TOR

THE ONION ROUTER

DHARAMVIR BISHT

Who needs AnonymityGovernment Organization ?Private Organization?HackersAnd yes !!!Criminals? But they already have it What About YOU

TOROnion routing is an anonymous communication technique over a computer network. Messages are constantly encrypted and then sent through several network nodes called onion routers which creates a circuit of nodes

Anonymous Connection and Onion RoutingWho is Talking to Whom ?In a Public Network>Packet headers identify recipients>Packet routes can be tracked

Traffic Analysis Reveals Identities>Who is searching a public database?>Which companies are collaborating?>What are you talking to via-Email?>What do you shop online? ObjectivesDesign an infrastructure that>Makes traffic analysis hard>Separates identification from routingOur goals is anonymous connections, not anonymous communication.An infrastructure, Onion Routing, has been implemented.

Steps for Onion Routing> Define the route>Construct the anonymous connection>Move and encrypt the data through the connection>Destroy the anonymous connection Tor in brief 1/3

Step 1: Alices Tor client obtains a list of Tor nodes from a directory serverTor in brief 2/3

Step 2: Alices Tor client picks a random path to destination Server. Green links are encrypted, red links are in the clear.Tor in brief 3/3

Step 3: If the user wants access to another site, Alices Tor client selects a second random path. Again, green links are encrypted, red links are in the clear.Example

Let onion routers 4, 3, and 5 be randomly selected by the onion proxy

Onion Sent by Client to 4

Router 4 will decrypt the E{4u} layer usingIts private key, to find the next routers Ip address, and encrypted

Onion Sent by 4 to 3

Router 3 will decrypt the E{3u} layer usingIts private key, to find the next routers Ip address, and encrypted

Onion Sent by 3 to 5

Router 5 will decrypt the E{5u} layer usingIts private key, to just find unencrypted data packet Data Sent by 5 to TargetTOOLSTOR BROWSER TOR GATEWAYTOR WORK STATIONJANUSVM

Referenceshttps://www.torproject.org/about/overview.html.enhttp://www.onion-router.net/http://ntrg.cs.tcd.ie/undergrad/4ba2.05/group10/indexhttp://en.wikipedia.org/wiki/Onion_routing