What is Onion Routing?

1.Onion routing is defined as a method of communication anonymously i.e without revealing the users’ identity over a computer network. In this type of network the messages which are sent and received stays encrypted. The encrypted messages or other data is transferred through various nodes of a network which are known as onion routers (Chen et al., 2015). Onion routers communicate among themselves over Transmission control protocol(Sakai et al., 2016,). The process of onion routing is based on the technique of hiding the source i.e sender of data or message of a packet data instead of the content of data from the network tracking authorities (eg. Government or security agencies). Onion routing therefore protects data from the network traffic analysis type of attack on the encrypted data. There are some routers which serve as entry funnels and some are as exit funnels. The process of onion routing is based on the usage of public key cryptography which is a technique that encrypts each and every layer of onion and allows only the intended receiver of data to decrypt it.

2.The onion routing is used for the anonymous communication by the users where the information sent over the network stays hidden and the senders’ identity also stays covered. The security agencies and defence forces use this technique for communication to keep sensible data safe and secured from tracing the sender and receiver(Zhou et al., 2013). NSA uses vulnerability of TOR to track illegal activities done in deep or dark web. Internet users has been using onion routing to send sensible data such as banking details and passwords to specific receiver over the network. Important details related to research and findings are sent via onion routers to safeguard them from the hackers and network observers. The educational institutes use this for publication of results and question papers to prevent them from leaking.

3.The onion routing method has been widely used by the criminals to stay anonymous and carry on illegitimate activities of sending data to stay hidden from government and security agencies. The trading of crypto currencies and other communications related to monetary fraud is done using onion routing technique by the fraudsters. The terrorists use this to conduct terrorism related crimes by communicating internationally. The traffic analysis is used by the hackers to interrupt the message when it travels through a network to steal information of users. The cybercriminals can hack the exit note and get the raw data transferred over the network. It is a major vulnerability of TOR which is often used by the hackers(Doshi and Jinwala 2013). The cybercriminals use this for communication among themselves and exchange of information. 

Why Onion Routing is used?

4.The process of onion routing can be cracked by the technique called timing analysis. In onion routing the sender’s identity is not revealed because if an intermediate router is hacked it will only reveal about the immediate routers but not the original sender(Biondi et al., 2013). The conventional internet service is vulnerable because the internet service provider can trace the connections of two users but in onion routing an obscure path is created between the two computers in such a way that there is no direct connection between the user and a website but there are many lines of communication or connections between the computers of the network. The process of traffic analysis can track the messages transmitted over the network by onion routing. Traffic analysis method is an onion routing decryption process which searches those series of connections constructed and used by a potential creator of the data or message. Thereafter it matches the traffic data and tracks the traffic which is transferred through network. Although in onion network the message which is being sent is transmitted within many stages of encryption process, the job of the exit or final node, as the final or exit node of the network chain, is to decrypt the last layer and deliver the message to the recipient of the message. A hacked exit node is therefore be able to get the raw information which is being transferred, potentially leakble  data including email or computer passwords, private messages, bank account details like account numbers or net banking passwords, e-wallet passwords and other forms of personal information. Dan Egerstad, who was a Swedish researcher, who found a way to hack this kind of information and executed such hacking attack to gain access the passwords of many email accounts of officials which are related to foreign embassies of different nations. Exit node vulnerabilities are same as of those on unsecured wireless networks like wifi network, where the information which is being transmitted by a user on the network may be hacked by another user of the same network or by the router administrator. Both the problems are solved by using a safe end-to-end connection system like SSL (security sockets layer) or secure HTTP (HTTPS- hypertext transfer protocol secured). If there is end-to-end encryption between the sender and the recipient, then it is not even possible for the last intermediary router can get the original content or message.

Illegitimate use of Onion Routing

5.The process of onion routing helps to keep privacy online by hiding information of the sender and receiver. The onion routing hides the identity of the sender of the message by using various onion routers which even when is compromised only gives information about the immediate nodes and not the source of message (Haraty and Zantout, 2014). The onion routing is thus useful for the anonymous communication and acts as a VPN (virtual private network) for the users of the network. The users send the anonymous data without any trace of traffic tracking. The onion routing is therefore a great technique for the cyber criminals and security agencies to keep their data safe and tracing proof.

6.The onion routing is both used for legitimate and illegitimate purposes by cybercriminals and security agencies, government organizations. The TOR technology is so designed that the routers even when compromised only gives out the content of packet data instead of the sender of the data. The same technology is used by both the criminals and government for legitimate and illegitimate processes. Cybercriminals use this technology to keep their data away from the network observers’ reach. The use of onion routing is done by the military agencies to send and receive data securely without any risk of stealing of data from enemies. The security agencies use this to share the security related details to prevent leakage and potential threats. The research institutes use this to transfer data from one laboratory to other and researchers use this to share information among themselves for better collaboration and sharing of ideas related to research. The onion routing is also used by space research organizations and for keeping the research data such as satellite launching data secured. Onion routing though mostly used for illegitimate processes but it is also used for legitimate processes to a large extent. 

References

Chen, C., Asoni, D.E., Barrera, D., Danezis, G. and Perrig, A., 2015, October. HORNET: High-speed onion routing at the network layer. In Proceedings of the 22nd ACM SIGSAC Conference on Computer and Communications Security (pp. 1441-1454). ACM.    

Sakai, K., Sun, M.T., Ku, W.S., Wu, J. and Alanazi, F.S., 2016, June. An analysis of onion-based anonymous routing for delay tolerant networks. In Distributed Computing Systems (ICDCS), 2016 IEEE 36th International Conference on (pp. 609-618). IEEE.

Zhou, P., Luo, X., Chen, A. and Chang, R.K., 2013. SGor: Trust graph based onion routing. Computer networks, 57(17), pp.3522-3544.

Doshi, N. and Jinwala, D., 2013. AB-OR: Improving the Efficiency in Onion Routing Using Attribute Based Cryptography. In Computer Networks & Communications (NetCom) (pp. 425-432). Springer, New York, NY.

Biondi, F., Legay, A., Malacaria, P. and W?sowski, A., 2013, January. Quantifying information leakage of randomized protocols. In International Workshop on Verification, Model Checking, and Abstract Interpretation (pp. 68-87). Springer, Berlin, Heidelberg.

Haraty, R.A. and Zantout, B., 2014. The TOR data communication system. Journal of Communications and Networks, 16(4), pp.415-420.