Bankrupting Sybil despite churn

Sybil Fortner

Sybil Nodes as a Mitigation Strategy Against Sybil Attack

Sybil attack is considered one of the most damaged attack that menace structured p2p overlay networks. It’s the most sophisticated node active, used for a variety of illicit activities. A key requirement for these activities is the ability of such malicious user to generate a huge number of node identifiers and possibly choose some of them in order to disrupt availability and integrity in such ...

The Sybil Attack

Large-scale peer-to-peer systems face security threats from faulty or hostile remote computing elements. To resist these threats, many such systems employ redundancy. However, if a single faulty entity can present multiple identities, it can control a substantial fraction of the system, thereby undermining this redundancy. One approach to preventing these “Sybil attacks” is to have a trusted ag...

Sybil-Resistant DHT Routing

Distributed Hash Tables (DHTs) are very efficient distributed systems for routing, but at the same time vulnerable to disruptive nodes. Designers of such systems want them used in open networks, where an adversary can perform a sybil attack by introducing a large number of corrupt nodes in the network, considerably degrading its performance. We introduce a routing strategy that alleviates some ...

Churn, churn, churn: how instability of health insurance shapes America's uninsured problem.

A new analysis of health insurance coverage in America reveals a complex and troubling picture of insurance instability and gaps in coverage over time. Eighty-five million people, or 38 percent of the population under age 65, were uninsured at some point from 1996 through 1999, based on findings from a survey that followed people’s health coverage for four years (Chart 1).The number of people w...