Onion Routing

I was recently reading some literature about data encryption and I stumbled across an interesting concept. The classic secure communication model is the one where the sender encrypts the message and sends it across the network, which is then decrypted at the receiver’s end. In real life, this is done over several networks and several routers. This method works well because we assume that the routers are completely secure and they do exactly what they are told. Now what if a router is compromised on the path? An attacker will be able to monitor all the traffic that goes through it. Once the attacker gains control of the router, many bad things can happen like decryption of secure messages, false communication, leakage of sensitive details etc. How do we prevent it?   Continue reading