Having to log into every node using a password is extremely clunky and awful! Instead, I'm going to define certain nodes as entry nodes, and these ones have master passwords. You can log into an entry node from anywhere.
The only way to log into non-entry nodes is to jump to them from an adjacent node. So I'll call them jump nodes, even though you are allowed to jump into an entry node.
A master password will continue to be something like 'dog erroneous waterfall end'.
A jump code will be one word, or a short number. Something like 'din' or '419'.
Because I've generally been against tracking player accounts, I was having trouble -- I wanted shorter passwords, but I didn't know how to prevent brute force attacks!
Now, it's simple: a brute force attempt will be punished by temporarily blocking the jump path. If you're attempting to guess a node's jump code from an adjacent node, you only get a few guesses -- somewhere between 3 and 10 -- and if you hit that maximum, the destination jump node will block jump access from the source jump node for a period of time.
Alternatively, the punishment can involve your entry node (which are now rarer and more valuable! you really don't want someone getting into your entry node), or some sort of energy cost for attempting a jump (and failing?).