PARASITIC COMPUTING. Seminar by Rubia Jasmin H.N, Roll No. 54, S7 CSE, MACE

Transcription

1 PARASITIC COMPUTING Seminar by Rubia Jasmin H.N, Roll No. 54, S7 CSE, MACE

2 CONTENTS Introduction Basic of parasite computing Solving problems with parasite computers 2-SAT problem example Implementation features and advantages Challenges and disadvantages Conclusion Prototype and architecture

3 SOME FACTS There is millions of devices connected to internet. These devices can be exploited. There is a way of using the network infrastructure of these devices for different tasks than they are designed for. This will cause slowing down Connection Speed. It is not a cracking, these devices are victims of parasite computing

4 WHAT IS PARASITE COMPUTING? First Reported in journal Nature in 2001 by Barabasi, Freech, feong and Brockman It is a technique of using the resources of one computer by another computer without the knowledge of the former. Standard protocols like TCP,IP and HTTP are exploited. Parasitic computing uses computation power of the computers connected to the internet in solving complex mathematical problems. eg: Traveling salesman problem, NP-SAT problems It is not Distributed computing, which turns home users computers into part of a virtual super computer that can perform timeintensive operations.

5 HOW DOES IT WORKS? Basics of parasite computing

6 INTERNET COMMUNICATION While opening a URL, Sender:- Initiator Node Acceptor Node Open a TCP connection to web server Time SYN SYN+ACK Issues a HTTP request over TCP connection ACK Connection Established TCP message is carried via IP Figure 2: Establishing a TCP connection.

7 INTERNET COMMUNICATION While opening a URL, Actions at receiver :- Receive message through IP Validate checksum at TCP Validated pushed to HTTP Not validated discard the packet HTTP > TCP > IP > TCP > HTTP

8 Parasite computer uses checksum calculation method used in internet communication infrastructure to do computing Normal computer uses Voltage ON-OFF states Parasite Computer user TCP Checksum Valid-Invalid States

9 CALCULATING CHECKSUM N bits a S 1 S 2 S k 16 bit S 1 + Parasite node (sender) b c S 2 S k SUM P SUM P Create a new message of length N SUM P S 1 S 2 S k Target (receiver) d IF SUM T = SUM T = SUM P + S 1 + S S k otherwise : : message correct to HTTP message corrupt drop

10 SOLVING PROBLEMS USING PARASITE COMPUTING

11 TYPE OF PROBLEMS NP-complete - Traveling salesman problem and the satisfiability problem `Satisfiability' (or SAT) problem involves finding a solution to a Boolean equation that satisfies a number of logical clauses. Example : (x1 XOR x2) AND (x2 AND x3) 2-SAT problem - each clause, shown in parentheses, involves two variables, 3 - SAT problem - each clause, shown in parentheses, involves three variables. There is no known algorithm which solves it we follow a brute-force approach, for the 2 n potential solutions.

12 SOLVING A PARASITE COMPUTING PROBLEM Generate large number of candidate solutions. Send each solutions to destination node. Test the candidates for their adequacy. If response is true, the solution is valid, else drop. The result from each were used to build a solution

13 SOLVING PROBLEMS... Problem is split into a large number of simple logic problems. They tag a logic problem onto checksum with TCP message. Web server would process the request. The whole result combine to form the result of the mathematical problem. Target nodes are answering logical questions without knowing of doing so. This does not violate the security of the unknowing server. Potential candidate protocol includetcp, IP, HTTP

14 2 - SAT PROBLEM Example of a parasite computing problem and discussion on how it is evaluated

15 a 2 - SAT PROBLEM P = (x 1 x 2 ) (x 3 x 4 ) (x 5 x 6 ) (x 7 x 8 ) (x 9 x 10 ) (x 11 x 12 ) (x 13 x 14 ) (x 15 x 16 ) < b X Y X Y X Y X+ Y c M = E = 0x 1 0x 3 0x 5 0x 7 0x 9 0x 11 0x 13 0x 15 0x 2 0x 4 0x 6 0x 8 0x 10 0x 12 0x 14 0x d f 01 S 1 0x 1 0x 3 0x 5 0x 7 0x 9 0x 11 0x 15 S 1 0x 2 0x 4 0x 6 0x 8 0x 10 0x 12 0x 14 0x 16 S 2 SUM SUM (Real checksum) Transmitted message T c 0x 13 S S 2 10 S 2 01 T c e

16 2 - SAT PROBLEM - DETAILED The 2-SAT problem involves 16 variables with the operations AND and XOR In order to get a TRUE answer for P, each clause shown in separate parentheses needs to be independently TRUE To evaluate, we generate a 32 bit message M that contains all 16 variables, each preceded by a zero TCP groups the bits in two 16 bit segments and add them together. The sum can have 4 outcomes If the clause has an XOR operator, is true only when the checksum is (01). If the clause has an AND operator, is true only when the checksum is (10) To turn a package into parasitic message the parasitic node prepares a package, preceded by a checksum, and continued by a 32 bit sequence(s1,s2)

17 ALGORITHM S= create TCP segments (x 1, x 2, x 3, x 4.x 15 ) S.checksum = checksum for each x S.data = pad with zeros (x) send S receive answer if answer = true write x as a solution

18 PROTOTYPE OF PARASITIC COMPUTER Parasite node Target web server a { } Parasite node Valid { } { } NIF ALU HTTP TCP IP Logical interfaces HTTP TCP IP Segment dropped due to invalid checksum Network Physical interface Network NIF ALU NIF ALU Correct solution success Invalid solution failure

19 COMPONENTS A single parasite node coordinates the computations occurring remotely in the internet protocols. Each target node consist of Arithmetic and Logic Unit (ALU) Network InterFace (NIF) A single home parasite initiates the computation, sends messages to the, directing them to test and tabulates the result.

20 IMPLEMENTATION There is 2 methods Concurrency: Large number of target nodes, requires a separate a TCP connections to http host Connection reuse: Once TCP connection is opened, same connections is used for multiple calculations In reality this 2 methods can be used together

21 DIFFERENCE WITH CLUSTER COMPUTING Parasite computing does not require the willingness of target machine, Parasite computing does not need special software on any target machine, as in cluster computing Parasite computing is an ethically challenging alternative for cluster computing

22 FEATURES AND ADVANTAGES Theoretically offers the chance to use the vast computational power of the whole internet. Several large computational problems can be solved by engaging various web servers physically located in different parts of the world, each of which unknowingly participated in the experiment. It does not compromise the security of the targeted servers, and access only those parts of the servers that have been made explicitly available for Internet communication

23 CHALLENGES AND DISADVANTAGES For parasites Several computational cycles are taken to process the possible solutions Possibility of false negatives Possibility of false positives 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

24 DEALING WITH UN- RELIABILITY Ask every question multiple times Ask a question, Q, and its complement!q

25 CONCLUSION Enabling all the computers to swap information and services they are needed, could lead to unparalleled emergent behavior, drastically altering the current use of the internet. Parasitic Computing logically moves computation onto the communication infrastructure of internet, blurring the distance between computation and communication The current internet infrastructure permits one computer to instruct other computer to perform computational tasks that are beyond the target s immediate scope

26 REFERENCE Barabasi et.al. Parasitic Computing, NATURE 412, 30 Aug Barabasi et.al. Supplement material for Parasitic Computing: Barger N. Robert & Crowell R. Charles, The ethics of Parasitic Computing, Sept 2003 : Ivars Peterson, Sneaky Calculations, Science News 160, 17 Nov

27 QUESTIONS?

28 THANK YOU

29 SUPPLEMENTARY

30 TCP MESSAGE FORMAT

31 EXAMPLE HTTP - HTML RESPONSE <html> <head> <Title> Notre Dame Computer Science and Engineering </Title> </head> <body bgcolor=white> <center> <img align=middle src= alt="[ U_N_I_V_E_R_S_I_T_Y o_f N_O_T_R_E D_A_M_E ]"> <h1></h1><h2><p> That feature is not implelemented on this server (501): <br> /index.html <H2> If you feel this message is in error, please contact <br> <em><a href="mailto:www@ </em></h2> <H4> Please include the full URL that you are trying to access, <br>or we may not be able to provide you with any assistance.<br><p> <img align=bottom src= <p> <a href= <img align=top src= alt="[back TO ND CSE HOME PAGE]"></a> </center> </body></html> Figure 3: Response from HTTP server