Opened 7 years ago

Closed 7 years ago

Last modified 7 years ago

#1314 closed defect (fixed)

Participating Traffic While in Hidden Mode

Reported by: ExtraBattery Owned by:
Priority: minor Milestone:
Component: router/general Version: 0.9.13
Keywords: Cc:
Parent Tickets: #1192 Sensitive: no


I experienced the following with I2P 0.9.13 and before.

Sometimes I run an I2P router on one of my devices in laptop and hidden mode (both modes at the same time). Even though I am in hidden mode, it can happen that I have a little participating traffic (happens rarely, but does). Not that I bother much, but is this a bug or is this what the router is supposed to do? Could an attacker use this to increase the exposure of someone who is in hidden mode?

The other question is: Why did someone request to have a tunnel routed through me while I wasn't publishing myself for that? Does this indicate a bug in that the I2P router sometimes asks other routers to route traffic, even if said other routers didn't even publish their IP address for that?


Change History (4)

comment:1 Changed 7 years ago by zzz

Component: unspecifiedrouter/general
Parent Tickets: 1192

The old way to be hidden was to put an 'H' in your netdb, and tell everybody you were hidden. That seemed a bad way to go about it.

The new way (implemented several years ago) is just to not publish to the floodfills. But don't put in the 'H'. You still have to exchange RIs with some peers or else it's almost impossible to build inbound tunnels.

So peers that have your RI don't know you are hidden. Sometimes they build a tunnel through you. Should you reject the request (offering more clues) or not?

Improvements may require restricted routes. See parent ticket.

comment:2 Changed 7 years ago by ExtraBattery

Are you saying it's better not to tell others that you are hidden in order to better hide yourself and even blend in by allowing some participating traffic?

I'm not sure what "hidden mode" is really supposed to do. I only read that it "prevents participating traffic", but it doesn't always seem to, so I thought this is a bug.

My reasoning would be:

If "hidden mode" means that your IP address should occur on the least possible occasions (in case someone is looking for your address), then it would imply denying others to build tunnels through you, as each such tunnel increases your exposure. If an attacker has already found your RI and knows your IP address, then you might as well reveal to that attacker that you are trying to hide (offering more clues).

If "hidden mode" means you don't raise any suspicion, you should blend in and behave just like the average router and allow participating traffic.

comment:3 Changed 7 years ago by Eche|on


The hidden mode was a fast, quick and dirty hack to not publish your IP over all places.
It is intendend to not save your IP in the netDB and publish to other I2P routers.
Due to the fact of I2P network routing, your node need to connect to others and these others do know your IP/Node afterwards.
I think building participating tunnels is not a big problem in this case, as your node already did connect the tunnel building issuer ahead.
Hidden mode does in fact NOT hide your IP, it just tries to reduce the places it is found.

comment:4 Changed 7 years ago by zzz

Resolution: fixed
Status: newclosed

There's another reason to reject tunnels when hidden: the previous hop may not be able to find you again, especially if you're an IBGW.

Fixed in 80add9a5a7cefafcc83aec95134256bf7d4468e4 0.9.13-9

Last edited 7 years ago by zzz (previous) (diff)
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