1. www.thetoppersway.com Submitted To: Submitted By: www.thetoppersway.com Seminar On Parasitic Computing

2. Content INTRODUCTION HOW TO TRICK OTHER PEOPLE’S COMPUTERS TO SOLVE A MATH PROBLEM? IMPLEMENTATION USING TCP TCP CHECKSUM COMPUTING WITH TCP ADVANTAGES DISADVANTAGES CONCLUSION REFERENCES

3. INTRODUCTION The net is a fertile place where new ideas/products surface quite often. We have already come across many innovative ideas such as Peer-to-Peer file sharing, distributed computing etc. Parasitic computing is a new in this category.

4. HOW TO TRICK OTHER PEOPLE’S COMPUTERS TO SOLVE A MATH PROBLEM?

5. 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.

6. IMPLEMENTATION USING TCP… till now there 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.

7. TCP CHECKSUM The checksum 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.

8. TCP CHECKSUM… Result of Parasitic computing : 1. False positive {error-message} 2. False negative {drops message}

9. ADVANTAGES Server side parasitic 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.

10. DISADVANTAGES Trust Relationship is breaked. Denial of service attack without breaking security law. Remote target computer’s ability to communicate with rest of the internet is eliminated.

11. CONCLUSION TCP layer can 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.

12. REFERENCES www.google.com www.wikipedia.com www.thetoppersway.com

13. Thanks