utilities and instructions to run a lightning jamming attackathon
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Vincenzo Palazzo f1046e909b
attck: start basic architecture
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
2024-04-19 13:46:40 -04:00



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In this attackathon, your task will be to write a program that performs a channel jamming attack against a test lightning network. Your goal is to completely jam a routing node for an hour.

Your program should:

  • Accept the public key of the node being attacked as a parameter.
  • Write an attack against the hybrid approach to jamming mitigations which is deployed on the network.
  • Open any channels required to perform the attack, and close them when the attack has competed.

The final deliverable for the attackathon is a run script that downloads, installs and runs your attack in a kubernetes cluster.

Jamming Definition

We're aiming to jam a routing node, which we define as:

The target node is unable to facillitate forwading of HTLCs on behalf 
of of nodes in the network.

Conventionally, this is achieved when:

All of the target node's local(/outbound) HTLC slots are occupied.
All of the target node's local(/outbound) liquidity is occupied.

However, given that we are operating within the context of a specific mitigation, we need to consider the possibility that the attack may try to use the mitigation itself to disrupt quality of service.

In general, our reputation and resource bucketing mitigation may be abused by an attacker to jam a channel if:

All of its general bucket's local(/outbound) liquidity OR slots are occupied.
Peers looking to use the channel have low reputation.

When the attacker manages to successfully sabotage the reputation and fill up general slots, the channel is effectively jammed because peers looking to use the channel do not have access to the projected slots that are reserved for high reputation peers. This may be abused in various ways, and we encourage you to explore them!

Development Environment

The attack you develop will be tested against a warnet running a network of LND nodes that have the jamming attack mitigation implemented* (via an external tool called circuitbreaker).

To assist with local development, we've provided a test network that can be used to run your attacks against. Prerequisites to set up this network are:

Clone the attackathon repo: git clone https://github.com/carlaKC/attackathon

Do not change directory.

The scripts will pull the relevant repositories to your current working directory and set up your network. They expect the attackathon repository to be in the current directory.

Wait for your network to fully come up, then you can start your pod of attacking nodes:

Once you have brought your cluster up, you'll be able to execute your program from inside of the cluster's flagship pod:

  • kubectl exec -it flagship -n warnet-armada -- bash
  • Update run.sh to:
    • Install your program.
    • Run your program using the credentials provided inline.

⚠️ Remember that we're using a fork of LND so you'll need to account for that if you're using common RPC client libraires to have access to endorsement fields (golang client is available here).

The following utilities are available for your convenience:

  • source ./lncli.sh provides aliases for your LND nodes (lncli0, lncli1, lncli2)
  • ./fund.sh funds each of your LND nodes.
  • ./connect_nodes.sh connects the attacking nodes to the network so that they can sync gossip.
  • bitcoin-cli provides access to the bitcoin node that all three LND nodes are connected to.

Network Information

Some relevant characteristics of the network:

  • The reputation system has been primed with historical forwarding data, so nodes in the network have already had a chance to build up reputation before the attack begins.
  • Each node in the network:
    • Allows 483 HTLCs in flight per channel.
    • Allows 45% of its channel's capacity in flight.
    • Allocates 50% of these resources to "general" traffic, and 50% to protected traffic.
  • The graph was obtained by reducing the mainnet graph using a random walk around our target node, and real-world routing policies are used.
  • When you run the attack, the non-malicious nodes in the network will be executing randomly generated payments to mimic an active network.

Some APIS to note:

* Note that endorsement signaling and reputation tracking are fully deployed on the test network, but unconditional fees are not. You should assume that they will be 1% of your success-case fees, and we will account for them during attack analysis.


Attacks will be assessed using the following measures:

  • Did the attack achieve a jamming attack as described above?
  • What was the total cost of the attack, considering:
    • On-chain fees: for channel opens and closes, sending funds between nodes on-chain will node be included for simplicity's sake.
    • Off-chain fees: the sum of fees paid for successful off-chain payments plus 1% of the success-case fees for all payments that are sent to represent unconditional fees.
    • Opportunity cost of capital: for each channel that is opened, 5% p.a. charged on the total capital deployed in the channels, assuming 10 minute blocks.
  • When compared to the operation of the network without a jamming attack, how many honest htlcs were dropped as a result of the attack?


We're trying to break channel jamming mitigations, not our setup itself so please be a good sport and let us know if there's anything buggy! Real attackers won't be able to take advantage of our test setup, so neither should we.

Network Creation

Participants do not need to read the following section, it contains instructions on how to setup a warnet network to run the attackathon on.

Setup Instructions

To get started, you will need to clone the following repos in the same working directory:

  1. This repo
  2. Warnet
  3. SimLN
  4. Circuitbreaker

You will need to provide:

  1. A json file with the same format as LND's describegraph output which describes the graph that you'd like to simulate.
  2. The duration of time, expressed in seconds, that you'd like the setup script to generate fake historical forwards for all the nodes in the network for.
  3. Manually add the alias of the node that you're attacking to attackathon/data/{network name}/target.txt once this script has run.

The setup script provided will generate all required files and docker images for you: ./attackathon/setup/create_network.sh {path to json file} {duration in seconds}

Note that you must run this from your directory containing warnet, simln and circuitbreaker because it moves between directories to achieve various tasks! The name that you give the json file is considered to be your network_name.

Once the script has completed, check in any files that it generated and provide your students with the following:

  1. The network_name for your attackathon.
  2. The attackathon repo (/branch) with all files checked in.

The script currently hardcodes the docker hub account for images to carlakirkcohen and tries to push to it, so you'll need to search and replace if you want to test the full flow.