Question

In the Bitcoin blockchain, a node may attempt to perform verification of the existence of a particular transaction by querying its nearby nodes/peers. Examine the attacks that may be encountered by the node.

Answer 1

There are mainly two types attacks encountered by the nodes they are:

Eclipse attack

It is one of the most common attack carried on the node in a peer to peer network it is a type of attack in which attacker obscurs or hinders the working of nodes in order to create a disruption to carry out a possible bigger attack the attacker make sure that all the target's connection are made to attacker's controlled nodes and the attacker basically hijacks the pper to peer netywork by flooding the network with its IP and when the user connect with one of those IPs then the user will be under the control of the attacker and attacker can feed any data to the user and can possibly harm the user 's syatem in any way possible.

Sybil attack

This type of attack is also a great threat to the nodes because in a blockchain netwrok there is no trusted nodes so each and every node's request is sent to many nodes and then sybil attack comes into play .It is a type of attack in which an attacker basically try to take control over the peer to peer network by creating multiple nodes of its own which is somewhat similar to a person making multiple fake profiles in FB however in this attack the attacker creates so many fake nodes of its own which outnumbers the real ones and then they are able to refuse to receive or transmit blocks and thus they are successful in blocking other users from a network and it closes up all the transaction of a user.