• Channel jamming is a threat to the Lightning Network, as it can be used to deny-of-service attack nodes on the network.
• Lightning developer Antoine Riard proposed a formal specification for a solution to this problem in August.
• The proposed solution involves the use of a Chaumian ecash token to create a sort of reputation scoring system for users routing payments through nodes without compromising privacy.
Channel jamming is an issue that has been looming over the Lightning Network for some time now. It can be used as a denial-of-service attack on nodes on the network, locking up liquidity and preventing them from earning fees from forwarding payments. This is a major issue that needs to be addressed before Lightning can reach its full potential. Fortunately, last month, Lightning developer Antoine Riard proposed a formal specification for a solution to this problem.
In August, Riard and Gleb Naumenko published research looking at the general problem of channel jamming, as well as a number of different solutions that could be used to mitigate or solve it. One of these solutions was a form of anonymized credentials that nodes could use to build a sort of reputation scoring system for users routing payments through them without having to dox or associate that reputation with a static identifier that would negatively impact peoples’ privacy. This solution has now become the formal protocol proposal made by Riard last month.
The core of the idea is a Chaumian ecash token. These are centralized tokens issued by a mint authority in a way that prevents the issuance of a token from being correlated to the redemption of a token later. This is done by signing a token in a blinded way, allowing the receiver of the token to unblind it without invalidating the signature. The issuer can then verify it is a valid token and redeem it for a value.
In this proposal, the Chaumian token would be used to create a reputation system. When a payment is made, the sender would include a Chaumian token along with it, which the receiver can redeem with the mint authority. This allows the receiver to prove that the sender has made a payment and to associate a reputation score with the sender. This score can be used to determine if a user is a reliable source of payments, as well as to detect channel jamming attempts.
The proposed solution is still in its early stages, and it is not clear yet how it will be implemented. However, it does represent an important step forward in solving the problem of channel jamming. If successful, it could be a major step forward for Lightning, allowing it to reach its full potential as a payment network.