NAME : RUCHIKA KUMARIUSN : 1MS06IS062BRANCH : I.S.E

PARASITIC COMPUTING

PARASITIC COMPUTINGOUTLINE Introduction Experimental evidence Theory Proof of concepts 2-SAT problem How it differs from others Advantages Disadvantages conclusion References

PARASITIC COMPUTING

INTRODUCTION First reported in Journal “Nature” in 2001 by Barabasi, Freeh, Jeong and Brockman A Successor to distributed computing

Used for solving complex computational problems

Exploits standard set of communication protocol on internet

What Is Parasitic

computing?

PARASITIC COMPUTING

DEFINITION The term “parasitic computing” refers

to the technique of using the resources of one computer by another computer without the knowledge of the former.

It uses the computation power of the computers connected to the internet in solving complex mathematical problems.

Ex: Travelling Salesman, Satisfiability problem

PARASITIC COMPUTING

EXRERIMENTAL EVIDENCE ?

Internet communication.

PARASITIC COMPUTING When user selects a URL Actions at sender Open a TCP connection to a web server Issue a HTTP request over TCP connection TCP message is carried via IP Actions at receiver Receive message through IP Validate checksum at TCP Validated pushed to HTTP Not validated discard the packet

PARASITIC COMPUTING

Theory To Solve Problem Generate a large number of candidate

solutions

Send the solutions to destination node

Test the candidate for their adequacy

If result is true, the solution is valid else drop

The result from each is combined to get solution

Candidate Solution Can be tested in parallel ,an effective computer architecture for these problems is one that supports simultaneous evolution of many tests.

An example of such a machine is shown beside.

HOWTO TRICK OTHER COMPUTERS

------ ----- ------- ---- ------ ----- ------- ------- ----- -------- ------------- -------- ------- -------- ----

Parasite Node

-------

NIF

ALU

NIF

ALU

NIF

ALU

010 -11

000--10

000--00

valid . . . .

.

PARASITIC COMPUTING

A single Parasite node coordinate the computation

occurring remotely in the internet protocol. each of target node consist of

Arithmetic and Logic Unit(ALU) Network Interface(NIF)

Single home parasite initiate the computation, directing them to test and tabulate the result.

PARASITIC COMPUTING

HHTTP

T TCP

Network

IP

HHTTP

T TCP

Network

IP

Parasitic node Target web server

Physical Interface

Correct solution success

Invalid solution failure

Segment dropped Due to invalid Checksum

Log

ical

Inte

rface

PARASITIC COMPUTING

CHECKSUM COMPUTATION The checksum is a simple function

performed by all web servers(in TCP), which allows a recipient to check if the message is corrupted during transmission.

Message is constructed in such a way

that TCP checksum fails for all messages containing an invalid solution

a. Parasitic node

breaks N bit

message into 16-

bit words as

S1….Sk

b. K words are

added together

and one’s-

complement is

done to get SUM

c. Checksum and

its complement

d. Again receiver

will break the

received message

and add

PARASITIC COMPUTING

S1 S2 Sk

S2

S1

Sk

SUM 1110101011011011SUM 0001010100100100

16 bit

N bits

S1 S2 SkSUM

Create a new message of length N+ 16

d SUM T= SUM+S1+S2+-------+ Sk

if SUMT=1111111111111111 message correct -> to HTTPOtherwise message corrupt -> drop

a

b

c

+

+

Para

site

nod

eTarg

et(

receiv

er)

PARASITIC COMPUTING

PROOF OF CONCEPT

N-P complete problem problems for which no polynomial-time algorithm is known SAT problem SAT problem involves finding a solution to a

Boolean equation that satisfies a number of logical clauses

PARASITIC COMPUTING

2-SAT PROBLEM

P=(x1 x2)˄(x3 x4)˄(x5 x6)˄(x7 x8)˄(x9 ˄x10)˄(x11 x12)˄(x13˄x14 )˄(x15 x16)

X Y X Y

X ˄Y X+Y

0 0 0 0 00

0 1 1 0 01

1 0 1 0 01

1 1 0 1 10

PARASITIC COMPUTING

0x1 0x3 0x5 0x7 0x9 0x11 0x130x15

01 00 01 01 00 01 01 01

0x2 0x4 0x6 0x8 0x10 0x12 0x140x16

00 00 01 00 01 01 01 00

M=E=

0x1 0x3 0x5 0x7 0x9 0x11 0x13

0x15

0x2 0x4 0x6 0x8 0x10 0x12 0x14

0x16

˄ ˄ ˄ 01 10 01 01 10 01 10 01

S1 01 00 01 01 00 01 01 01S2 00 00 01 00 01 01 01 00

SUM 01 00 10 01 01 10 10 01

SUM (Real Checksum)

10 11 01 10 10 01 01 10

10 01 10 10 01 10 01 10

1001101001100110

0100010100010101

0000010001010100

Tc

Transmitted Message

Tc S1

S2

PARASITIC COMPUTING

HOW IT DIFFERS FROM OTHERS?

PARASITIC COMPUTING

Cluster computing

PARASITIC COMPUTING

It is not hacking

PARASITIC COMPUTINGADVANTAGES Theoretically gives chance to use vast

computational power of the internet

Several large problem can be solved by engaging various web server physically located at different part of world

It does not comprise the security of target node it access only the part to server that have been made explicitly available for internet communication

PARASITIC COMPUTING

DISADVANTAGES Internet wide parasitic computing is only

a theoretical consideration Communication to computation ratio

Delayed Services

PARASITIC COMPUTING

CONCLUSION Blurring the distinction between

computation and communication and drastically altering the current use of internet

Implementation offered above represents only proof of concepts it merely serves to implement idea behind parasitic computing.

PARASITIC COMPUTING

Cont..

TCP checksum provides computation at the cost of hundreds of machine cycles

To make model viable the computation –to-

communication ration must be large

PARASITIC COMPUTING

REFERENCES

http://en.wikipedia.org/wiki/Parasitic_computing

http://www.nd.edu/~parasite/ http://en.wikipedia.org/wiki/2-satisfiability http://www.hindu.com/thehindu/

2001/09/13/stories/08130001.htm

Thank YOU