WHAT IS BITCOIN’S LIGHTNING NETWORK?
Tackling bitcoin’s scalability isn’t easy, but developers Thaddeus Dryja and Joseph Poon had an idea. In a 2016 white paper, they proposed the concept of a protocol called “the lightning network” that would enable faster and cheaper transactions while not having to change the block size.
The network creates a second layer on top of the bitcoin blockchain and comprises user-generated channels. You can securely send payments back and forth without the need to trust or even know your counterparty.
Say, for instance, that I wanted to pay you for each minute of video that I watched. We would open up a lightning channel, and as the minutes rolled by, periodic payments would be made from my wallet to yours. When I’m done watching, we would close the channel to settle the net amount on the bitcoin blockchain.
Because the transactions are just between me and you and don’t need to be broadcast to the whole network, they are almost instantaneous. And because there are no miners that need incentivizing, transaction fees are low or even non-existent.
How it works
First, two parties who wish to transact with each other set up a multisignature wallet (which requires more than one signature to enact a transaction). This wallet holds some amount of bitcoin. The wallet address is then saved to the bitcoin blockchain. This sets up the payment channel.
The two parties can now conduct an unlimited number of transactions without ever touching the information stored on the blockchain. With each transaction, both parties sign an updated balance sheet to always reflect how much of the bitcoin stored in the wallet belongs to each.
Once the two parties finish transacting and close out the channel, the resulting balance is registered on the blockchain. In the event of a dispute, both parties can use the most recently signed balance sheet to recover their share of the wallet.
It is not necessary to set up a direct channel to transact on lightning – you can send payments to someone via channels with people that you are connected with. The network automatically finds the shortest route.
Development of the technology got a significant boost with the adoption of SegWit on the bitcoin and litecoin networks. Without the upgrade’s transaction malleability fix, transactions on the lightning network would have been too risky to be practical.
Without the security of the blockchain behind it, the lightning network will not be as secure, which implies that it will largely be used for small or even micro transactions which carry a lower risk. Larger transfers that require decentralized security are more likely to be done on the original layer.
Where are we now?
In March 2018, California startup Lightning Labs announced the launch of a beta version of its software, making available what investors and project leads say is the first thoroughly tested version of the tech to date. It is still early days, however – transaction sizes are limited, and the release is aimed at developers and “advanced users”.
Recent research on the lightning network shows signs of increased vulnerability due to the centralization of a number of nodes in the network that control a majority of funds. Developers are continuously exploring new possibilities to enhance the privacy and efficiency of the lightning, as well as ways to incorporate other technologies such as Schnorr into the network. There’s no doubt that it’ll be some time before such system-wide updates can successfully take place.