Sybil Attacks
One-way security can break down is in a Sybil attack. Named after the case study of a woman with multiple personality disorder, a Sybil attack is a type of security threat when a node in a network claims multiple identities. Most networks, like a peer-to-peer network, depend on on assumptions of identity, where each computer denotes one identity. A Sybil attack occurs when an insecure computer is hijacked to claim multiple identities. Problems arise when a reputation system (such as a file-sharing reputation on a torrent network) is tricked into thinking that an attacking computer has a disproportionally large influence. Similarly, an attacker with many identities can use them to act maliciously, by either stealing information or troublemaking communication. It is important to recognize a Sybil attack and note its danger in order to protect yourself from being a target. First defined by Microsoft researcher John Douceur, a Sybil attack relies on the fact that a network of comp...