Parasitic Computing Presented By Jay Kumar Vinay Kumar

Parasitic Computing Presented By Jay Kumar Vinay Kumar Sharma Sushil Kumar Mishra

Parasitic Computing INTRODUCTION • A concept by which one can use the resources of other machines that are connected on the Internet. • A form of distributed computing • Used for solving complex computational problems • Exploits standard set of communication protocol on Internet

Parasitic Computing How it differs from other? • Cluster Computing Ø In cluster computing many computers pool in their resources willingly. Ø Parasitic computing does not require the willingness of any target machine

Parasitic Computing How it differs from other? NOT a Cracking

Parasitic Computing Internet Communication When user selects a URL • Actions at sender Ø Open a TCP connection to a webserver Ø Issue a HTTP request over TCP connection Ø TCP message is carried by IP • Actions at receiver Ø Receive message through IP Ø Validate checksum at TCP q Validated pushed to HTTP q Not validated discard the packet

Parasitic Computing Internet Communication Sender Receiver HTTP TCP IP IP NET

Parasitic Computing Proof of Concept Ø Solve the SAT problem Ø NP-Complete Ø Usually solved by testing several candidate solution Ø Each candidate solution can be examined in parallel

Parasitic Computing TCP Checksum • • Sender breaks message into 16 bit words These words are added together The result is inverted and sent with message Receiver breaks message into 16 bit word All words are added together If the result is all ones, the message is valid Otherwise, message is invalid

Parasitic Computing TCP Checksum

Parasitic Computing 2 -SAT Problem • 2 -SAT problem is to find a truth assignment to these variables that makes a formula of this type true • It is a boolean expression with a special restricted form: a conjunction of clauses

Parasitic Computing Solving 2 -SAT Problem • Send a specially created TCP packet containing a possible solution to a targeted machine • 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

Parasitic Computing Creating parasitic messages • Assign possible values to variables • A mechanism to create a packet that has to be sent to the target machine for verification • Packet consist checksum and variable string

Parasitic Computing Creating parasitic messages

Parasitic Computing Prototype of Parasitic Computer

Parasitic Computing Problem for Parasites • Several computational cycles are taken to process the possible solutions • Possibility of false negatives • Possibility of false positives • Ethical dilemma

Parasitic Computing Problem for Target M/C • Delay 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

Parasitic Computing 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. nd. edu/~ccrowell/Parasitic%20 Computing. pdf Ivars Peterson, Sneaky Calculations, Science News 160, 17 Nov 2001.