Hi Kailash.
Thanks for your time to read the article.
As I mentioned in the article, it is more than 50% dishonest or malicious nodes that are required to take over the network. Just think it in this way — Imagine you and your 4 friends decide to point of a person cheating in the group. If at least 3/5 people in your group are honest, then the cheater will always be found. However, if 3/5 are dishonest, then cheater will not be found because majority will be pointing to the wrong person as cheater. I hope this answers your first question.
It is possible that majority of the network becomes dishonest. One of the cases could be if majority of the nodes are owned by single entity like let’s say there is a large mining pool and the computing power of that mining pool is more than 50% of the computing power of the network and if that mining pool becomes dishonest then it can take over the network. Basically, with 51% attack, it is meant that controlling more than 50% of the network’s compute power. I hope this answers your questions.
Once again thank you so much for taking out time to read the article and feel free to ask any further queries.
Best,
Sidharth
