Parasitic Computing

Parasitic Computing

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  PARASITIC COMPUTING Jothiraj.S 111712205039
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  INTRODUCTION  During packagetransfer across the internet message can be corrupted. TCP contains a checksum that provides some data integrity of the message.  Sender compute checksum and transmits that with message. The receiver also compute the checksum and if does not agree with the sender’s then the message was corrupted and discarded. The Abstract discusses the technical aspects of what has already been carried out and the related issues.
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  DEFINITION Parasitic computing isa technique in which one computer or server links to other servers and uses that equipment to provide computation capacity. It is normally not considered hacking, or theft of computer services, because the program does not defeat any locks or safeguards on the other equipment. Rather, a legitimate message can be delivered to the other computers, and they will provide computing capacity without any breach of security.
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  DETAILS OF PARASITICCOMPUTING  Parasitic computing is a concept by which one can use the resources of machines that are connected on the Internet.  This technology exploits open Internet protocols to use the resources of remote machines.  As the name suggests, the machine that requires the services of others does not need to be authorized by the latter.  Any machine, which is connected to the Internet, has to carry out minimum processing of any packet they receive without any authorization.  This concept is exploited by parasitic computing in order to make use of computing powers of remote machines and web servers all around the globe. So one cannot really stop their machines from being utilized in this manner.
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  IMPLEMENTATION USING TCP Sending a message over an internet is a very sophisticated process as the message is processed across many layers from HTTP then to TCP then to IP layer, going through data link layer finally to the physical layer and in the same manner the message is constructed back at the destination.  To implement this concept of parasitic computing we can choose to exploit processing theoretically any of these layers but below TCP layer it is not very beneficial.
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  • Till nowthere has been only one implementation, which has exploited this concept of parasitic computing. Idea is to use some feature of the protocol in such a manner that remote machines respond to the request unknowingly that they are involved in solving a complex problem and they believe that they are responding to a simple application request over TCP connection. • The main target problems for such distributed environments are NP-complete problems i.e. non-deterministic polynomial problems. These problems are such that their steps cannot be expressed in terms of polynomial time and therefore to know the right solutions one has to evaluate many possible alternatives. The property, which can be exploited here, is that all the alternative solutions can be evaluated in parallel and therefore different machines across the Internet can be used simultaneously for evaluation thousands of possible candidate solutions for any such problem. Like in this case the protocol, which is being used for this purpose, is TCP. To understand the • implementation one first needs to have a brief idea of TCP checksum.
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  TCP CHECKSUM:  Thechecksum field is the 16 bit one's complement of the one's complement sum of all 16-bit words in the header and text.  If a segment contains an odd number of header and text octets to be check summed, the last octet is padded on the right with zeros to form a 16-bit word for checksum purposes.  The pad is not transmitted as part of the segment. While computing the checksum, the checksum field itself is replaced with zeros.  information is carried in the Internet Protocol and is transferred across the TCP/Network interface in the arguments or results of calls by the TCP on the IP.
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  Result of Parasiticcomputing : 1. False positive {error-message} 2. False negative {drops message}
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  ADVANTAGES  Server sideparasitic computation determines the fake clients. (i.e. – clients with similar IP address requesting the server)  At schools ,colleges and workplaces admin monitoring is achieved.  Computational capacity of Remote computer is analysed.
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  DISADVANTAGES o Trust Relationshipis breaked. o Denial of service attack without breaking security law. o Remote target computer’s ability to communicate with rest of the internet is eliminated.
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  CONCLUSION  TCP layercan be exploited and also cannot guarantee correctness of result due to False-positive and False-negative.  At present , parasitic computing may be slow technique to solve, but it could be used to load heavy request on server and get the solution for its problem.
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  REFERENCES  http://www.nd.edu/~parasite/  www.nd.edu/~ccrowell/Parasitic%20Computing.pdf http://sit.iitkgp.ernet.in/research/aut05seminar2/report12.pdf