IN 2018, THE NUMBER OF AVAILABLE NODES IN THE BITCOIN NETWORK DECREASED BY 19%
According to the Bitnodes, the number of available nodes in the bitcoin blockchain network decreased by 19%, from 11845 to 9597, for the current year. At the same time, the number of unavailable nodes fell by 33%, from 98000 to 65500. The fact of reducing the number of nodes in the network increases the possibility of “51% attack”, although the probability of such a scenario remains minimal.
An accessible node in the Bitcoin network can send and receive connections, while an inaccessible node can only establish outgoing connections, but does not accept incoming connections, because it is “closed” by a firewall, Tor, or a mechanism called “network address translation” (NAT) that allows the IP addresses of transit packets to be translated.
In theory, the presence of a large number of inaccessible nodes in the blockchain is a good news, because they make the network more secure, creating obstacles to hackers, and also increase resistance to deanonimization. Available nodes also play an important role, because they can be full nodes, where an entire copy of the blockchain with the history of all transactions is stored.
The drop in the number of nodes in the network, theoretically, can lead to increased centralization of the network, which is, it brings the chances of “51% attack” or “double spending”. Although the probability of implementing such scenarios remains low, the decline in the number of bitcoin network nodes demonstrates the impact of the “bearish” trend in the cryptocurrency market on the security of the blockchain.