Rusty Russell [ARCHIVE] on Nostr: 📅 Original date posted:2020-10-14 📝 Original message: Joost Jager <joost.jager ...

📅 Original date posted:2020-10-14
📝 Original message:
Joost Jager <joost.jager at gmail.com> writes:
>>
>> > A crucial thing is that these hold fees don't need to be symmetric. A new
>> > node for example that opens a channel to a well-known, established
>> routing
>> > node will be forced to pay a hold fee, but won't see any traffic coming
>> in
>> > anymore if it announces a hold fee itself. Nodes will need to build a
>> > reputation before they're able to command hold fees. Similarly, routing
>> > nodes that have a strong relation may decide to not charge hold fees to
>> > each other at all.
>>
>> I can still establish channels to various low-reputation nodes, and then
>> use them to grief a high-reputation node. Not only do I get to jam up
>> the high-reputation channels, as a bonus I get the low-reputation nodes
>> to pay for it!
>
> So you're saying:
>
> ATTACKER --(no hold fee)--> LOW-REP --(hold fee)--> HIGH-REP
>
> If I were LOW-REP, I'd still charge an unknown node a hold fee. I would
> only waive the hold fee for high-reputation nodes. In that case, the
> attacker is still paying for the attack. I may be forced to take a small
> loss on the difference, but at least the larger part of the pain is felt by
> the attacker. The assumption is that this is sufficient enough to deter the
> attacker from even trying.

No, because HIGH-REP == ATTACKER and LOW-REP pays.

> I guess your concern is with trying to become a routing node? If nobody
> knows you, you'll be forced to pay hold fees but can't attract traffic if
> you charge hold fees yourself. That indeed means that you'll need to be
> selective with whom you accept htlcs from. Put limits in place to control
> the expenditure. Successful forwards will earn a routing fee which could
> compensate for the loss in hold fees too.

"Be selectinve with whom you accept HTLCs from"... it always comes back
to incentives to de-anonymize the network :(

> I think this mechanism can create interesting dynamics on the network and
> eventually reach an equilibrium that is still healthy in terms of
> decentralization and privacy.

I suspect that if you try to create a set of actual rules for nodes
using actual numbers, I think you'll find you enter a complexity spiral
as you try to play whack-a-mole on all the different ways you can
exploit it.

(This is what happened every time I tried to design a peer-penalty
system).

Cheers,
Rusty.