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Onion Routing uses a flexible communications infrastructure that prevents traffic from being analyzed and eavesdropping from occurring. The way it works is by separating routing from identification techniques. In other words, any identifying information is removed from the data stream (Syverson, 2005).
The structure is created by wrapping a plaintext message in layers of encryption. Just as an onion has layers that peel away, this wrapping is successively pealed away as the wrapped message is passed through from one router to the next. The message is viewable only by the sender and the recipient and perhaps even the last node, unless end-to-end encryption is used (Joshi, 2012).
For example, in a packet switched network, packets use a header for routing and the payload confers the data. The header is visible to the network and anyone watching the network; it tells where the packet originated and where it is going. Encryption and obscuration do not prevent identification.
Onion Routing allows for anonymity by using socket connections, which are placed below the application layer and depend upon the application. Proxies are use to make the data stream anonymous. For example, an application will establish a socket connection to an Onion Routing Proxy. The proxy then links anonymously to its destination via other Onion Routers.
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An Onion Routing network is resistant to both network eavesdropping and traffic analysis because it blocks the normal identifying characteristics of packet data within the public network using layers of protection. As the data...
As each layer is removed, the data has a different appearance for anyone watching; it would be like someone following a suspect who keeps changing his appearance at every depot station: he is impossible to track unless one knows in advance what the suspect will be changing into. Since only the suspect knows that, the tail cannot possibly follow. In the Onion Routing network, anonymity is preserved in the same way. Eavesdropping is prevented due to the encryption that takes place between Onion Routers. Thus, even if one router is compromised, eavesdropping is still not likely. Only if every router on the path is compromised will data be possibly tracked, and the likelihood of such occurring is very low.
Each router is only able to know the identity of the adjacent router along the connection route. Data is encrypted in layers along the way so that at each router, one layer is removed. Since data appears differently at each Onion Router along the way, the information cannot be tracked. All information about the connection is cleared from each Onion Router when the connection is ended. Thus, anonymity is preserved over a public network.
However, a local eavesdropper could see that someone has sent or received a message—but the local eavesdropper won’t be able to determine the identities of both the sender or the receiver: only one or the other (Joshi, 2012).
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Tor is a “circuit-based low-latency anonymous communication service” that is a…
