Sybil Attacks

Social networks take over the world

Recent statistics reveal that over ‘1 billion users are connected through online social networks’ (Chbeir, 2013, n. p.), which is indeed, a staggering figure that calls for our attention. Social networks are exceeding our expectations in the ways we connect, communicate and understand the computerized world of today. However, as the numbers get higher, so should our awareness and understanding increase for the vulnerabilities and threats such networks pose given our excessive interchange of data and identities.

Sybil Attacks                ‘A hidden connection is stronger than an obvious one.’ – Heraclitus

All distributional systems, including social networks, are sensitive to Sybil attacks, which are otherwise known as clone attacks in computer science. The most evident intrusion of counterfeit profiles is seen in social networking sites, where users unintentionally consign their data and ‘identities’ to unknown systems or to possible ‘attackers’ in this case. A Sybil attack is the corruptive act of stealing and manipulating identities in the spheres of networking systems. The attack is established when a ‘malicious user takes on multiple identities and pretends to be multiple, distinct nodes in the system’ (Yu, Kaminsky, Gibbons, & Flaxman, 2008).

Source: Social Media apps [Digital Image], 2013.

Source: Social Media apps [Digital Image], 2013.

There are two main types of systems that are targeted: systems with a trusted authority, which are more reliable, and decentralized systems that are more vulnerable to Sybil attacks. The attackers are less likely to enter trusted systems given the requirement of various security codes and in advance payments. However, there is a certain drawback with the user’s probable refusal to provide the system with confidential and private information. On the other hand, experts are more focused on identifying specific approaches and strategies to accommodate users and prevent Sybil attacks in decentralized systems. As a result, experts and researchers have proposed the inauguration of IP addresses and their close link to an identity. Nonetheless, this strategy proves to be short-term and an ineffective solution given that ‘malicious users can easily harvest IP addresses’ (Yu et al., 2008). As an alternative to these two major systems, experts introduce Sybil Guard, a new defence scheme. In addition, another solution is seen in the problem-solving stratagem to protect identities and systems which will nevertheless prove challenging, both to users and experts alike. Part 2: Sybil Guard or Puzzles?


Yu, H., Kaminsky, M., Gibbons, P. B., & Flaxman A.D. (2008). SybilGuard: Defending against sybil attacks via social networks. IEEE/ACM Transactions on Networking, 16(3), 576-589.

Chbeir, R. (2013). Security and privacy preserving in social networks. Dordrecht, Netherlands: Springer.


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