In a private blockchain, a new node cannot get automatically connected to the private network. That's why the network is private.

Regarding authentication, the unique --networkid of your network and your genesis file act as a first level of authentication factors to your private blockchain network. In other words, a new node cannot be added to the network unless it has a copy of the genesis file and knows the networkid.

Even if a node is aware of both these attributes, it won't be a part of the private network unless it's manually added (through it's enodeURI) as a peer to one of the nodes (of the private network) through the addPeer() function. There is no automatic peer discovery in a private blockchain network.

If you think that all the aforementioned tasks could be possibly carried out by an attacker, you can enable the --nodiscover option and use the --maxpeers option to limit the no. of connections.

In a private blockchain, a new node cannot get automatically connected to the private network. That's why the network is private.

Regarding authentication, the unique --networkid of your network and your genesis file act as a first level of authentication factors to your private blockchain network. In other words, a new node cannot be added to the network unless it has a copy of the genesis file and knows the networkid.

Even if a node is aware of both these attributes, it won't be a part of the private network unless it's manually added (through it's enodeURI) as a peer to one of the nodes (of the private network) through the addPeer() function. There is no automatic peer discovery in a private blockchain network.

If you think that all the aforementioned tasks could be possibly carried out by an attacker, you can enable the --nodiscover option and use the --maxpeers option to limit the no. of connections.

In a private blockchain, a new node cannot get automatically connected to the private network. That's why the network is private.

Regarding authentication, the unique --networkid of your network and your genesis file act as a first level of authentication factors to your private blockchain network. In other words, a new node cannot be added to the network unless it has a copy of the genesis file and knows the networkid.

Even if a node is aware of both these attributes, it won't be a part of the private network unless it's manually added (through it's enodeURI) as a peer to one of the nodes (of the private network) through the addPeer() function.

If you think that all the aforementioned tasks could be possibly carried out by an attacker, you can enable the --nodiscover option and use the --maxpeers option to limit the no. of connections.

In a private blockchain, a new node cannot get automatically connected to the private network. That's why the network is private.

Regarding authentication, the unique --networkid of your network and your genesis file act as a first level of authentication factors to your private blockchain network. In other words, a new node cannot be added to the network unless it has a copy of the genesis file and knows the networkid.

Even if a node is aware of both these attributes, it won't be a part of the private network unless it's manually added (through it's enodeURI) as a peer to one of the nodes (of the private network) through the addPeer() function. There is no automatic peer discovery in a private blockchain network.

If you think that all the aforementioned tasks could be possibly carried out by an attacker, you can enable the --nodiscover option and use the --maxpeers option to limit the no. of connections.