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PARASITIC COMPUTING

PARASITIC COMPUTING. Shashwat Shriparv dwivedishashwat@gmail.com InfinitySoft. OUTLINE. Introduction Internet Communication Proof Of Concept 2-SAT Problem Implementation Using TCP Issues ▪ Problems For Parasites ▪ Problems For Servers How It Differs From Others Future Summary.

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PARASITIC COMPUTING

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  1. PARASITIC COMPUTING Shashwat Shriparv dwivedishashwat@gmail.com InfinitySoft

  2. OUTLINE • Introduction • Internet Communication • Proof Of Concept • 2-SAT Problem • Implementation Using TCP • Issues ▪ Problems For Parasites ▪ Problems For Servers • How It Differs From Others • Future • Summary

  3. Introduction • First Reported in journal ‘Nature’ in 2001 by Barabasi, Freech, Feong and Brockman • A form of distributed computing • Used for solving complex computational problems • Exploits standard set of communication protocols on internet. • Potential candidate protocols include TCP,HTTP, or encryption/decryption with secure socket layer

  4. Internet Communication When a user selects a URL Actions at center ▪Open a TCP connection to web server ▪ Issues a HTTP request over TCP connection ▪ TCP message is carried via IP

  5. Establishing a TCP connection.

  6. Internet Communication • Actions at receiver ▪Receive message through IP ▪Validate checksum at TCP ◦Validated pushed to HTTP ◦Not validated discard the packet

  7. Internet Communication

  8. Proof Of Concept • Solved the SAT problem • Usually solved by testing several candidate solutions • Each candidate solution can be examined in parallel

  9. Implementation • Computations takes place at many layers in internet • Several internet protocols could be exploited to perform parasitic computation • Implementation made using TCP or higher levels

  10. Implementation Using TCP • TCP checksums Provide enough logic to compute any boolean function • HTTP service Protocol always send a response to any message received

  11. TCP Checksum • Sender breaks message into 16 bit words • These words are added together • The result is inverted and send with message • Receiver breaks message into 16 bit words • All words are added together • If the result is all ones, the message is valid • Otherwise, the message is dropped

  12. TCP/IP segment used for parasitic computing

  13. 2-SAT Problem

  14. Solving 2-SAT Problem • Send a specially created TCP packet containing a possible solution • If the possible solution is correct, the HTTP server returns an error message • If the solution is wrong, then packet is dropped at TCP layer

  15. Creating Parasitic Messages • Variables values of a possible solution are distributed so they will align when split in 16 bit words • TCP checksum sent is a representation of the expected answer • “Parasitic” checksum and the variable string are sent to remote machine for verification

  16. Algorithm S = create TCP segment S.checksum = checksum foreach x S.data = pad with zeroes (x ) send S receive answer if answer = true write x is a solution

  17. Prototype Of Parasitic Computing

  18. 3-SAT Problem • NP complete • Can be solved similar to 2-SAT because the maximum sum of three variables is 1+1+1=11,which can be represented by two bits without overflow • The algorithm does not change, only the way to create packet is changed

  19. Problems For Parasites • Several computational cycles are taken to process the possible solutions • Possibility of false negatives • Possibility of false positives

  20. Problems For Servers • Delays due to processing the parasitic messages could cause a denial of service • Almost impossible to prevent someone from running a parasitic job on your server ▪ Removing or changing the exploited functions would cause the server to be unable to communicate on the internet

  21. How It Differs From Others • Cluster computing ▪ In cluster computing, many computers pool in their resources willingly ▪ Parasitic computing does not require the willingness of any target machine • It is not cracking

  22. Future • Computation-to-communication ratio must increase • Exploiting HTTP or encryption/decryption could execute in an efficient manner. • Enabling all computers to swap information and services they are needed could lead to unparalleled emergent behavior, drastically altering the current use of the Internet.

  23. Summary • parasitic computing moves computation onto what is logically the communication infrastructure of the Internet, blurring the distinction between computing and communication.

  24. References • Barabasi et.al., Parasitic Computing, NATURE 412, 30 Aug 2001. • Barabasi et.al. Supplement material for Parasitic Computing : http://www.nd.edu/~parasite/ • www.hindu.com/thehindu/2001/09/13/stories/08130001.htm

  25. Thank You Shashwat Shriparv dwivedishashwat@gmail.com InfinitySoft

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