The below is a direct excerpt of Marty's Bent Issue #1253: “Channel jamming research you should read.” Sign up for the newsletter here.
Channel jamming makes forwarding payments near impossible
Here's a great website from Antoine Riard and Gleb Naumenko that breaks down the channel jamming problem on the Lightning Network. I highly recommend you freaks check it out if you want to get a better understanding of one of the bigger attack vectors of the Lightning Network and how developers are thinking about it. In short, a channel jamming attack is a denial-of-service attack that allows a nefarious actor or actors to prevent routing nodes from forwarding payments within a channel. Increasing the amount of failed payments and reducing the reliability of the lightning network overall in the process. Not ideal, but totally possible at the moment.
This may not make you feel great, but it is the reality we find ourselves in today. While many see incredible promise in the Lightning Network, myself included, it is also important that we be upfront with its shortcomings so that we can attempt to fix them as we build out the network. Trying to pretend they don't exist won't be beneficial in the long run. This is why we're extremely fortunate that smart individuals like Riard and Naumenko, among many others, are out there doing very important research, brainstorming and testing to discover ways these problems can be solved.
On this site you'll be able to read into some of the proposed solutions that exist for the channel jamming problem, which include changing the channel structure by using a tree of commitments, actively defending against an attack as it's happening by opening other channels (doesn't seem ideal), and the concept of bucketing different slots across small and large denomination of sats, isolating channels of a particular size. It doesn't seem like there's consensus on whether or not any of these solutions are ideal or practical at scale. However, this website is a great jumping off point to stoke conversation among developers and users alike who would like to solve this problem. More awareness leads to more minds thinking about these problems and that's a good thing in the long run.
Kudos to Riard, Naumenko and every other developer working to solve these problems. The work that they are doing is very important and could prove to make humanity more free and the world a better place in our lifetime.
Onward!