Bitcoin Lightning-independent developer Just Jager has identified the use of a micropayment network that can lead to infiltration into a channel with minimal effort and minimal cost.

However, he said that he did everything to find a possible solution.

Yager points out that the attack can be carried out on wumbo channels, which basically allow larger transactions between mutual parties on the Lightning Network.

The Wumbo channel removes the maximum total bitcoin that can be stored in a regular lightning channel, which is around $ 1,760 at current prices. It is also removed virtually. $ 450 is a one-time payment limit.

Jagger said that wumbo channels can be intercepted because a channel can not contain more than 483 hash and time-locked (HTLC) nodes at any one time, regardless of capacity. Thus, the attacker sends itself 483 small bumps while following HTLC, enough to disturb the channel for up to two weeks.

The developer explained that this can be achieved by using the maximum track length to add cycles and multiple contracts to quickly reach this amount with a small start-up cost, 5.8 million satoshi in this example.

If the writer is lucky, they only need to send 54 payments to do this. A small channel drives double-digit bitcoin amounts out of business.
He added that to solve this problem, he launched a new Lightning node project firewall called Circuit Breaker. When asked if this “sad attack” is the largest unresolved attack on LN to date, he added;

It depends on how you define the elder. There are other attacks that can make you lose money and look even worse. But this is one of the biggest problems if you do not know how to solve it.
With wumbo channels, a user can indicate that he wants to send more BTC than usual and find the node he wants to receive. Ordinary lightning users who send small payments will not hurt, but it is a much better option for business and corporate payments.

Wumbo channels are becoming increasingly popular, and Bitfinex was the last to announce its support;

The word “wumbo” comes from SpongeBob SquarePant’s animated series and refers to the idea that both parties must agree on a “wumbo” together for a transaction to take place.

Source: CoinTelegraph