PARASITIC COMPUTING: PROBLEMS AND ETHICAL CONSIDERATION

International Journal of Advance Research, IJOAR .org
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Volume 1, Issue 11, November 2013, Online: ISSN 2320-9194
PARASITIC COMPUTING: PROBLEMS AND ETHICAL
CONSIDERATION
Abstract
Parasitic computing is programming technique where a program in normal authorized interactions with
another program manages to get the other program to perform computations of a complex nature. It is, in a sense, a
security exploit in that the program implementing the parasitic computing has no authority to consume resources
made available to the other program.The paper takes a look at the ethical issues of parasitic computing and suggest a
look into the current operation of the internet TCP/IP.
Keyword:
parasitic computing, internet, TCP/IP

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Introduction
Parasitic computing is programming technique where a program in normal authorized
interactions with another program manages to get the other program to perform computations
of a complex nature. It is, in a sense, a security exploit in that the program implementing the
parasitic computing has no authority to consume resources made available to the other
program.
In this model, which we call `parasitic computing’; one machine forces target computers to
solve a piece of a complex computational problem merely by them in standard
communication. Consequently, the target computers are unaware that they have performed
computation for the benefit of a commanding node. As experimental evidence of the principle
of parasitic computing, we harness the power of several web servers across the globe, which-
unknown to them-work together to solve an NP complete problem. Unlike `cracking'
(breaking into a computer) or computer viruses, however, parasitic computing does not
compromise the security of the targeted servers, and accesses only those parts of the servers
that have been made explicitly available for Internet communication.
Like the “S e a r c h f o r E x t r a t e r r e s t r i a l I n t e l l i g e n c e ”
SETI@home project Philips(1999), parasitic computing decomposes a complex problem into
computations that can be evaluated independently and solved by computers connected to the
Internet; unlike the SETI project, however, i T h e d i s t r i b u t e d
c o m p u t i n g u t i l i z e d i n S E T I i n v o l v e s
v o l u n t e e r s f r o m a r o u n d t h e w o r l d w h o a l l o w
t h e i r l o c a l c o m p u t e r s t o b e u s e d f o r o n g o i n g
a n a l y s i s o f v a s t a m o u n t s o f d a t a o b t a i n e d
f r o m a r a d i o t e l e s c o p e c o n s t a n t l y s c a n n i n g
t h e h e a v e n s . S E T I a l l o w s a n y o n e w i t h a
c o m p u t e r a n d I n t e r n e t c o n n e c t i o n t o
d o w n l o a d s o f t w a r e t h a t w i l l r e a d a n d
a n a l y z e s m a l l p o r t i o n s o f t h e a c c u m u l a t e d
d a t a . I n e f f e c t , S E T I h a s c r e a t e d a s u p e r
c o m p u t e r f r o m m i l l i o n s o f i n d i v i d u a l
c o m p u t e r s w o r k i n g i n c o n c e r t . i t does so without the
knowledge of the participating servers.(Robert et al,2003)
This is a type of distributed computing technique known as parasitic computing invented by
computer scientists of the University of Notre Dame and questions its practice ethically. In
August 2001, four researchers at the University of Notre Dame – Albert‐László Barabási,
Vincent W. Freeh, Hawoong Jeong and Jay B. Brockman invented a very sophisticated
computing technique known as parasitic computing based upon this behavior of TCP/IP
(Barabási, Freeh, Jeong, & Brockman, 2001). A reliable communication over internet via
TCP/IP is a complex process and requires a significant amount of computation to validate the
integrity of the datagram being sent and received between two nodes. The integrity of a data
segment is maintained by validating the result of certain operations on the bytes of 16‐bit
Checksum field in its TCP packet. Figure below displays a TCP pseudo‐header with 16 bit
checksum field starting at bit offset 224.

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TCP checksum function
C h e c k s u m i s t h a t p a r t o f T C P l a y e r o p e r a t i o n
t h a t i s r e s p o n s i b l e f o r i n s u r i n g i n t e g r i t y o f
p a c k e t d a t a b e i n g s e n t o v e r t h e I n t e r n e t .
B e f o r e a p a c k e t i s r e l e a s e d t o t h e I P l a y e r
( s e e F i g . 1 ) o f t h e s e n d i n g c o m p u t e r , T C P
d i v i d e s t h e p a c k e t i n f o r m a t i o n i n t o a s e r i e s
o f 1 6 - b i t w o r d s a n d t h e n c r e a t e s a o n e ‟ s
c o m p l e m e n t b i n a r y s u m o f t h e s e w o r d s . T h e
r e s u l t i n g s o - c a l l e d “ c h e c k s u m ” v a l u e i s a
u n i q u e
r e p r e s e n t a t i o n o f t h e t o t a l i t y o f i n f o r m a t i o n
i n t h a t p a c k e t . T h e b i t - w i s e b i n a r y
c o m p l e m e n t o f
t h i s c h e c k s u m i s t h e n s t o r e d i n t h e T C P
h e a d e r b e f o r e t h e p a c k e t i s s e n t . W h e n t h e
p a c k e t
a r r i v e s a t t h e r e c e i v i n g c o m p u t e r , t h e T C P
l a y e r t h e r e p e r f o r m s i t s o w n b i n a r y s u m o f
a l l t h e
i n f o r m a t i o n i n t h e p a c k e t i n c l u d i n g t h e
c h e c k s u m c o m p l e m e n t . I f t h e p a c k e t w a s
r e c e i v e d
w i t h o u t c o r r u p t i o n , t h e r e s u l t a n t s u m s h o u l d
b e a 1 6 - b i t v a l u e w i t h a l l b i t s e q u a l t o 1 s i n c e
t h e
o r i g i n a l c h e c k s u m ( i . e . , t h e t o t a l a r r i v e d a t
b y t h e s e n d i n g c o m p u t e r ) a n d i t s
e x a c t c o m p l e m e n t
w o u l d b e a d d e d t o g e t h e r f o r m i n g a u n i t a r y
v a l u e ( B a r a b a s i , e t a l . , 2 0 0 1 ) . I f t h i s o c c u r s ,
t h e p a c k e t i s r e t a i n e d a s g o o d a n d i s p a s s e d
t o t h e a p p l i c a t i o n l a y e r f o r a c t i o n ; i f n o t , t h e
p a c k e t i s d r o p p e d a n d T C P w a i t s f o r a p r e -
a r r a n g e d r e t r a n s m i s s i o n o f t h e p a c k e t b y t h e
s e n d i n g c o m p u t e r . F r e e h ( 2 0 0 2 ) i n d i c a t e s ,
t h e T C P c h e c k s u m f u n c t i o n p e r f o r m e d b y
t h e r e c e i v i n g
c o m p u t e r i s , i n e s s e n c e , a f u n d a m e n t a l
“ a d d - a n d - c o m p a r e ” p r o c e d u r e , w h i c h f o r m s
t h e b a s i s
f o r a n y o t h e r B o o l e a n o r a r i t h m e t i c
o p e r a t i o n . A s a c o n s e q u e n c e , T C P c a n b e
e x p l o i t e d t o
p e r f o r m c o m p u t a t i o n s w i t h o u t ” i n v a d i n g ”
( i . e . , h a c k i n g o r c r a c k i n g i n t o ) t h o s e s y s t e m s
i n d u c e d t o p a r t i c i p a t e ( B a r a b a s i , e t . a l , 2 0 0 1 ;

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F r e e h , 2 0 0 2 ) . I n t h i s s e n s e , t h e n , p a r a s i t i c
c o m p u t i n g i s a “ n o n - i n v a s i v e ” f o r m o f c o v e r t
e x p l o i t a t i o n t h a t d o e s n o t p e n e t r a t e b e y o n d
t h e T C P / I P l a y e r s o f t h e h o s t . T h i s
d i f f e r e n t i a t e s p a r a s i t i c c o m p u t i n g f r o m t h e
o t h e r m e t h o d s d e s c r i b e d a b o v e f o r
c a p i t a l i z i n g o n I P - r e l a t e d v u l n e r a b i l i t i e s .
Fig.1
Literature review
How communication over internet via TCP/IP works
Consider a scenario where a user is trying to visit a website. When user informs a browser the
website URL (uniform resource locator), the browser opens a transmission control protocol
(TCP) connection and connects to the web server.
After establishing this connection, browser issues a hyper‐text transmission protocol (HTTP)
request via already opened TCP connection. This TCP message is then carried to the
destination (web server) via internet protocol (IP). In this process of transmitting message
from source (user) to destination, IP might break entire message into several pieces
commonly addressed as TCP packets. These packets are then transmitted to the destination IP
address via different routes. Once the destination receives all packets, a response is returned
to the source via the same TCP channel. The original message is then reassembled
via consecutive steps involving TCP and IP and is interpreted as HTTP request. After that,
the
web server sends a response (webpage HTML) back to the user (CISCO). Thus, even such a
simple communication over internet requires significant amount of computation at all
network stages and only cooperation and trust between all involved parties can guarantee a
successful communication over internet.

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In parasitic computing, this trust based relationship of machines connected to the network is
exploited to make other machines perform a certain mathematical operations on certain data
without an authorization. Albert‐László, Vincent, Hawoong and Jay used a parasitic computer
to solve the well known NP‐complete satisfiability problem, by engaging various web servers
physically located in North America, Europe, and Asia, each of which unknowingly
participated in the experiment Babarasi etal,2001.
Like SETI@home project, parasitic computing decomposes a problem into several small
problems which are mutually exclusive and can be solved independently via machines
connected to the network. Parasitic computing can be a very effective technique when it
comes to solve NP Complete problems such as Circuit SAT, 3 SAT, etc.
These problems are currently considered as some of world’s most complex and time
consuming problems. These problems generally have a set of solutions which itself is a
subset of a set of possible solutions.
This behaviour can be described as the following:
S ⊂ {s1,s2,s3...sn}, n>0
Although any possible solution to such problems can be verified quickly, there is no known
efficient way to identify a solution in the first place. In fact, the most notable characteristic
for such problem is that there is no fast solution. The time required to solve such problem is
exponentially proportional to the size of the problem. So, as the size of the problem grows,
the time required to find all solutions of the problem grows exponentially. In fact, time
required to solve a moderately large NP‐Complete problem can easily reach billions if
nottrillions of years using any kind of modern computing technology we have available
today. For this reason, even just determining whether there is a fast solution to such problems
or not is one of the principal unsolved problems of computer science.
Methodology
Two computers communicating over the Internet, under disguise of a standard
communications session. The first computer is attempting to solve a large and extremely
difficult 3-SAT problem; it has decomposed the original 3-SAT problem in a considerable
number of smaller problems. Each of these smaller problems is then encoded as a relation
between a checksum and a packet such that whether the checksum is accurate or not is also
the answer to that smaller problem. The packet/checksum is then sent to another computer.
This computer will, as part of receiving the packet and deciding whether it is valid and well-
formed, create a checksum of the packet and see whether it is identical to the provided
checksum. If the checksum is invalid, it will then request a new packet from the original
computer. The original computer now knows the answer to that smaller problem based on the
second computer's response, and can transmit a fresh packet embodying a different sub-
problem. Eventually, all the sub-problems will be answered and the final answer easily
calculated.

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Fig 2.How parasitic computing works
F i g u r e 1 . L a y e r s o f t h e T C P / I P
p r o t o c o l . A d a p t e d f r o m
S t e v e n s ( 1 9 9 4 ) .

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Figure 3.
Figure 2 describes how parasitic computing works. As described in figure 3.1, the parasitic
computer starts the process by transmitting specially generated messages to number of
targeted web servers consisting of arithmetic and logic unit (ALU) and a network interface
(NIF). The packet carrying one of possible solutions to the problem is inserted into the IP
level bypassing the parasitic node’s TCP. This can be seen in figure 3.2. The parasitic
computer generates a message in such a way that if the solution is not valid, it will fail the
TCP checksum on the destination machine and the packet will be dropped. But in the case
when the solution is correct, it will be propagated to the HTTP layer via TCP. Since it is a
behavior of a web server to respond to any requests coming to an HTTP layer regardless of
whether it understands the request or not, the web server will send a response back to the
parasitic computer that it has received an HTTP request Mujal(2010).
Thus the parasitic computer sends out a message for each possible solution as described in
figure 3.1 with black arrow, it only receives responses back from the server when the possible
solution is a one of the actual solutions of the problem. This is displayed with a red arrow in
the figure 3.1

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Ethical considerations
Worms, Viruses, and Trojan Horses
Exploitation of computing resources has taken many forms over the years, some
more malicious than others. Perhaps the most notorious examples are those involving what is
called “malware,” short for malicious software, designed to damage or disrupt a system
(Wiggins, 2001). Malware often takes the form of worms, viruses or Trojan horses, problems
that have become all too common in recent years and do not need to be explored further here.
IP-related Vulnerabilities
W i t h t h e a d v e n t o f n e t w o r k i n g , a n d t h e
a t t e n d a n t i n c r e a s e i n e m a i l u s a g e , m a n y
o t h e r
m e t h o d s b e c a m e a v a i l a b l e f o r g a i n i n g
u n a u t h o r i z e d a c c e s s t o c o m p u t i n g
r e s o u r c e s . W h i l e
e m a i l s t i l l m a y b e t h e m o s t c o m m o n m e t h o d
u s e d t o a c h i e v e t h e s p r e a d o f m a l w a r e
( W i g g i n s ,
2 0 0 1 ) , c e r t a i n f o r m s o f c o v e r t e x p l o i t a t i o n
a s s o c i a t e d w i t h v u l n e r a b i l i t i e s i n t h e T C P / I P
p r o t o c o l h a v e b e e n k n o w n f o r s o m e t i m e .
I P s p o o f i n g , d e n i a l s o f s e r v i c e , a n d c o v e r t
c h a n n e l s . E a c h r e p r e s e n t s e x p l o i t a t i o n o f t h e
“ t r u s t ” r e l a t i o n s h i p s B a r a b a s i e t a l . ( 2 0 0 1 )
d e s c r i b e a s b e i n g i n h e r e n t i n t h e T C P / I P
p r o t o c o l .
IP spoofing, a s d e s c r i b e d b y V e l a s c o i s a m e t h o d
w h e r e b y a p r o s p e c t i v e i n t r u d e r
i m p e r s o n a t e s a “ t r u s t e d ” m e m b e r o f a
n e t w o r k b y d i s c o v e r i n g i t s I P a d d r e s s a n d
t h e n
c o n s t r u c t i n g n e t w o r k p a c k e t s t h a t a p p e a r t o
h a v e o r i g i n a t e d f r o m t h i s s o u r c e . i n t r u d e r s
h a v e u s e d t h i s t e c h n i q u e t o e s t a b l i s h
c o m m u n i c a t i o n s w i t h r e m o t e c o m p u t e r s ,
t h e r e b y p o t e n t i a l l y “ s p o o f i n g ” t h e m i n t o
f u r t h e r v u l n e r a b i l i t i e s a n d / o r u n a u t h o r i z e d
a c c e s s .
Denials of DoS) i n v o l v e m a l i c i o u s a t t e m p t s t o
d e g r a d e o r d i s r u p t t h e a c c e s s o f n e t w o r k

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m e m b e r s t o a p a r t i c u l a r h o s t b y c o n s u m i n g
t h e T C P / I P r e s o u r c e s o f t h e h o s t o r t h e
b a n d w i d t h
o f t h e n e t w o r k i t s e l f . D e n i a l o f s e r v i c e
u s u a l l y e x p l o i t T C P / I P t r u s t a n d a l s o n o r m a l l y
i n v o l v e s o m e e f f o r t t o c o n c e a l t h e i d e n t i t y o f
t h e p e r p e t r a t o r .
B y t h e i r o w n a d m i s s i o n , B a r a b a s i e t a l .
( 2 0 0 1 ) w e r e a w a r e o f t h e e t h i c a l i s s u e s
i n v o l v e d i n t h e i r d e m o n s t r a t i o n o f p a r a s i t i c
c o m p u t i n g . O n t h e p r o j e c t w e b s i t e t h e y
s t a t e :
" P a r a s i t i c c o m p u t i n g r a i s e s i m p o r t a n t
q u e s t i o n s a b o u t t h e o w n e r s h i p o f t h e
r e s o u r c e s c o n n e c t e d t o t h e I n t e r n e t a n d
c h a l l e n g e s c u r r e n t c o m p u t i n g p a r a d i g m s
R o b e r t ( 2 0 0 3 )
Since most of the computers connected to the network will be using TCP/IP, the resources
available to the parasitic computer are virtually unlimited and almost all of the computer can
be exploited. Furthermore, there is a very high possibility that servers can allocate their
valuable CPU cycles to do the processing commanded by the parasitic node thus degrading
overall performance of the applications running on the server and access efforts of the normal
application user similar to that in the Denial of Service attack (DoS). Ganti & Xiao,
2008).
In order for this technique to be widely accepted, potential users need to answer some
important ethical questions. the speed at which this technique is capable of solving
NP‐Complete problems is thrilling! But what about the possibility of a DoS (unintentional or
intentional) attack as discussed above? Another ethical questions like what if terrorists gain
their expertise on this technique? But the final question I would like to ask is:
just like we patch security holes in our applications, is this possibly a time to rethink a better
and more secured protocol for communication over the internet? Shouldn’t the security of
underlying internet protocols used by billions of users worldwide have equal priority for its
updates and patches if not higher than any of normal applications?
U n d e r t h e r u b r i c o f I n t e r n e t E t h i c s a r e
b a s i c a l l y v a r i a n t s o f o l d e r e t h i c a l i s s u e s ( e . g . ,
1 . T h e f t
2 . C o p y r i g h t i n f r i n g e m e n t
3 . I n v a s i o n o f p r i v a c y ) d i s g u i s e d i n m o d e r n -
d a y ( i . e . , e l e c t r o n i c o r d i g i t a l )
c l o t h i n g ( R o b e r t , 2 0 0 3 )
T h e e t h i c a l “ g r a y a r e a ” h e r e a r i s e s f r o m t h e
f a c t t h a t t h e s p e c i f i c h o s t r e s o u r c e s t a r g e t e d
b y t h e p a r a s i t e a l r e a d y w e r e p a r t o f t h e
“ p u b l i c d o m a i n ” b y v i r t u e o f b e i n g a t t a c h e d
t o t h e I n t e r n e t . M o r e o v e r , t h e s e r e s o u r c e s

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w e r e n o t i n s t i g a t e d t o d o a n y t h i n g m a l i c i o u s
o r e v e n o u t o f t h e o r d i n a r y . H o w e v e r , t h e
u s e s t o w h i c h t h e h o s t r e s o u r c e s w e r e p u t
b y t h e p a r a s i t e c l e a r l y w e r e n o t s a n c t i o n e d
i n a n y e x p l i c i t w a y b y t h e h o s t o w n e r s .
In a white paper published by the Computer Ethics Institute, Barquin (1992) presented
what he called the “Ten Commandments of Computer Ethics,” which amounts to a list of
moral imperatives to guide ethical behavior related to the use of computing and information
technology resources. These guidelines have become fairly well known and have been
endorsed by other professional societies (e.g., Computer Professionals for Social
Responsibility, 2001). Barquin’s “commandments” overlap with similar strictures contained
in a statement published by the Association for Computing Machinery entitled the “ACM
Code of Ethics and Professional Conduct” (Association for Computing Machinery, 1992).
For purposes of the present discussion, certain of Barquin’s “commandments” appear directly
relevant to the ethics of parasitic computing.
Thou shalt not use a computer to harm others or interfere with their computer work
These imperatives, abstracted from Commandments 1 and 2, clearly position as unethical
any form of “malware” or other type of covert exploitation of computer resources with
harmful purpose or consequences. Benign forms of exploitation without mal-intent, like the
Barabasi et al. (2001) demonstration of parasitic computing, would seem under this mandate
to be an instance of “no harm, no foul.” One difficulty here, however, lies with the
assessment of harm.
Directly harmful effects to a user as a result of someone else’s covert exploitation are one
thing, but indirect consequences may be quite another.
Conclusion
We can’t deny patch security holes in our applications, is this possibly a time to rethink a
better of transmitting information and more secured protocol for communication over the
internet.
References
1.Parasitic Computing by Munjal Patel,January 30, 2010
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3. Phillips, D. T. (1999, May 23). ET, phone SETI@home! Retrieved January 20, 2010,
from NASA: http://science.nasa.gov/newhome/headlines/ast23may99_1.htm
4. “Parasitic Computing”Seminar by:Kunal Goswami 05IT6006

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5. Ganti, R. K., & Xiao, L. (2008). Detection of Parasitic Computing. Indiana: University of
Notre Dame.
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C o n d u c t
1 2 . B a r q u i n , R . C . ( 1 9 9 2 ) . I n p u r s u i t o f a „ t e n
c o m m a n d m e n t s ‟ f o r c o m p u t e r e t h i c s .
C o m p u t e r
E t h i c s I n s t i t u t e

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