Late on Sunday night, researchers found a serious validation flaw in LND, a well-liked version of the Lightning Network for Bitcoin supported by Lightning Labs.
The LND problem impacted the way Lightning nodes worked and made it impossible for LND users to leave the layer 2 Lightning Network and enter the mainnet.
While examining the restrictions of the Bitcoin Scripting Language, a programming language for Bitcoin, researchers came upon the LND issue.
Watchtowers are independent services that keep an eye on the publicly accessible Bitcoin Lightning Network and let consumers demand compensation for improper actions.
When closing the channel and leaving the network into mainnet Bitcoin, they often rely on one counterparty to tell the truth about the final balance of bitcoin in each other's possession.