How to prevent Sybil Attacks without PoW/PoS
Preventing Sybil Attacks in a Decentralized Oracle Network, without relying on Proof of Work or Proof of Stake… and not die trying!
In this article, we’ll discuss the challenge of preventing Sybil attacks on Witnet, the Decentralized Oracle Network, without relying on Proof of Work (PoW) or Proof of Stake (PoS). Sybil attacks are an Achilles’ heel for decentralized protocols, so we’d like to share our process and design choices to deal with them.The attack of the “Sybils” So who’s Sybil?
The term “Sybil attack” is in reference to the 1973 book, Sybil — a case study of a woman diagnosed with a dissociative identity disorder.
The mechanisms of the attack are as follows: attackers aim to undermine a network by creating numerous fake identities. To an observer, these identities appear as separate users, but in reality, they are all controlled by a single entity. As a result, the attacker has a significant influence on voting power and could collapse or corrupt the network.
Sybil attacks are often confused with Eclipse attacks. However, in the latter, fake identities do not attempt to mislead the network entirely; instead, they corner individual nodes on the network by monopolizing all their P2P connections. By isolating specific elements, the attack can portray a fake network state to them. In summary, Eclipse attacks affect a small portion of a network, whereas Sybil attacks violate the entire network. You can read more about Eclipse attacks here:How decentralized consensus algorithms deter Sybil attacks
Proof of Work (PoW), utilized by Bitcoin’s network, is the go-to model for Sybil resistance. To be rewarded, each identity on the network must carry out a non-arbitrary and equal amount of computational work. In other words, every Sybil identity must perform as much work as every honest identity, thus making a Sybil attack prohibitively expensive.
In Proof of Stak...