At the Bitcoin Association of Hong Kong’s Lightning Hack Day on March 31, 2019, Bitcoin developer Felix Weis presented a successful demonstration of his Lightning-enabled plugin for a Bitcoin ATM.
Weis, who identifies himself on Twitter[1] as a “bitcoin traveler and freelance developer,” demonstrated a Lightning-driven withdrawal using a 20 Hong Kong dollar (HKD) bill and a mobile bitcoin wallet on his cell phone.
The software plugin was built in Java over the course of the hackathon weekend.
How Does It Work?
During the demonstration[2], Weis’s ATM — for which he designed the Lightning-enabled software but not the physical machine — offered the option to receive bitcoin either on-chain (requiring a roughly 10-minute confirmation time) and then prompted Weis to scan his Lightning invoice. During the demonstration, Weis pointed out that the maximum withdrawal limit is 20 HKD, roughly $2.55 USD or 0.00061893 BTC. Leo Weese, who organized the hackathon, was able to make a similar withdrawal[3].
Most Bitcoin ATMs that exist today do not execute as quickly as Weis’s modified one did in the video, not because they don’t utilize Lightning but because they often require some form of know-your-customer (KYC) compliance that delays the process by requiring users to visit a website and provide their personal information as they would on a custodial exchange.
A Different Kind of Bitcoin ATM
A Lightning-enabled Bitcoin ATM as demonstrated by Weis could provide several key advantages over its predecessors. With the average Bitcoin ATM, customers looking to withdraw a typical amount of bitcoin will need to wait at least a few minutes before receiving it, over which the value of the withdrawn amount might fluctuate slightly.
While this may not significantly affect a customer’s purchasing power, a Lightning-enabled Bitcoin ATM offers a
