slides for parasite computing
TRANSCRIPT
PARASITIC COMPUTINGSeminar by
Rubia Jasmin H.N, Roll No. 54, S7 CSE, MACE
CONTENTS• Introduction
• Basic of parasite computing
• Solving problems with parasite computers
• 2-SAT problem example
• Prototype and architecture
• Implementation
• features and advantages
• Challenges and disadvantages
• Conclusion
• 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
SOME FACTS
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
Time
AcceptorNode
InitiatorNode
SYN
SYN+ACK
ACKConnectionEstablished
Figure 2: Establishing a TCP connection.
values of and and the checksum ( ) are shown in blue.TCP is a connection-oriented protocol—meaning that a connection must first be established before data
is sent. A connection is established with three messages, see Figure 2. First, the initiator sends a SYN(the TCP SYN flag is set) to a remote node. If the remote node is willing to accept a new connection, itresponds with a SYN/ACK (both the SYN and ACK flags are set) message. Finally, the initiator sends anACK message [1, 2]. In these messages nodes exchange initial sequence numbers. The test TCP segments,constructed as above, are sent following the establishment of a connection.
Because we are connecting to an HTTP server, the response received depends on the configuration ofthe server. However, all we care about is whether there is a response or not. The correct solution results ina valid TCP segment, but it is not a valid HTTP request. Therefore, the response will be something like thatin Figure 3.
3 Algorithm
An 8-variable 2-SAT problem problem is shown below.
(1)
The solution vector, , has 8 elements that can range over 0 and 1. Thus there are possible solutions for. The only correct solution to (1) is: . Our algorithm tests each solution using aspecially constructed TCP/IP packet, as shown in Figure 1.
The high-level algorithm is:
S = create TCP segmentS.checksum = checksumforeachS.data = pad with zeroes( )send Sreceive answerif answer = true write is a solution
First, we create a TCP segment that contains all the standard header information required by the protocol.Next the checksum field is set. The solution determines the checksum, as discussed in Figure 3 in the text;
3
INTERNET COMMUNICATION
• While opening a URL, Sender:-
• Open a TCP connection to web server
• Issues a HTTP request over 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 packet HTTP > TCP > IP > TCP > HTTP
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
!"##"$% #& '(#)$"
*+, !"#$%& ' ()* +,- ' ./ "$0$1# -//, ' 22234567893:;<
:=9:>?7<3 #=9 :;4?687:6@;4 ;A 6=9 <9??5B9 CD@B3 .E 94?789? 6=56 6=9#FG :=9:>?7< A5@H? A;8 5HH <9??5B9? :;465@4@4B 54 @4I5H@J ?;H76@;46; 6=9 K;?9J 1"# K8;LH9<3 #=7?M 5 <9??5B9 6=56 K5??9? 6=9 #FG:=9:>?7< :;465@4? 5 :;889:6 ?;H76@;43 #=9 658B96 ?98I98 2@HH 89?K;4J6; 95:= <9??5B9 @6 89:9@I9? C9I94 @A @6 J;9? 4;6 74J98?654J 6=989N79?6E3 "? 5 89?7H6M 5HH <9??5B9? :;465@4@4B @4I5H@J ?;H76@;4? 589J8;KK9J @4 6=9 #FG H5O983 )4HO 5 <9??5B9 2=@:= 94:;J9? 5 I5H@J?;H76@;4 P895:=9?Q 6=9 658B96 ?98I98M 2=@:= ?94J? 5 89?K;4?9 6; 6=9P89N79?6Q @6 89:9@I9J3R9 =5I9 @<KH9<9469J 6=9 5L;I9 ?:=9<9 7?@4B 5? 5 K585?@6@: 4;J9
54 ;8J@458O J9?>6;K <5:=@49 2@6= #FGSTG 4962;8>@4B3 #=9 658UB969J :;<K7698? 589 I58@;7? 29L ?98I98? K=O?@:5HHO H;:569J @4 !;86="<98@:5M &78;K9M 54J "?@5M 95:= ;A 2=@:= 742@66@4BHO K586@:@K569J@4 6=9 9VK98@<9463 "? 9VKH5@49J @4 D@B3 ,M ;78 K585?@69 4;J9J@?68@L769J -!<9??5B9? L962994 6=9 658B96?3 W9:57?9 ;4HO <9??5B9?:;465@4@4B I5H@J ?;H76@;4? 6; 6=9 1"# K8;LH9< K5?? 6=8;7B= #FGM6=9 658B96 29L ?98I98 89:9@I9J ;4HO I5H@J ?;H76@;4?3 #=@? @? @4698UK8969J 5? 54 X##G 89N79?6M L76 @6 @? ;A :;78?9 <954@4BH9?? @4 6=@?:;469V63 "? 89N7@89J LOX##GM 6=9 658B96 29L ?98I98 ?94J? 5 89?K;4?96; 6=9 K585?@6@: 4;J9M @4J@:56@4B 6=56 @6 J@J 4;6 74J98?654J 6=989N79?63 #=9 K585?@69 4;J9 @4698K896? 6=@? 89?K;4?9 5? 5669?6@4B 6; 6=9I5H@J@6O ;A 6=9 ?;H76@;43 "? 9VK9:69J 54J LO J9?@B4M @4:;889:6
?;H76@;4? J; 4;6 B9498569 89?K;4?9? A;8 6=9 29L ?98I983 " 6OK@:5H<9??5B9 ?946 LO 6=9 K585?@69M 54J 5 6OK@:5H 89?K;4?9 A8;< 5 658B9629L ?98I98 589 @4:H7J9J @4 6=9 17KKH9<94658O T4A;8<56@;43)78 69:=4@N79 J;9? 4;6 89:9@I9 5 K;?@6@I9 5:>4;2H9JB9<946 6=56
5 ?;H76@;4 @? @4I5H@J L9:57?9 54 @4I5H@J ?;H76@;4 @? J8;KK9J LO #FG3F;4?9N7946HOM 6=989 @? 5 K;??@L@H@6O ;A A5H?9 49B56@I9?Y :5?9? @4 2=@:=5 :;889:6 ?;H76@;4 @? 4;6 8967849JM 2=@:= :54 ;::78 A;8 62; 895?;4?3D@8?6M 6=9 TG K5:>96 :;7HJ L9 J8;KK9JM 2=@:= <@B=6 L9 J79 6; J565:;887K6@;4 ;8 :;4B9?6@;43 !;8<5HHO #FG K8;I@J9? 5 89H@5L@H@6O<9:=54@?< 5B5@4?6 ?7:= 9I946?ZM L76 ;78 :788946 @<KH9<94656@;4:544;6 65>9 5JI5465B9 ;A 6=@?3 19:;4JM L9:57?9 6=@? 69:=4@N799VKH;@6? 6=9 #FG :=9:>?7<M @6 :@8:7<I946? 6=9 A74:6@;4 6=9 :=9:>U?7< K8;I@J9?3 #=9 #FG :=9:>?7< :56:=9? 988;8? 6=56 589 4;6 :57B=6@4 6=9 :=9:>? K8;I@J9J LO 6=9 6854?K;86 H5O98M ?7:= 5? 988;8? @4
Create a new message of length N + 16c
b
0001010100100100
SUMP
SUMP
d
a
16 bit
N bits
Par
asite
nod
e (s
ende
r)
1110101011011011
+
+
Targ
et (r
ecei
ver)
: message correct
IF SUMT =
: message corrupt
drop
to HTTP
S2S1 Sk
1111111111111111
otherwise
SUMT = SUMP + S1 + S2 + ... + Sk
S1
S2
Sk
SUMP S2S1 Sk
!"#$%& ' !"# $%&$'()*+ (, !%& $%&$'()* -( . (-*/0& 1)2$3-42 /&5145*&6 78 .00 9&7
(&5:&5( ;-2 !"#<, 9%-$% .0049( . 5&$-/-&23 34 $%&$' -1 3%& 5&$&-:&6 *&((.=& %.( 7&&2
$455)/3&6 6)5-2= 35.2(*-((-42+ !%& (&26&5 ;/.5.(-3-$ 246&< 75&.'( 3%& *&((.=&
$42(-(3-2= 41 ! 7-3( -234 >?@7-3 9456(, (%492 .( ">, "A,!, "#+ ), !%& # 9456( .5& .66&6
34=&3%&5 )(-2= 7-2.58 42&B(@$4*/0&*&23 .5-3%*&3-$, /54:-6-2= 3%& ()* 6&243&6 .( CDE$ +
F&G3, 3%& (&26&5 /&5145*( . 7-3@9-(& $4*/0&*&23 42 3%& $%&$'()*, (4 3%.3 &:&58 7-3 -(
H-//&6I . J 7&$4*&( . > .26 . > 7&$4*&( . J, 473.-2-2= CDE$ + K2 &G.*/0& 41 .
$%&$'()* .26 -3( $4*/0&*&23 .5& (%492 -2 3%& L=)5&+ *, !%& (&26&5 -2$45/45.3&( 3%&
$4*/0&*&23 41 3%& $%&$'()* -234 3%& %&.6&5 41 3%& *&((.=&+ +, !%& 5&$&-:-2= $4*/)3&5
;3.5=&3< .=.-2 75&.'( 3%& 5&$&-:&6 *&((.=& -234 >?@7-3 (&=*&23( .26 .66( 3%&* 34=&3%&5+
!%& :.0)& 41 3%& $%&$'()* CDE! $.0$)0.3&6 78 3%& 3.5=&3 -( CDE$ ! CDE$ , 3%& L5(3 3&5*
$4*-2= 154* 3%& %&.6&5 .26 3%& (&$426 3&5* 7&-2= 3%& $4235-7)3-42 154*
" > ! " A !!! "# + K( CDE$ .26 CDE$ .5& $4*/0&*&23.58, 3%& $%&$'()* 473.-2&6
78 3%& 5&$&-:&5 %.( 34 7& >>>>>>>>>>>>>>>>+ M1 .28 7-3 .042= 3%& *&((.=& %.( 7&&2
$455)/3&6 6)5-2= 35.2(*-((-42, 3%& $%&$'()* 473.-2&6 78 3%& 3.5=&3 9-00 7& 6-11&5&23 154*
.00 42&(, -2 9%-$% $.(& 3%& 3.5=&3 654/( 3%& *&((.=&+ K 242@$455)/3&6 *&((.=& -( /.((&6
34 3%& N!!# /5434$40, 9%-$% 9-00 .33&*/3 34 -23&5/5&3 -3( $423&23+
00 00 01 0100 01 0001
01
00010001
10010110 01 0110
01 00010100
01
11 10 10 01(Real checksum)
01 100110010001 0110 011010
10011001
Transmitted message000001000101010001000101000101011001101001100110
10Tcf
d
SUM
100110
SUM
S2
01 0101
S1
M =c
e
b
E =
a
010x120x1 0x110x9 0x100x80x2 0x160x140x3
01000100 01 000001 01010x70x5 0x150x13
0
1
1 1
0
1
1
0
0
1
0
0 0
YXYX X
0x60x4
YY
0 0
1
0
0 0 1
X +
1 0
0 1
P = (x1 x2) (x3 x4) (x5 x6) (x7 x8) (x9 x10) (x11 x12) (x13 x14) (x15 x16)
0x1 0x110x90x3 0x70x5 0x150x130x120x100x80x2 0x160x140x60x4
S1S2
S2S1Tc
!"#$%& , O&$-6-2= (.3-(L.7-0-38 )(-2= $%&$'()*+ !%& A@CK! /5470&* (%492 -2 ( -2:40:&(
>? :.5-.70&( [% >! % A!!! % >?\ .26 3%& 4/&5.345( KFO ;!< .26 PQR ;!<+ ), !%& 04=-$.0 3.70&41 PQR, KFO .26 3%& 7-2.58 ()* ;!<+ M2 456&5 34 =&3 . !RDS .2(9&5 145 $, &.$% $0.)(&
(%492 -2 (&/.5.3& /.5&23%&(&( -2 ( 2&&6( 34 7& -26&/&26&2308 !RDS+ *, !4 &:.0).3& 3%&
:.0)& 41 $ 9& =&2&5.3& . TA@7-3 *&((.=& & 3%.3 $423.-2( .00 >? :.5-.70&(, &.$% /5&$&6&6
78 . U&54+ K( .2 -00)(35.3-42, 9& (%49 . /4((-70& (40)3-42 '+ !"# =54)/( 3%& 7-3( 41 3%&
5&$&-:&6 *&((.=& -2 394 >?@7-3 (&=*&23 .26 .66( 3%&* 34=&3%&5 ;V-=+ A.<+ K( (%492 -2 +,3%-( 9-00 5&()03 -2 .66-2= &.$% ;% ( ! % (!>< /.-5 34=&3%&5 9%&5& ( -( 466+ !%& ()* $.2 %.:& 14)5
4)3$4*&(+ "4*/.5-2= 3%& ()*9-3% 3%& ;!< $40)*2 -2 3%& 3.70& -2 ), 9& 243-$& 3%.3 . !RDS.2(9&5 145 3%& PQR $0.)(& ;% ( ! % (!>< $4-2$-6&( 9-3% 3%& ;J>< 5&()03 41 3%& ;% ( ! % (!>< ()*+
C-*-0.508, -1 3%& $0.)(& %.( .2 KFO 4/&5.345, ;% ( ! % (!>< -( 35)& 4208 9%&2 3%& $%&$'()* -(
;>J<+ !%-( -*/0-&( 3%.3 145 . (&3 41 :.5-.70&( [% >! % A!!! % >?\ 3%.3 (.3-(L&( $ 3%& $%&$'()*
9-00 7& 6&3&5*-2&6 78 3%& $455&(/426-2= 4/&5.345( 4208 ;3%.3 -(, . ! (%4)06 =-:& ;J>< 145
3%& ()* $%&$', .26 145! 3%& ()* -( ;>J<<+ V45 -00)(35.3-42, -2 +9& (%49 3%& 145*.0 0-2&)/ 41
3%& :.5-.70&(, 9%-0& -2 & 9& (%49 .2 &G/0-$-3 &G.*/0&+ !%& $455&$3 $4*/0&*&23&6
$%&$'()* 145 ' (%4)06 7& CDE " >J>>J>>J>JJ>>J+ M2 $4235.(3, 3%& /.5.(-3-$ $4*/)3&5
/0.$&( -2 3%& %&.6&5 3%& 35.2(*-33&6 $%&$'()* ) $ " >JJ>>J>JJ>>JJ>>J, 9%-$% -(
)2-W)&08 6&3&5*-2&6 78 3%& 4/&5.345( -2 $, .( (%492 -2 ++ !4 3)52 3%& /.$'.=& -234 .
/.5.(-3-$ *&((.=& 3%& /.5.(-3-$ 246& /5&/.5&( . /.$'.=&, (%492 -2 -, /5&$&6&6 78 .
$%&$'()* )$, .26 $423-2)&6 78 . TA@7-3 (&W)&2$& ;">, "A<, 9%-$% 5&/5&(&23 42& 41 3%& A>?
/43&23-.0 (40)3-42(+ M1 "> .26 "A 64 243 5&/5&(&23 3%& $455&$3 (40)3-42, 3%&2 3%& $%&$'()*
&:.0).3&6 78 3%& 3.5=&3 !"# 9-00 243 =-:& 3%& $455&$3 ()* ;>>>!>><+ !%& !"# 0.8&5 .3 3%&
3.5=&3 $42$0)6&( 3%.3 3%& *&((.=& %.( 7&&2 $455)/3&6, .26 654/( -3+ N49&:&5, -1 "> .26 "A$423.-2 3%& :.0-6 (40)3-42, 3%& *&((.=& -( (&23 34 N!!#+ !%& 9&7 (&5:&5 -23&5/5&3( 3%&
(40)3-42 .( .2 N!!# 5&W)&(3X %49&:&5, 7&$.)(& -3 -( 243 . :.0-6 N!!# 5&W)&(3, 3%& 9&7
(&5:&5 5&(/426( 9-3% . *&((.=& (.8-2= (4*&3%-2= 0-'& Y/.=& 243 14)26B ;5&6 .5549 -2 V-=+
>.<+ !%)(, &:&58 *&((.=& 34 9%-$% 3%& /.5.(-3& 246& 5&$&-:&( . 5&(/42(& -( . (40)3-42 34
3%& /4(&6 CK! /5470&* ;(&& V-=+ A6<+
© 2001 Macmillan Magazines Ltd
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 2n 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 PROBLEMExample of a parasite computing problem and discussion on
how it is evaluated
!"##"$% #& '(#)$"
*+, !"#$%& ' ()* +,- ' ./ "$0$1# -//, ' 22234567893:;<
:=9:>?7<3 #=9 :;4?687:6@;4 ;A 6=9 <9??5B9 CD@B3 .E 94?789? 6=56 6=9#FG :=9:>?7< A5@H? A;8 5HH <9??5B9? :;465@4@4B 54 @4I5H@J ?;H76@;46; 6=9 K;?9J 1"# K8;LH9<3 #=7?M 5 <9??5B9 6=56 K5??9? 6=9 #FG:=9:>?7< :;465@4? 5 :;889:6 ?;H76@;43 #=9 658B96 ?98I98 2@HH 89?K;4J6; 95:= <9??5B9 @6 89:9@I9? C9I94 @A @6 J;9? 4;6 74J98?654J 6=989N79?6E3 "? 5 89?7H6M 5HH <9??5B9? :;465@4@4B @4I5H@J ?;H76@;4? 589J8;KK9J @4 6=9 #FG H5O983 )4HO 5 <9??5B9 2=@:= 94:;J9? 5 I5H@J?;H76@;4 P895:=9?Q 6=9 658B96 ?98I98M 2=@:= ?94J? 5 89?K;4?9 6; 6=9P89N79?6Q @6 89:9@I9J3R9 =5I9 @<KH9<9469J 6=9 5L;I9 ?:=9<9 7?@4B 5? 5 K585?@6@: 4;J9
54 ;8J@458O J9?>6;K <5:=@49 2@6= #FGSTG 4962;8>@4B3 #=9 658UB969J :;<K7698? 589 I58@;7? 29L ?98I98? K=O?@:5HHO H;:569J @4 !;86="<98@:5M &78;K9M 54J "?@5M 95:= ;A 2=@:= 742@66@4BHO K586@:@K569J@4 6=9 9VK98@<9463 "? 9VKH5@49J @4 D@B3 ,M ;78 K585?@69 4;J9J@?68@L769J -!<9??5B9? L962994 6=9 658B96?3 W9:57?9 ;4HO <9??5B9?:;465@4@4B I5H@J ?;H76@;4? 6; 6=9 1"# K8;LH9< K5?? 6=8;7B= #FGM6=9 658B96 29L ?98I98 89:9@I9J ;4HO I5H@J ?;H76@;4?3 #=@? @? @4698UK8969J 5? 54 X##G 89N79?6M L76 @6 @? ;A :;78?9 <954@4BH9?? @4 6=@?:;469V63 "? 89N7@89J LOX##GM 6=9 658B96 29L ?98I98 ?94J? 5 89?K;4?96; 6=9 K585?@6@: 4;J9M @4J@:56@4B 6=56 @6 J@J 4;6 74J98?654J 6=989N79?63 #=9 K585?@69 4;J9 @4698K896? 6=@? 89?K;4?9 5? 5669?6@4B 6; 6=9I5H@J@6O ;A 6=9 ?;H76@;43 "? 9VK9:69J 54J LO J9?@B4M @4:;889:6
?;H76@;4? J; 4;6 B9498569 89?K;4?9? A;8 6=9 29L ?98I983 " 6OK@:5H<9??5B9 ?946 LO 6=9 K585?@69M 54J 5 6OK@:5H 89?K;4?9 A8;< 5 658B9629L ?98I98 589 @4:H7J9J @4 6=9 17KKH9<94658O T4A;8<56@;43)78 69:=4@N79 J;9? 4;6 89:9@I9 5 K;?@6@I9 5:>4;2H9JB9<946 6=56
5 ?;H76@;4 @? @4I5H@J L9:57?9 54 @4I5H@J ?;H76@;4 @? J8;KK9J LO #FG3F;4?9N7946HOM 6=989 @? 5 K;??@L@H@6O ;A A5H?9 49B56@I9?Y :5?9? @4 2=@:=5 :;889:6 ?;H76@;4 @? 4;6 8967849JM 2=@:= :54 ;::78 A;8 62; 895?;4?3D@8?6M 6=9 TG K5:>96 :;7HJ L9 J8;KK9JM 2=@:= <@B=6 L9 J79 6; J565:;887K6@;4 ;8 :;4B9?6@;43 !;8<5HHO #FG K8;I@J9? 5 89H@5L@H@6O<9:=54@?< 5B5@4?6 ?7:= 9I946?ZM L76 ;78 :788946 @<KH9<94656@;4:544;6 65>9 5JI5465B9 ;A 6=@?3 19:;4JM L9:57?9 6=@? 69:=4@N799VKH;@6? 6=9 #FG :=9:>?7<M @6 :@8:7<I946? 6=9 A74:6@;4 6=9 :=9:>U?7< K8;I@J9?3 #=9 #FG :=9:>?7< :56:=9? 988;8? 6=56 589 4;6 :57B=6@4 6=9 :=9:>? K8;I@J9J LO 6=9 6854?K;86 H5O98M ?7:= 5? 988;8? @4
Create a new message of length N + 16c
b
0001010100100100
SUMP
SUMP
d
a
16 bit
N bits
Par
asite
nod
e (s
ende
r)
1110101011011011
+
+
Targ
et (r
ecei
ver)
: message correct
IF SUMT =
: message corrupt
drop
to HTTP
S2S1 Sk
1111111111111111
otherwise
SUMT = SUMP + S1 + S2 + ... + Sk
S1
S2
Sk
SUMP S2S1 Sk
!"#$%& ' !"# $%&$'()*+ (, !%& $%&$'()* -( . (-*/0& 1)2$3-42 /&5145*&6 78 .00 9&7
(&5:&5( ;-2 !"#<, 9%-$% .0049( . 5&$-/-&23 34 $%&$' -1 3%& 5&$&-:&6 *&((.=& %.( 7&&2
$455)/3&6 6)5-2= 35.2(*-((-42+ !%& (&26&5 ;/.5.(-3-$ 246&< 75&.'( 3%& *&((.=&
$42(-(3-2= 41 ! 7-3( -234 >?@7-3 9456(, (%492 .( ">, "A,!, "#+ ), !%& # 9456( .5& .66&6
34=&3%&5 )(-2= 7-2.58 42&B(@$4*/0&*&23 .5-3%*&3-$, /54:-6-2= 3%& ()* 6&243&6 .( CDE$ +
F&G3, 3%& (&26&5 /&5145*( . 7-3@9-(& $4*/0&*&23 42 3%& $%&$'()*, (4 3%.3 &:&58 7-3 -(
H-//&6I . J 7&$4*&( . > .26 . > 7&$4*&( . J, 473.-2-2= CDE$ + K2 &G.*/0& 41 .
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" > ! " A !!! "# + K( CDE$ .26 CDE$ .5& $4*/0&*&23.58, 3%& $%&$'()* 473.-2&6
78 3%& 5&$&-:&5 %.( 34 7& >>>>>>>>>>>>>>>>+ M1 .28 7-3 .042= 3%& *&((.=& %.( 7&&2
$455)/3&6 6)5-2= 35.2(*-((-42, 3%& $%&$'()* 473.-2&6 78 3%& 3.5=&3 9-00 7& 6-11&5&23 154*
.00 42&(, -2 9%-$% $.(& 3%& 3.5=&3 654/( 3%& *&((.=&+ K 242@$455)/3&6 *&((.=& -( /.((&6
34 3%& N!!# /5434$40, 9%-$% 9-00 .33&*/3 34 -23&5/5&3 -3( $423&23+
00 00 01 0100 01 0001
01
00010001
10010110 01 0110
01 00010100
01
11 10 10 01(Real checksum)
01 100110010001 0110 011010
10011001
Transmitted message000001000101010001000101000101011001101001100110
10Tcf
d
SUM
100110
SUM
S2
01 0101
S1
M =c
e
b
E =
a
010x120x1 0x110x9 0x100x80x2 0x160x140x3
01000100 01 000001 01010x70x5 0x150x13
0
1
1 1
0
1
1
0
0
1
0
0 0
YXYX X
0x60x4
YY
0 0
1
0
0 0 1
X +
1 0
0 1
P = (x1 x2) (x3 x4) (x5 x6) (x7 x8) (x9 x10) (x11 x12) (x13 x14) (x15 x16)
0x1 0x110x90x3 0x70x5 0x150x130x120x100x80x2 0x160x140x60x4
S1S2
S2S1Tc
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3.5=&3 $42$0)6&( 3%.3 3%& *&((.=& %.( 7&&2 $455)/3&6, .26 654/( -3+ N49&:&5, -1 "> .26 "A$423.-2 3%& :.0-6 (40)3-42, 3%& *&((.=& -( (&23 34 N!!#+ !%& 9&7 (&5:&5 -23&5/5&3( 3%&
(40)3-42 .( .2 N!!# 5&W)&(3X %49&:&5, 7&$.)(& -3 -( 243 . :.0-6 N!!# 5&W)&(3, 3%& 9&7
(&5:&5 5&(/426( 9-3% . *&((.=& (.8-2= (4*&3%-2= 0-'& Y/.=& 243 14)26B ;5&6 .5549 -2 V-=+
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3%& /4(&6 CK! /5470&* ;(&& V-=+ A6<+
© 2001 Macmillan Magazines Ltd
2 - SAT PROBLEM
<
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)
ALGORITHM
S= create TCP segments (x1, x2, x3, x4……….x15)S.checksum = checksumfor each x S.data = pad with zeros (x) send S receive answer if answer = true write x as a solution
PROTOTYPE OF PARASITIC COMPUTER
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#; D<EC9<946 5 E585?D6D: :;<E7698 7?D4S 6@9 :@9:O?7< H74:6D;429 499> 6; >9?DS4 5 ?E9:D5C <9??5S9 6@56 :;98:9? 5 658S96 ?98I98 D46;E98H;8<D4S 6@9 >9?D89> :;<E7656D;43 "? 5 69?6 E8;BC9< 29 :@;;?96; ?;CI9 6@9 29CC O4;24 L?56D?Q5BDCD6RM V;8 1"#Y E8;BC9<K 2@D:@ D? 5:;<<;4 69?6 H;8 <54R 747?75C :;<E7656D;4 <96@;>?+K`3 #@9 1"#E8;BC9< D4I;CI9? Q4>D4S 5 ?;C76D;4 6; 5 \;;C954 9[756D;4 6@56?56D?Q9? 5 47<B98 ;H C;SD:5C :C57?9?3 ];8 9G5<EC9K V!, a)% !-Y "!_V!!- "!_ !.Y D4 E8D4:DEC9 @5? -. E;6946D5C ?;C76D;4?K B76 D6 D??56D?Q9> ;4CR BR 6@9 ?;C76D;4 !, ! ,K !- ! /K 54> !. ! ,3 #@D? D?:5CC9> 5 -A1"# E8;BC9< B9:57?9 95:@ :C57?9K ?@;24 D4 E58946@9?9?KD4I;CI9? 62; I58D5BC9?3 #@9 <;89 >DHQ:7C6 .A1"# E8;BC9< D?O4;24 6; B9 !P :;<EC969K 2@D:@ D4 E85:6D:9 <954? 6@56 6@989 D?4; O4;24 E;CR4;<D5CA6D<9 5CS;8D6@< 2@D:@ ?;CI9? D63 F4>99>K6@9 B9?6 O4;24 5CS;8D6@< H;8 54 "AI58D5BC9 1"# E8;BC9< ?:5C9?9GE;4946D5CCR 2D6@ "K H;CC;2D4S V,3..Y" V89H3 bY3 =989 29 H;CC;2 5B8769AH;8:9 5EE8;5:@ BR D4?687:6D4S 658S96 :;<E7698? 6; 9I5C7569K D45 >D?68DB769> H5?@D;4K 95:@ ;H 6@9 -" E;6946D5C ?;C76D;4?3
" E;??DBC9 E585CC9C 5EE8;5:@ 6; 6@9 1"# E8;BC9< D? ?@;24?:@9<56D:5CCR D4 ]DS3 ,3 #@9 E585?D69 4;>9 :89569? -" ?E9:D5CCR:;4?687:69> <9??5S9? >9?DS49> 6; 9I5C7569 5 E;6946D5C ?;C76D;43#@9 >9?DS4 ;H 6@9 <9??5S9K 9GEC;D6D4S 6@9 #^P :@9:O?7<K D?>9?:8DB9> D4 ]DS3 .3 #@9?9 <9??5S9? 589 ?946 6; <54R 658S96 ?98I98?6@8;7S@;76 6@9 F46984963 !;69 6@56 2@DC9 29 :@;;?9 6@9 ?D<EC98 -A1"# :5?9 6; DCC7?68569 6@9 E8D4:DEC9 B9@D4> 6@9 :;>D4SK 6@9 <96@;>:54 B9 9G694>9> 6; :;>9 6@9 !P :;<EC969 .A1"# E8;BC9< 5? 29CCK 5?9GEC5D49> D4 6@9 17EEC9<94658R F4H;8<56D;4 V?99 5C?; @66EWXX22234>39>7XcE585?D69Y3 #@9 <9??5S9 89:9DI9> BR 5 658S96 ?98I98:;465D4? 54 FP @95>98K 5 #^P @95>98K 54> 5 :54>D>569 ?;C76D;4VI5C79? H;8 !#Y3 #@9 ;E9856;8? D4 6@9 \;;C954 9[756D;4 >9698<D49 6@9I5C79 ;H 6@9 :@9:O?7<K 2@D:@ D? D4 6@9 #^P @95>983 #@9 E585?D694;>9 D4U9:6? 95:@ <9??5S9 D46; 6@9 4962;8O 56 6@9 FP C9I9C V]DS3 ,YKBRE5??D4S #^P3 "H698 89:9DID4S 6@9 <9??5S9K 6@9 658S96 ?98I98 I98DQ9?6@9 >565 D469S8D6R ;H 6@9 #^P ?9S<946 BR :5C:7C56D4S 5 #^P
NIF
checksum
ALU
Segmentdropped
Target web server
Network
IP
TCP
{010 ... 11}
Physicalinterface
Parasite node
HTTP
success
Invalid solutionfailure
b
Correct solution
TCP
IP
Network
HTTP
a
{000 ... 00}
ALU
NIF
{000 ... 10}
NIF
ALU
nodeParasite
Valid
Logi
cal i
nter
face
s
due to invalid
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&++,< (5 (82
© 2001 Macmillan Magazines Ltd
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© 2001 Macmillan Magazines Ltd
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
EXAMPLE HTTP - HTML RESPONSE
<html><head><Title> Notre Dame Computer Science and Engineering </Title></head><body bgcolor=white>
<center><img align=middle src=http://www.nd.edu/NDGrafix/NDCSE.gifalt="[ 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>
<H2> If you feel this message is in error, please contact <br><em><a href="mailto:[email protected]">[email protected]</a></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=http://www.nd.edu/NDGrafix/NDBarThin.gif>
<p> <a href=http://www.cse.nd.edu/><img align=top src=http://www.nd.edu/NDGrafix/NDCSEHome.gifalt="[BACK TO ND CSE HOME PAGE]"></a></center> </body></html>
Figure 3: Response from HTTP server
therefore, there is a single checksum for all tests. In the main loop of the algorithm, a test solution is placedinto the data field of the segment. Then the packet is sent, and we wait for an answer.
A correct solution induces a response from the remote node. Therefore, a response means a correctsolution. An incorrect solution is deduced by not receiving a response. This is done by timing out: if aresponse is not received within a certain amount of time it is presumed a negative answer. This is discussedin greater detail in 2 and 4.
4 Implementations
In our implementation a single master node controls the execution of the algorithm. There are severalways to implement the basic algorithm discussed above. The two major choices are (a) concurrency and(b) connection reuse. Regarding (a), the master node can have many computations occurring in the webconcurrently. Each concurrent computation requires a separate TCP connection to a HTTP host.
Regarding (b), before a TCP connection can be used, it must be established. Once established, TCPsegments can be sent to the remote host. When multiple guesses are sent in one connection, it is impossibleto know to which guess a correct solution refers to. For example, suppose guess andare sent one after the other in a single connection. Further suppose that only one solution is correct. Weexpect to get one response back. But we cannot tell to which solution the response refers.
The implementation used in this paper is a prototype that is not designed for efficiency of execution. Inour prototype implement there is no concurrency and each connection is used for exactly one computation.
4