sites can store
     per-user preferences on the client, and have the client supply those preferences every time
     that site is connected to.
 

     Cross Reference: The article from which the previous quote is excerpted, "Persistent
     Client State HTTP Cookies," can be found at
     http://home.netscape.com/newsref/std/cookie_spec.html.
 

To understand the way cookies work, please examine Figure 13.4.

Figure 13.4.
Setting cookies.

As you can see, when the remote server is contacted, it requests permission to set a cookie. (One
wonders why some sites set a cookie on their opening page. Just what state information are they
recording? You haven't specified any preferences yet, so there is essentially nothing to record.) Prior
to the setting of the cookie, however, the user is generally confronted with the advisory shown in
Figure 13.5.

Figure 13.5.
Cookie warning!
 

     TIP: Note that this advisory will only be shown if you choose this option (Warn on
     Cookie) in your preferences. In Netscape Navigator, this option can be toggled in the
     Network Preferences menu under the Protocols tab. In Microsoft Internet Explorer, it
     can be set in the Options menu under the Advanced tab.
 

Advocates of cookies insist that they are harmless, cannot assist in identifying the user, and are
therefore benign. That is not true, as explained by D. Kristol and L. Montulli in RFC 2109:

     An origin server could create a Set-Cookie header to track the path of a user through the
     server. Users may object to this behavior as an intrusive accumulation of information, even if
     their identity is not evident.(Identity might become evident if a user subsequently fills out a
     form that contains identifying information.)

I know many programmers who are exploring techniques for using cookies for user authentication.
This is disturbing. There has not been enough scrutiny of the privacy issues surrounding cookies, and
there needs to be some method developed to manage them. That is, perhaps some cookies are
desirable to a particular user and some are not. The user may visit certain sites regularly. If those
sites use cookie conventions, the user will unnecessarily be confronted with a cookie warning each
time he visits, unless that cookie remains on the drive. However, other cookies (from sites that the
user may never visit again) should be easily removed. This is also discussed in RFC 2109:

     User agents should allow the user to control cookie destruction. An infrequently used cookie
     may function as a "preferences file" for network applications, and a user may wish to keep it
     even if it is the least-recently-used cookie. One possible implementation would be an interface
     that allows the permanent storage of a cookie through a checkbox (or, conversely, its
     immediate destruction).

Briefly, to find the cookies on your hard disk drive, search for the file cookies.txt. This file will
contain a list of cookies and their values. It looks like this:

www.webspan.net    FALSE    /~frys    FALSE    859881600    worldohackf   2.netscape.com    TRUE    /    FALSE    946684799    NETSCAPE_ID
1000e010,107ea15f.adobe.com    TRUE    /    FALSE    946684799    INTERSE    207.171.18.182 6852855142083822www.ictnet.com    FALSE    /    FALSE    946684799    Apache    pm3a-4326561855491810745.microsoft.com    TRUE    /    FALSE    937422000
MC1    GUID=260218f482a111d0889e08002bb74f65.msn.com    TRUE    /    FALSE    937396800    MC1    ID=260218f482a111d0889e08002bb74f65comsecltd.com    FALSE    /    FALSE    1293753600    EGSOFT_ID    207.171.18.176-3577227984.29104071
.amazon.com    TRUE    /    FALSE    858672000    session-id-time    855894626.amazon.com    TRUE    /    FALSE    858672000    session-id  0738-6510633-772498

This cookie file is a real one, pulled from an associate's hard disk drive. You will see that under the
GUID, the leading numbers are an IP address. (I have added a space between the IP address and
the remaining portion of the string so that you can easily identify the IP. In practice, however, the
string is unbroken.) From this, you can see clearly that setting a cookie may involve recording IP
addresses from the target. Now, this does not mean that cookies are a major threat to your privacy.
Many JavaScript scripts (and Perl scripts) are designed to "get" your IP. This type of code also can
get your browser type, your operating system, and so forth. Following is an example in JavaScript:

 <script language=javascript>
     function Get_Browser() {
     var appName = navigator.appName;
     var appVersion = navigator.appVersion;
     document.write(appName + " " + appVersion.substring (0,appVersion.indexOf(" ")));
     }
</script>

This JavaScript code will get the browser and its version. Scripts like this are used at thousands of
sites across the Internet. A very popular one is the "Book 'em, Dan-O" script. This script (written in
the Perl programming language) will get the time, the browser, the browser's version, and the user's
IP.
 

     Cross Reference: The "Book 'em, Dan-O" script was written by an individual named
     Spider. It is currently available for download at Matt's Script Archive, at
     http://worldwidemart.com/scripts/dano.shtml.
 
 

     Cross Reference: One site that will get many of your environment variables,
     particularly if you use UNIX, is located at
     http://hoohoo.ncsa.uiuc.edu/cgi-bin/test-env. What is interesting is that it
     will catch both the PPP-based address (as in ppp32-vn074.provider.com) as well
     as your actual IP.
 

Also, nearly all Web server packages log access anyway. For example, NCSA HTTPD provides an
access log. In it, the IP address of the requesting party is logged. The format of the file looks like
this:

- - [12/Feb/1997:17:20:59 -0800] "GET /~user/index.html i HTTP/1.0" 200 449

The major difference between these devices and the cookie implementation, however, is that
cookies are written to a file on your hard disk drive. Many users may not be bothered by this, and in
reality, there is nothing threatening about this practice. For example, a cookie can only be read by
the server that set it. However, I do not accept cookies as a rule, no matter how persistent the
server may be at attempting to set one. (Some programmers provide for this process on every page,
hoping that eventually the user will tire of dealing with dialog boxes and simply allow the cookie to be
set.)

It is interesting to note that some clients have not been preconfigured to deny cookies. In these
instances, a cookie may be written to the drive without the user's consent, which is really the default
configuration, even for those browsers that support screening of cookies. Early versions of both
Netscape Navigator and Microsoft Internet Explorer shipped with the Deny Cookies checkbox
unchecked. Absentmindedness on the part of the vendors? Perhaps. If you have a problem denying
cookies, for whatever reason, there is an action you can undertake to prevent these items from being
written to your drive. One is to make the file cookies.txt read-only. Thus, when a foreign Web
server attempts to write to the file, it will fail.
 

     TIP: It has been reported that this can be done in MacOS by first deleting and then
     re-creating the cookie file and subsequently placing it into the Preferences folder.
 

I recommend denying cookies, not so much because they are an invasion, but because they leave a
trail on your own hard disk drive. That is, if you visit a page that you have been forbidden to access
and it sets a cookie, the evidence will be in cookies.txt. This breaks down to cache issues as
well: even if your cookies file is clean, your cache will betray you.
 

     NOTE: Although this is a well-known issue, new users may not be aware of it, so I
     will explain. To retrieve the sites you have most recently visited, type about:cache in
     the Open Location box in Netscape's Navigator. A new page will appear, showing
     Web pages you have recently visited. So, if you browse the Net at work when you are
     supposed to be performing your duties, you will want to kill that cache every few
     minutes or set its value to 0.
 

Currently, denying a cookie does not dramatically influence your ability to access a page, although
that may change in the future. At best, the cookie issue has assisted in heightening public awareness
that a remote Web server can cull your IP address and, in certain instances, your location, your
operating system, your browser, and so forth.
 

     NOTE: If you are uncomfortable with denying cookies from all sites, perhaps you
     should check out a program called Cookie Jar. Cookie Jar allows you to specify what
     servers you will accept cookies from. The program was written by Eric Murray, a
     member of the Sams technical editorial team. Cookie Jar is located at
     http://www.lne.com/ericm/cookie_jar/. The main amenity of Cookie Jar is
     convenience. Many sites require that you accept a cookie to access certain services.
     Cookie Jar can perform filtering for you.
 

Public Postings

We will now assume that no one knows who you are. They are about to find out, however, because
you are about to post a message to a Usenet newsgroup. From the moment you post a message to
Usenet, your name and e-mail address are fair game.

The Usenet news network is somewhat different from other forms of communication on the Internet.
For a start, it is almost entirely public, with a very few exceptions. Moreover, many Usenet news
newsgroups are archived--that is, the articles posted to such groups are bundled and stored for later
use. I have seen archived messages ranging back to 1992, some of which are reachable by WAIS,
FTP, Telnet, and other, antiquated interfaces.
 

     TIP: Note that these are private archives and have nothing to do with search engines.
     The big search engines generally archive Usenet messages for a few weeks only. In
     contrast, private archives (maintained by non-commercial, special interest groups),
     especially those that have listservers in addition to newsgroups, may be maintained for
     a long, long time.
 

Because these messages are kept, your e-mail address (and identity, because your identity can be
traced with it) has a shelf life. Hucksters like list brokers routinely tap such archives, searching for
leads--collections of e-mail addresses of persons who share a particular interest, such as all females
over 40 years of age who smoke a pipe, have an eye patch, and voted Republican in the last
election. If you think that this level of refinement is ludicrous, think again. Applying various search
spiders (and a number of personal robots), one can narrow the search to something that specific.

The first step in developing such a list is to capture e-mail addresses. To do this, any garden-variety
search engine will do, although AltaVista (altavista.digital.com) and DejaNews
(www.dejanews.com) have the most malleable designs. Even though these engines are well known
to most users, I am providing screen captures of their top-level pages, primarily for reference
purposes as I explain Usenet snooping.

Figure 13.6.
The top-level page of AltaVista.

AltaVista is one of the most powerful search engines available on the Internet and is provided as a
public service by Digital Equipment Corporation (DEC). It accepts various types of queries that can
be directed toward WWW pages (HTML) or Usenet postings. (The Usenet postings are archived,
actually. However, DEC reports that these are kept only for a period of "a few weeks.")

One key point about the AltaVista engine is that it was coded nicely. By enclosing strings in
quotation marks, you can force a case-sensitive, exact regex (regular expression) match. As a result,
you can isolate one page out of millions that contains the exact string you're seeking. Similarly, you
can isolate all Usenet postings made by a particular author. By taking each of those postings and
analyzing them, you can identify that person's chief interests. (Perhaps the person is a militia member,
for example.)

The DejaNews search engine is a very specialized tool. It is solely a Usenet robot/spider. The
DejaNews archive reportedly goes back to March 1995, and the management indicates that it is
constantly trying to fill gaps and get older articles into the database. It claims that it is working on
providing all articles posted since 1979. Figure 13.7 shows the top page of DejaNews.

Figure 13.7.
The top-level page of DejaNews.

DejaNews has some more advanced functions for indexing, as well. For example, you can
automatically build a profile on the author of a Usenet article. (That is, the engine will produce a list
of newsgroups that the target has posted to recently.)

Defeating the archiving of your Usenet messages on both AltaVista and DejaNews is relatively
simple--for direct posting, at least. Either in the X headers of your Usenet article or as the first line of
your article, issue the following string:

x-no-archive: yes

This will ensure that your direct postings made to Usenet will not be archived. This does not,
however, protect you from third-party postings that contain your e-mail address. For example, if you
belong to a mailing list and that list is archived somewhere on the WWW (or even at FTP sites),
your e-mail address is already compromised. If your e-mail address appears in a thread of significant
interest (and your reply was sufficiently enlightening), it is guaranteed that the entire thread (which
contains your address) will be posted somewhere. And it will be somewhere other than Usenet;
perhaps a WWW page or a Gopher server.

Let us continue to suppose that you have no knowledge of how Usenet indexing works. Let us
further assume that although your real name does not appear on Usenet postings, it does appear in
the /etc/passwd file on the UNIX server that you use as a gateway to the Internet. Now you are a
viable target. Here are some steps that will lead the snooping party not simply to your real name, but
to the front door of your home. The steps are as follows:

     1. The snooping party sees your post to Usenet. Your e-mail address is in plain view, but
     your name is not.

     2. The snooping party tries to finger your address, but as it happens, your provider prohibits
     finger requests from the void.

     3. The snooping party Telnets to port 25 of your server. There, he issues the expn command
     and obtains your real name.

Having gotten that information, the snooping party next needs to find the state in which you currently
reside. For this, he turns to the WHOIS service.

The WHOIS Service

The WHOIS service (centrally located at rs.internic.net) contains the domain registration
records of all Internet sites. This registration database contains detailed information on each Internet
site, including domain name server addresses, technical contacts, the telephone number, and the
address. Here is a WHOIS request result on the provider Netcom, a popular Northern California
Internet service provider:

NETCOM On-Line Communication Services, Inc (NETCOM-DOM)
   3031 Tisch Way, Lobby Level
   San Jose, California 95128
   US
   Domain Name: NETCOM.COM
   Administrative Contact:
      NETCOM Network Management  (NETCOM-NM)  dns-mgr@NETCOM.COM
      (408) 983-5970
   Technical Contact, Zone Contact:
      NETCOM DNS Administration  (NETCOM-DNS)  dns-tech@NETCOM.COM
      (408) 983-5970
   Record last updated on 03-Jan-97.
   Record created on 01-Feb-91.
   Domain servers in listed order:
   NETCOMSV.NETCOM.COM          192.100.81.101
   NS.NETCOM.COM                192.100.81.105
   AS3.NETCOM.COM               199.183.9.4

Here, the snooping party has discovered that the provider is in the state of California. (Note the
location at the top of the WHOIS return listing, as well as the telephone points of contact for the
technical personnel.) This information will help tremendously; the snooping party now proceeds to
http://www.worldpages.com/. WorldPages is a massive database with a design very similar to
the average White Pages. It holds the names, e-mail addresses, and telephone numbers of several
million Internet users. (See Figure 13.8 for a screenshot of the top-level page of WorldPages.)

Figure 13.8.
The top-level page of WorldPages.

At WorldPages, the snooping party funnels your real name through a search engine, specifying the
state as California. Momentarily, he is confronted with a list of matches that provide name, address,
and telephone number. Here, he may run into some trouble, depending on how common your name
is. If your name is John Smith, the snooping party will have to do further research. However, let us
assume that your name is not John Smith. Let's assume that your name is common, but not that
common. So the snooping party uncovers three addresses, each in a different California city: One is
in Sacramento, one is in Los Angeles, and one is in San Diego. How does he determine which one is
really you? He proceeds to the host utility.

The host utility (discussed briefly in Chapter 9, "Scanners") will list all the machines on a given
network and their relative locations. With large networks, it is common for a provider to have
machines sprinkled at various locations throughout a state. The host command can identify which
workstations are located where. In other words, it is generally trivial to obtain a listing of
workstations by city. These workstations are sometimes even named for the cities in which they are
deposited. Therefore, you may see an entry such as

chatsworth1.target_provider.com

Chatsworth is a city in southern California. From this entry, we can assume that
chatsworth1.target_provider.com is located within the city of Chatsworth. What remains for
the snooper is to reexamine your Usenet post.

By examining the source code of your Usenet post, he can view the path the message took. That
path will look something like this:

news2.cais.com!in1.nntp.cais.net!feed1.news.erols.com!howland.erols.net! Âix.netcom.com!news

By examining this path, the snooping party can determine which server was used to post the article.
This information is then coupled with the value for the NNTP posting host:

grc-ny4-20.ix.netcom.com

The snooping party extracts the name of the posting server (the first entry along the path). This is
almost always expressed in its name state and not by its IP address. For the snooping party to
complete the process, however, the IP address is needed. Therefore, he next Telnets to the posting
host. When the Telnet session is initiated, the hard, numeric IP is retrieved from DNS and printed to
STDOUT. The snooping party now has the IP address of the machine that accepted the original
posting. This IP address is then run against the outfile obtained by the host query. This operation
reveals the city in which the machine resides.
 

     TIP: If this information does not exactly match, the snooping party can employ other
     methods to get the location of the posting machine. One such technique is to issue a
     Traceroute request. When tracing the route to a machine that exists in another city, the
     route must invariably take a path through certain gateways. These are main switching
     points through which all traffic passes when going in or out of a city. Usually, these are
     high-level points, operated by telecommunication companies like MCI, Sprint, and so
     forth. Most have city names within their address. Bloomington and Los Angeles are
     two well-known points. Thus, even if the reconciliation of the posting machine's name
     fails against the host outfile, a Traceroute will reveal the approximate location of the
     machine.
 

Having obtained this information (and having now differentiated you from the other names), he
returns to WorldPages and chooses your name. Within seconds, a graphical map of your
neighborhood appears. The exact location of your home is marked on the map by a circle. The
snooping party now knows exactly where you live and how to get there. From this point, he can
begin to gather more interesting information about you. For example:

     The snooping party can determine your status as a registered voter and your political
     affiliations. He obtains this information at
     http://www.wdia.com/lycos/voter-records.htm.

     From federal election records online, he can determine which candidates you support and
     how much you have contributed. He gets this information from
     http://www.tray.com/fecinfo/zip.htm.

     He can also get your Social Security number and date of birth. This information is available at
     http://kadima.com/.

Many users are not bothered by this. Among those people, the prevailing attitude is that all such
information is available through sources other than the Internet. The problem is that the Internet
brings these sources of information together. Integration of such information allows this activity to be
conducted on a wholesale basis, and that's where the trouble begins.

It is now possible (using the techniques described here) to build models of human networks--that is,
it is now possible to identify all members of a particular class. It is also possible to analyze the
relationships between them. This changes the perspective for intelligence agencies.

Years ago, gathering domestic intelligence was a laborious process. It required some element,
however slim, of human intelligence. (Human intelligence here refers to the use of human beings to
gather information as opposed to machines or other, automated processes.) Thus, to get the
low-down on the Students for a Democratic Society, for example, intelligence agencies had to send
agents on foot. These agents had to mix with the crowd, record license plate numbers, or gather
names at a rally. Today, those methods are no longer necessary.

Today, the Internet provides a superb tool to monitor the public sentiment (and perhaps to identify
those who conspire to take up arms). In some respects, one might concede that this is good.
Certainly, if individuals are discussing violence or crime, and they contemplate these issues online, it
seems suitable that law-enforcement agencies can take advantage of this emerging technology.
However, it should be recognized here that the practice of building models of human networks via
the Internet violates no law. It amounts to free spying, without a warrant. Put more bluntly, we
Americans do often have big mouths. Some of us would do better to keep quiet.

Before I continue, I want to make one point clear: Complete anonymity on the Internet is possible,
but not legally. Given enough time, for example, authorities could trace a message posted via
anonymous remailer (although, if that message were chained through several remailers, the task
would be far more complex). The problem is in the design of the Internet itself. As Ralf Hauser and
Gene Tsudik note in their article "On Shopping Incognito":

     From the outset the nature of current network protocols and applications runs counter to
     privacy. The vast majority have one thing in common: they faithfully communicate end-point
     identification information. `End-point' in this context can denote a user (with a unique ID), a
     network address or an organization name. For example, electronic mail routinely
     communicates sender's address in the header. File transfer (e.g., FTP), remote login (e.g.
     Telnet), and hypertext browsers (e.g. WWW) expose addresses, host names and IDs of their
     users.

Indeed, the process starts at the very moment of connection. For example, workstations connected
to a network that is directly wired to the Net all have permanent addressing schemes. Certainly, an
Ethernet spoof will not carry when crossing the bridge to IP; therefore, fixed stations permanently
strung to the Internet will always have the same IP. And, short of the operator of such a workstation
getting root access (and altering the routing tables), there is little that can be done in this regard.

Similarly, the average user's IP is dependent solely upon his server. Consider the exchange that
occurs in a dial-up account. (See Figure 13.9.)

Figure 13.9.
A little case study: dynamic IP allocation.

Most servers are now running some form of dynamic IP allocation. This is a very simple but
innovative system. Examine the Ethernet arrangement to the right of Figure 13.9 (a garden-variety
rack of headless workstations). Each machine on that network can allocate a certain number of IP
addresses. Let's make it simple and say that each workstation can allocate 254 of them. Think of
each address as a spoke in a bicycle wheel. Let's also assume that the IP address for one of these
boxes is 199.171.180.2 (this is an imaginary address). If no one is logged on, we say that the
available addresses (on that box) range from 199.171.180.3 to 199.171.180.255.

As long as only a portion of these address are occupied, additional addresses will be allocated.
However, what if they are all allocated? In that case, the first one to be disengaged will be the next
available IP. That is, suppose they are all allocated and you currently occupy 199.171.180.210.
As soon as you disconnect (and if no one else does before the next call), the very next customer will
be allocated the address 199.171.180.210. It is a free slot (left free because you have
disconnected), and the next caller grabs it. The spokes of the wheel are again fully occupied.
 

     TIP: In practice, the process is more complex, involving more hardware and so forth.
     However, here we are just concerned with the address allocation, so I have greatly
     simplified the process.
 

This demonstrates that in dynamic IP allocation, you will likely have a different address each time
you connect. Many individuals who run illegal BBS systems on the Internet take advantage of this
phenomenon.
 

     NOTE: The term illegal here refers to those BBS systems that distribute unlawful
     software. This does not have to be warez (pirated software) either. Certain types of
     cellular cloning software, for example, are unlawful to possess. Distribution of such
     software will bring the authorities to your door. Likewise, "illegal" BBS activity can be
     where the operator and members engage in cracking while logged on. Lastly, those
     BBS systems that distribute child pornography are, quite obviously, illegal.
 

The dynamic allocation allows users to perform a little parlor trick of sorts. Because the IP is
different each time, an illegal BBS can be a moving target. That is, even if law-enforcement officials
suspect the activity being undertaken, they are not sure where it is happening without further
research.

Typically, this type of setup involves the perpetrators using a networked operating system (almost
always Linux or FreeBSD) that allows remote logins. (These logins may include FTP, Telnet,
Gopher, and so on. It is also fairly common to see at least sparse HTTP activity, although it is almost
always protected using htpasswd.) It is also common for the operator of such a board to request
that users use SSH, S/Key, or some other, secure remote-login software so that third parties cannot
snoop the activity there.

Typically, the operator connects using the networked operating system and, after having determined
the IP for the night, he mails out the network address to the members of the group. (This is usually an
automated process, run through a Perl script or some other shell language.) The mailed message
need be no more than a blank one, because all that is important is the source address.

For the brief period that this BBS is connected, it effectively serves as a shadowed server in the
void. No one would know of its existence unless they scanned for it. Most often, the operator will
kill both finger and the r services, therefore blocking the prying eyes of third parties from determining
who is logged to the server. Moreover, the operator has usually gained some privileged access to his
provider's network and, having done so, can obscure his presence in system logs.

For the individuals in these groups, relative anonymity is realized because, even if an outside party
later questions the sysad of the provider, the logs may be very sparse. Most system administrators
are reluctant to kill an account without adequate proof. True, the logs at any outside network would
show some activity and the IP it originated from, but that is not enough. If the system administrator
cannot say with certainty who perpetrated the activity, he has no case. Meanwhile, during the period
when users are logged in to this hidden server, they, at least, are shielded in terms of identity. They
can then Telnet back out of that machine (or connect to IRC) and from there, they have some level
of shielding. But what about the average Joe?

The average user does not implement such schemes. He connects using mostly client software, on
the IBM or Mac platform, and is not looking to provide services. The difference is considerable.
Certainly, anyone using the configuration described here has more options with regard to sending,
say, fakemail. Because that person controls the server (and the sendmail application is local), even a
simple message sent from the console will appear differently from one sent from a Windows client.
Such a message cannot be trusted, and only by reviewing the full headers can you reliably determine
where it came from.
 

     TIP: You will recall that in Chapter 9, I discussed this point. The technique for
     identifying the source of fakemail involves using Traceroute. Generally, the
     second-to-last listing in the Traceroute results will reveal the actual source. In other
     words, the second-to-last line will reveal the provider network, and from that you can
     deduce that the user was at least temporarily connected to that server. A discussion
     with the sysad at that location should give you the username--providing, of course, that
     you can convince the sysad that there is a reason for him to release such information.
 

My point is this: During the period when a shadowed server is up, those who log in from the void are
safe and hidden, but only as long as the operator of the box refuses to provide their identities.

For example, say a kid establishes such a box in California. His friends from Philadelphia connect to
the box and use it as a launching pad. From there, the folks from Philadelphia Telnet back out and
begin cracking some server in the void. Our boy in California may later have to answer for this
activity. However, if he has erased his logs (and keeps his mouth shut), the people from Philadelphia
will never be found. Which leads to this advice: If you run such a server, never, ever allow individuals
you do not know to use it. When you destroy the logs, you are sealing your own fate. These
individuals are using an IP address that can be traced to you (unless you have root access on your
provider's box). Thus, if you meet someone on IRC and he begs you for a shell account, it is best
that you refuse until you know him. Otherwise, it is you and not he who will suffer.

At any rate, because of the inherent design of the Internet, the IP address is a universal identification
index. It has to be, because without it, how could information be routed across the network?
Therefore, be advised that although you may change your mail address in Netscape Navigator or
other programs containing mail packages, this does not obscure your identity. True, inexperienced
users will be dumbfounded as to the origin of the message, but anyone familiar with UNIX can trace
the message right to its source.

I imagine that the majority of my readers are not criminals and simply want to keep their name out of
Usenet screens or mailing lists. However, for those inclined to break the law (who are scouring this
chapter for that one, single answer), I say this: To totally shield yourself from the law (and other,
interested parties), you will need these items:

     A cloned cellular telephone or other means of initiating a digital connection (seizing a circuit,
     perhaps)

     A laptop (loaded with either FreeBSD or Linux)

     Credit card numbers stolen from a clean source

     A PCICMA modem

     A reason for all this

Certain individuals are available for hire to perform various crimes over the Internet. When they
conduct their activity, this is how they do it. The credit card numbers are usually bought outright from
an underground, or a "clean," source; one that law enforcement can neither readily identify or reach.
Most of these are on microfiche, taken from a financial institution or other source that has a quantity
of numbers. (Note that only those individuals who are doing high-volume work will buy microfiche.
This is because using microfiche-based numbers is in itself a risk. Later analysis by law enforcement
will reveal that sets of numbers used may have or appear to have originated from the same source.)

Those involved in this activity generally explain that banks are poor sources for the numbers, as are
Internet service providers, car rental agencies, and retail chains. It is argued that the best source is
from mail-order lists or department store databases. These are the reasons:

     These lists contain many different types of credit cards, not just one.

     These card numbers belong to accounts that are underwritten by many institutions, not just
     one.

     The rightful owners of such credit cards live at locations sprinkled throughout the United
     States; therefore, the activity initially appears to be unconnected.

     Law-enforcement agents will initially be dumbfounded as to the seed source of the numbers,
     for all these reasons.

Having obtained the numbers, the next step is to choose a provider. Most individuals who do this on
a regular basis have lists of providers that allow "instant access," where you provide your vitals, your
credit card, your desired login, your password, and so forth. Within minutes, you are surfing the Net.

Using this technique, you can reliably obtain total anonymity for short periods of time, periods long
enough to perform the desired task. The only hope that authorities have of catching you is to elicit
corroborative testimony of a coconspirator, or if you establish a pattern of activity--for example, if
spend your nights breaking into machines owned or operated by security specialists who are also
talented hackers.
 

     NOTE: I have not suggested here that any reader undertake the action described here.
     If you do so, you do it at your own peril. These actions amount to crime--or, in fact, a
     series of crimes. Here, I have merely explained one technique, and no more. Neither I
     nor Sams Publishing advocate, support, or condone such activity.
 

For my more law-abiding readers (the majority, I hope), there are varying degrees of anonymity that
can be obtained. It depends upon why you want to hide and the sensitivity of the data you are
trafficking. It has been recognized that there are plenty of legitimate reasons for allowing anonymity
on the Internet. The following is excerpted from "Anonymity for Fun and Deception: The Other Side
of `Community'" by Richard Seltzer: Some communities require anonymity for them to be effective,
because without it members would not participate. This the case with Alcoholics Anonymous, AIDS
support groups, drug addiction support and other mutual help organizations, particularly when there
is some risk of social ostracism or even legal consequences should the identity of the members be
revealed.
 

     Cross Reference: "Anonymity for Fun and Deception: The Other Side of
     `Community'" by Richard Seltzer can be found on the Web at
     http://www.samizdat.com/anon.html.
 

This is a recurring theme in the now-heated battle over Internet anonymity. Even many members of
the "establishment" recognize that anonymity is an important element that may preserve free speech
on the Internet--not just here, but abroad. This issue has received increased attention in legal circles.
An excellent paper on the subject was written by A. Michael Froomkin, a lawyer and prominent
professor. In "Anonymity and Its Enmities," Froomkin writes

     Persons who wish to criticize a repressive government or foment a revolution against it may
     find remailers invaluable. Indeed, given the ability to broadcast messages widely using the
     Internet, anonymous e-mail may become the modern replacement of the anonymous handbill.
     Other examples include corporate whistle-blowers, people criticizing a religious cult or other
     movement from which they might fear retaliation, and persons posting requests for information
     to a public bulletin board about matters too personal to discuss if there were any chance that
     the message might be traced back to its origin.
 

     Cross Reference: "Anonymity and Its Enmities" by Professor Froomkin is an
     excellent source for links to legal analysis of Internet anonymity. Especially for
     journalists, the paper is an incredible resource. It can be found on the Web at
     http://warthog.cc.wm.edu/law/publications/jol/froomkin.html.
 

However, not everyone feels that anonymity is a good thing. Some people believe that if anonymity is
available on the Internet, it amounts to nothing but anarchy. Here is a rather ironic quote, considering
the source is Computer Anarchy: A Plea for Internet Laws to Protect the Innocent by Martha
Seigel:

     People need safety and order in cyberspace just as they do in their homes and on the streets.
     The current state of the Internet makes it abundantly clear that general anarchy isn't working.
     If recognized governments don't find a way to bring order to the growing and changing
     Internet, chaos may soon dictate that the party is over.

You may or may not know why this quote is so incredibly ironic. The author, Martha Seigel, is no
stranger to "computer anarchy." In her time, she has been placed on the Internet Blacklist of
Advertisers for violating network policies against spamming the Usenet news network. The following
is quoted from the docket listing on that blacklist in regards to Cantor & Seigel, Ms. Seigel's law
firm:

     The famous greencard lawyers. In 1994, they repeatedly sent out a message offering their
     services in helping to enter the U.S. greencard lottery to almost all Usenet newsgroups. (Note
     in passing: they charged $100 for their service, while participating in the greencard lottery is
     free and consists merely of sending a letter with your personal information at the right time to
     the right place.) When the incoming mail bombs forced their access provider to terminate their
     account, they threatened to sue him until he finally agreed to forward all responses to them.
 

     Cross Reference: The Internet Blacklist can be found on the Web at
     http://www.cco.caltech.edu/~cbrown/BL/.
 

I should mention here that Cantor and Seigel are the authors of How To Make A Fortune On The
Information Superhighway (HarperCollins, 1994). For Internet marketers, this book is
purportedly a must-read.

I also understand that a new book by Seigel, How to Make a Fortune on the Internet
(HarperCollins), is forthcoming.

However, all this may be academic. As we move toward a cashless society, anonymity may be built
into the process. In this respect, at least, list brokers (and other unsavory information collectors) had
better do all their collecting now. Analysis of consumer buying habits will likely become a thing of the
past, at least with relation to the Internet. The majority of electronic payment services being
developed (or already available) on the Internet include anonymity as an inherent part of their design.
 

     Cross Reference: Dan Fandrich, a prominent programmer and computer enthusiast in
     British Columbia, has compiled a comprehensive list of such systems. That list is
     located at http://vanbc.wimsey.com/~danf/emoney-anon.html. Of the
     systems Fandrich researched, here are a few:

          DigiCash
          Café
          CyberCash
          NetBank/NetCash
          First Virtual
 
 

Fandrich's research demonstrates a few significant points. Some systems claim to offer "total"
anonymity, but they really don't. He observes, for example, that many systems keep logs of the
activity. This represents one important issue. While individuals are concerned with their privacy, and
banks would like to ensure that privacy, some medium must be reached. Because if there is total
anonymity, how can crimes be adequately investigated? Certainly, new fraud schemes will arise as a
result of these new technologies. For example, a technique is already known for defeating the
security of smartcards. (I will not be printing that here, I'm afraid.)

In short, complete anonymity on the Internet is becoming less and less easy to lawfully obtain.
However, advanced research in the area of anonymous payment schemes will probably turn that
around dramatically in the next five years. For, while government agencies are circumspect about
Internet anonymity, the coming age of Internet commerce almost demands it. That is where the
research is going at the moment, and there is no indication of that trend changing in the near future.

Summary

This chapter discusses a variety of ways you can conceal your identity, including using utilities such
as finger, the r commands, and Master Plan. The issue of cookies is addressed. Finally, the issue of
anonymity is discussed as it relates to Usenet postings and the WHOIS service.

Resources

Privacy & Anonymity on the Internet FAQ. L. Detweiler. Many sources on privacy and
anonymity on the Internet. A must for users new to identity issues on the Net.

     http://www.prz.tu-berlin.de/~derek/internet/sources/privacy.faq.02.html

Anonymous Remailer FAQ. Andre Bacard. A not-too-technical description of anon remailers,
how they work, and where they can be found.

     http://www.well.com/user/abacard/remail.html

Note: Bacard is also the author of Computer Privacy Handbook ("The Scariest Computer Book
of the Year").

The Anonymous Remailer List. Raph Levien. Locations of anonymous remailers on the Internet.

     http://www.cs.berkeley.edu/~raph/remailer-list.html

How-To Chain Remailers. Alex de Joode. A no-nonsense tutorial on how to chain remailers and,
in doing so, send a totally anonymous message.

     http://www.replay.com/remailer/chain.html

Privacy on the Internet. David M. Goldschlag, Michael G. Reed, and Paul F. Syverson: Naval
Research Laboratory Center For High Assurance Computer Systems. A good primer that covers all
the aspects discussed in this chapter.

     http://www.itd.nrl.navy.mil/ITD/5540/projects/onion-routing/inet97/index.htm

Anonymous Connections and Onion Routing. David M. Goldschlag, Michael G. Reed and Paul
F. Syverson: Naval Research Laboratory Center For High Assurance Computer Systems.
PostScript. Presented in the Proceedings of the Symposium on Security and Privacy in Oakland,
Calif., May 1997. A quite detailed analysis of anonymous connections and their resistance to tracing
and traffic analysis. (Also discusses vulnerabilities of such systems. A must read.)

     http://www.itd.nrl.navy.mil/ITD/5540/projects/onion-routing/OAKLAND_97.ps

Special Report: Privacy in the Digital Age. Susan Stellin. CNET article containing resources on
privacy on the Internet.

     http://www.cnet.com/Content/Features/Dlife/Privacy/

The Electronic Frontier Foundation. Comprehensive sources on electronic privacy.

     http://www.eff.org/

The Electronic Privacy Information Center (EPIC). Civil liberties issues. This site is
indispensable in getting legal information on privacy and anonymity on the Internet and elsewhere.

     http://epic.org/

Computer Professionals for Social Responsibility--CPSR. A group devoted to discussion
about ethics in computer use.

     http://snyside.sunnyside.com/home/

The Anonymizer. A site that offers free anonymous surfing. The application acts as a middleman
between you and the sites you surf. Basically, it is a more complex proxying service. It allows
chaining as well, and your IP is stripped from their logs.

     http://www.anonymizer.com/

Articles and Papers

On Shopping Incognito. R. Hauser and G. Tsudik. Second USENIX Workshop on Electronic
Commerce, November 1996.

     http://www.isi.edu/~gts/paps/hats96.ps.gz

The Anonymous E-mail Conversation. Ceki Gulcu. Technical Report, Eurecom Institute. June
1995.

Control of Information Distribution and Access. Ralf C. Hauser. Technical Report, Department
of Computer Science, University of Zurich. September 1995.

Internet Privacy Enhanced Mail. Stephen T. Kent. Communications of the ACM, vol.36 no.8,
August 1993.

Certified Electronic Mail. Alireza Bahreman, J. D. Tygar. 1994.

     ftp://ftp.cert.dfn.de/pub/pem/docs/CEM.ps.gz

E-Mail Security. Dr. John A. Line. UKERNA Computer Security Workshop, November 15-16,
1994.

     ftp://ftp.cert.dfn.de/pub/pem/docs/UKERNA-email-security.ps.gz

Anonymous Internet Mercantile Protocol. David M. Kristol, Steven H. Low, and Nicholas F.
Maxemchuk. 1994.

     http://julmara.ce.chalmers.se/Security/accinet.ps.gz

Anonymous Credit Cards. Steven Low and Nicholas F. Maxemchuk and Sanjoy Paul. 1994.

     http://julmara.ce.chalmers.se/Security/anoncc.ps.gz

NetCash: A Design for Practical Electronic Currency on the Internet. Gennady Medvinsky
and B. Clifford Neuman. 1993.

     http://julmara.ce.chalmers.se/Security/netcash2.ps.gz

Electronic Fingerprints: Computer Evidence Comes of Age. Anderson, M.R., Government
Technology Magazine, November 1996.

Achieving Electronic Privacy. David Chaum. Scientific American, pp. 96-101, August 1992.

Erased Files Often Aren't. Anderson, M.R., Government Technology Magazine, January
1997.

FBI Seeks Right to Tap All Net Services. Betts, M. ComputerWorld, Vol. XXVI, No. 23,
June 8, 1992.
 

E-Mail any questions, comments or deaththreats to:

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Copyright © AcidMeister...

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Disclaimer:
 
 
 
 

This is for Educational purposes only it should not be used as a guide to

cause havoc or to hack. He He He, good luck!!! And don't get caught.  I

would hate to see you in a cell with your 300 pound Bruno The Gay Ax

murderer. He He He.