Attacks on peer-to-peer networks
Many peer-to-peer networks are under constant attack by people with a variety of motives.
Examples include:
* poisoning attacks (e.g. providing files whose contents are different from the description)
* polluting attacks (e.g. inserting “bad” chunks/packets into an otherwise valid file on the network)
* freeloaders (Sometimes known as ‘Leechers’) (users or software that make use of the network without contributing resources to it)
* insertion of viruses to carried data (e.g. downloaded or carried files may be infected with viruses or other malware)
* malware in the peer-to-peer network software itself (e.g. distributed software may contain spyware)
* denial of service attacks (attacks that may make the network run very slowly or break completely)
* filtering (network operators may attempt to prevent peer-to-peer network data from being carried)
* identity attacks (e.g. tracking down the users of the network and harassing or legally attacking them)
* spamming (e.g. sending unsolicited information across the network- not necessarily as a denial of service attack)
Most attacks can be defeated or controlled by careful design of the peer-to-peer network and through the use of encryption. P2P network defense is in fact closely related to the “Byzantine Generals Problem”. However, almost any network will fail when the majority of the peers are trying to damage it, and many protocols may be rendered impotent by far fewer numbers.