PARASITIC COMPUTING Seminar by Rubia Jasmin H.N, Roll No. 54, S7 CSE, MACE
CONTENTS • Introduction • Implementation • Basic of parasite computing • features and advantages • Solving problems with • Challenges and parasite computers disadvantages • 2-SAT problem example • Conclusion • Prototype and architecture
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
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 time- intensive operations.
HOW DOES IT WORKS? Basics of parasite computing
INTERNET COMMUNICATION • While opening a URL, Sender:- Initiator Acceptor Node Node • Open a TCP connection to SYN Time web server SYN+ACK • Issues a HTTP request over ACK Connection Established TCP connection Figure 2: Establishing a TCP connection. • TCP message is carried via IP
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 HTTP > TCP > IP > TCP > HTTP packet
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
CALCULATING CHECKSUM N bits a S 2 S k S 1 16 bit S 1 + Parasite node (sender) S 2 + b S k SUM P 1110101011011011 SUM P 0001010100100100 c Create a new message of length N + 16 S 1 S 2 S k SUM P d SUM T = SUM P + S 1 + S 2 + ... + S k Target (receiver) : message correct 1111111111111111 to HTTP IF SUM T = : message corrupt otherwise drop
SOLVING PROBLEMS USING PARASITE COMPUTING
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.
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
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
2 - SAT PROBLEM Example of a parasite computing problem and discussion on how it is evaluated
2 - SAT PROBLEM a < 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 0 0 0 0 0 0 0 1 1 0 0 1 1 0 1 0 0 1 1 1 0 1 1 0 c M = 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 16 E = 01 00 01 01 00 01 01 01 00 00 01 00 01 01 01 00 S 1 S 2 e d S 1 01 00 01 01 00 01 01 01 0x 1 0x 3 0x 5 0x 7 0x 9 0x 11 0x 13 0x 15 S 2 0x 2 0x 4 0x 6 0x 8 0x 10 0x 12 0x 14 0x 16 00 00 01 00 01 01 01 00 SUM 01 00 10 01 01 10 10 01 10 11 01 10 10 01 01 10 SUM 01 10 01 01 10 01 10 01 (Real checksum) 10 01 10 10 01 10 01 10 T c f Transmitted message 1001101001100110 0100010100010101 0000010001010100 S 1 S 2 T c
2 - SAT PROBLEM - DETAILED • The 2-SAT problem involves 16 • The sum can have 4 outcomes variables with the operations • If the clause has an XOR AND and XOR operator, is true only when the • In order to get a TRUE answer checksum is (01). for P , each clause shown in • If the clause has an AND separate parentheses needs to operator, is true only when the be independently TRUE checksum is (10) • To evaluate, we generate a 32 bit • To turn a package into parasitic message M that contains all 16 message the parasitic node variables, each preceded by a prepares a package, preceded by zero a checksum, and continued by a • TCP groups the bits in two 16 bit 32 bit sequence(S1,S2) segments and add them together.
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
PROTOTYPE OF PARASITIC COMPUTER b Parasite node Target web server a Parasite Logical interfaces HTTP HTTP node {000 ... 00} NIF TCP TCP Segment ALU dropped } {000 ... 10} 1 1 due to invalid . . . 0 Valid 1 checksum IP IP 0 { Physical Network Network interface Correct solution NIF NIF success ALU ALU Invalid solution failure
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.
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
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
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
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
DEALING WITH UN- RELIABILITY • Ask every question multiple times • Ask a question, Q, and its complement !Q
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
REFERENCE • Barabasi et.al. Parasitic Computing, NATURE 412, 30 Aug 2001. • Barabasi et.al. Supplement material for Parasitic Computing: http:// www.nd.edu/~parasite/ • Barger N. Robert & Crowell R. Charles, The ethics of Parasitic Computing, Sept 2003 : www.nd.edu/~ccrowell/Parasitic%20Computing.pdf • Ivars Peterson, Sneaky Calculations, Science News 160, 17 Nov 2001. • www.hindu.com/thehindu/2001/09/13/stories/08130001.htm • http://en.wikipedia.org/wiki/Parasitic_computing
QUESTIONS ?
THANK YOU
SUPPLEMENTARY
TCP MESSAGE FORMAT
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