Defense over Protocol Attacks

Source: https://witnet.io/about

The most frequent attacks aimed at PoW and PoS consensus mechanisms in blockchains have been thoroughly analysed in recent years, but how does a reputation system based blockchain defend against these attacks? In our blog in Medium you can find specific explanations, but in summary:

• Sybil attacks: The reputation system works very well against this attack since it requires the sybils to work on the network to gain sufficient influence. In addition, a collateral fee is required when solving a data request, making the attack economically inviable.

• Eclipse attacks: In order to avoid an attacker monopolizing all the connections of a node, a P2P bucketing system has been implemented. More details can be found in this post of Medium.

• Bribery attacks: The implementation of the collateral fee makes any bribe very expensive, for more information, take a look on this post.

• Majority attacks: The implementation of Witnet guarantees that in order to perform a majority attack, the attacker would need to hold 51% of the total reputation. This is an extremely unlikely scenario, even where reputation is pooled.

• DDoS attacks: Witnet implements Dandelion to obfuscate the relation between IPs and Public keys, making DDos attacks near impossible.