Question

Since bus-topology network uses a shared medium, eavesdropping is inevitable. (But we could prevent the message from being understood by encryption).

Only star-topology network can prevent eavesdropping for good.

Is this true?

Thanks.

Answer 1

No, not entirely true, anyone with enough access to the hub itself can still eavesdrop on all conversations.

Star topology stops the nodes themselves from eavesdropping (assuming the hub doesn’t do something stupid like broadcast everything) but I’d rather have an uncomplicated wire as my single point of failure than some massively complex piece of network hardware 🙂

Then, if you want security, that’s handled in the upper layers of the network stack. The physical layer need not be concerned with that.