Sybil attack

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As Sybil attack is referred to in the computer security an attack on peer-to-peer - networks by creating false identities . The attack can aim to influence majority votes and the network organization, to slow down the network in a targeted manner, to disrupt the networking in the network, or to eavesdrop on communication between other peers .

The name comes from the 1973 book Sybil by Flora Rheta Schreiber , which describes the case of a woman with dissociative identity disorder . The name was suggested by a Microsoft Research employee , Brian Zill.

An example of a Sybil attack on a P2P network is documented for the Tor network .

functionality

An attacker creates or steals a large number of aliases and can thus appear like several different peers. This gives the attacker a disproportionately large influence in the network. The susceptibility of systems to Sybil attacks depends on various properties, such as how easily identities can be generated, as well as the opportunities for participation have participants who have little or no trust from other trustworthy participants.

As Sybil-free (Engl. Sybil-free ) are referred to systems in which the absence of participants Sybil identities can be guaranteed with.

Prevention

Sybil attacks can be prevented, for example, by means of central certification or authentication instances , which, however, may come at the expense of any desired anonymity in such systems. There are also approaches to prevent Sybil attacks at least to a certain extent by exploiting the networking in social graphs.

Individual evidence

  1. ^ John R. Douceur: The Sybil Attack . In: International workshop on Peer-To-Peer Systems . 2002 ( http://research.microsoft.com/pubs/74220/IPTPS2002.pdf online [PDF; accessed June 29, 2015]).
  2. ↑ Tor security advisory: "relay early" traffic confirmation attack. The Tor Project, July 30, 2014, accessed June 29, 2015 .
  3. ↑ Leonardo A Martucci, Markulf Kohlweiss, Christer Andersson, Andriy Panchenko: Self-certified sybil-free pseudonyms . In: Proceedings of the first ACM conference on wireless network security . 2008 ( http://www.cs.kau.se/~leonardom/pdf/LAMartucci_SelfCertified_SybilFree_Pseudonyms.pdf online [PDF; accessed on June 29, 2015]).
  4. ↑ Haifeng Yu, Michael Kaminsky, Phillip B Gibbons , Abraham Flaxman: Sybilguard: defending against sybil attacks via social networks . In: ACM SIGCOMM Computer Communication Review . 2006 ( http://virtualhost.cs.columbia.edu/~danr/courses/6772/Fall06/papers/sybil.pdf online [PDF; accessed July 2, 2015]).