In November 2015, Bitcoin was worth some $450. The vast majority of nowadays problems related to the world of cryptocurrencies remained either totally unknown and unpredictable or had been a province of few cryptographic geeks. By the way, it was blockchain developer Joseph Poon and Thadeus Dryja, Ph.D. in cryptographic primitives and network security at the University of Virginia who (i) prominently spelled out the main alarming limitations of the Bitcoin network in commercial and technical regards and (ii) suggested the solution for these issues is to be found off-chain and only off-chain.
In fact, they contributed to the discussion that would later be called an ‘ideological battle over Bitcoin’s future’ – the Bitcoin scalability problem debate. While the understanding of both realized and proposed ways of this problem’s solution requires a high-degree knowledge in applied maths and coding, the problem itself can be described in a nutshell.
Initially, one block size in the Bitcoin network is limited to 1 MB. As the quantity and amount of transactions grow, it is not enough anymore. Confirmations time-outs are getting longer, while the transaction fees are getting higher. It results in the loss of commercial attractiveness of Bitcoin solutions since no one prefers to pay more and wait more. The situation has to be resolved as it is about the future of both the applied and theoretical dimensions of blockchain.
Obvious Problems, Controversial Solutions
On the face of it, there are two mainstream ways to solve the Bitcoin scalability problem. Adepts of first way proceed from the understanding that the block size is the only limitation to the transaction throughput. So, they say, this limit is to be increased if not removed once and for all. During the years 2015, 2016 and 2017, a series of solutions of this kind was proposed by the Bitcoin developers community. Among the successful are Bitcoin hard-forks, namely Bitcoin XT, Bitcoin Classic, Bitcoin Unlimited and the most popular and viable, Bitcoin Cash. In accordance with their rules, the block size was expended, at first, to 2 MB. Now, the last Bitcoin Cash core update released on May 15, 2018, allows to enlarge the block size up to 32 MB. This process itself generating controversy and anxiety in the world crypto society was followed by the cascade of partially successful ‘agreements’ (Hong Kong, New York etc.) through which the fractions in Bitcoin community tried to implement a new consensus on mining, thus allowing to enlarge the block size to 2 MB.
The very popular Segregated Witness or SegWit solution is a Bitcoin soft-fork, allowing to increase the block size in another way. It splits the transaction into two segments, removing the unlocking signature (“witness” data) from the original portion and appending it as a separate structure at the end. After that, the block (‘on-chain’) size is increased as signatures are ‘expelled’ from the blockchain. Since the volume of signatures is some half of the full transaction volume, the limit for the block size with the SegWit is around 1.8 MB. SegWit also addresses the issues with malleability. Signatures are impossible to change after being moved out of the transaction data. Marked as a ‘clever hack’ by the Bitcoin Magazine, the SegWit is now among the most popular Bitcoin scalability solutions. Activated on August 24, 2017, with the Bitcoin block number 481 824, SegWit reached the 10 per cent market penetration in two months. Now every 2 of 5 Bitcoin transactions are handled via SegWit. And that is really a lot.
SegWit Transactions Percentage in the Bitcoin Network. Impressive, isn’t it?
Adherents of the second way suppose that the increase of the volume of the block is only a poor remedy for the Bitcoin network scalability problem. According to them, the pivotal problem is blockchain overload, so, the transactions should be conducted without the use of blockchain as it was generally accepted up to nowadays. They observed that some transactions can be handled ‘above’ the blockchain, or, if you will, on the second layer. So, the proponents of this approach stuck to the ‘Second Layer’ solutions.
Unloading The Blockchain
The Lightning Network ideologists Ј. Poon and T. Dryja asked in their whitepaper: “If a tree falls in the forest and no one is around to hear it, does it make a sound?” They compared the transaction between our familiar Alice and Bob to a tree in the forest. “…if only two participants care about an everyday recurring transaction, it’s not necessary for all other nodes in the Bitcoin network to know about that transaction. It is instead preferable to only have the bare minimum of information on the blockchain”, they declared.
There’s a plenty of Lightning Network schemes in the Internet, I had a hard time finding a clear one for you. Have a look: only two peers know the full information about the transaction with only critical data saved in the blockchain.
To put it at its plainest, in the Lightning Network, if Alice and Bob come to the agreement that the tree fell down at 2:45 PM, it is true without regard to public opinion. Their agreement that before the transaction Alice had 0.5 BTC and Bob had 0.4 ВТС, then after the transaction, Alice owned 0.6 BTC and Bob should content himself with 0.3 BTC, is secured by the hash-time lock contract. This transaction is atomic: it is to be finished only in case of bilateral recognition. Thus, there is no way for fraudulent payments: if the transaction is not broadcast within the timeframe defined in the contract, then it is considered null and void. The channel the transaction is sent through is live only for the time of the swap.
From The Idea to Mainnet: Lightning Solutions Development
Unlike the Rayden second-scale solution for the Ethereum ecosystem, which is solely developed by Brainbot Labs, there is a couple of teams working on Lightning Network in parallel. Moreover, the commercial and non-commercial implementations of Lightning are being developed separately. Non-commercial implementation of Lightning is researched by Digital Currency Initiative of MIT Media Lab (project LIT). Commercial implementations are being developed by Blockstream (project Lightning Charge, see the wide range of specifications proposed by Rusty Russel, one of the most well-known Lightning contributors), Lightning Labs (project lnd) and ACINQ (project Éclair). Now, every abovementioned team presented the beta version for the developers and those who would like to test its features with a dummy amount of coins. The up-to-date condition of the Lightning Network connections worldwide can be found here. At the time of publication, it consists of 2699 nodes and 7403 channels with a total capacity of $0.6M.
Lightning Network Channels Live.
It’s no great deal at the time, but it is increasing day by day.
Why does it matter? There are four main spheres of use the Lightning solutions can be implemented in. Firstly, it is the huge sphere of instant payments. With its prompt speed of operation, Lightning Network can bring the Bitcoin close to the b2c-payments, replacing Visa and MasterCard. Then, it is the trading (or exchange) arbitrage. There is presently an incentive to hold funds on exchanges to be ready for large market moves due to 3-6 block confirmation times. It is possible for the exchange to participate in this network and for clients to move their funds on and off the exchange for orders nearly instantly. Micropayments, e.g. machine-to-machine payments in amount of some Satoshis are also waiting for a solution of that kind. Finally, it can open new levels for applied financial smart contracts and escrow as the third parties are totally expelled from the chain.
Swap.Online x Lightning Network: Long Drive Ahead
Swap.Online, as an OTC crypto marketplace, has a lot of common grounds with Lightning Network solutions. First and foremost, it is due to our special interest in the swaps with Bitcoin. It seems to be really appreciated by the market, since the most popular and advanced modern decentralized exchanges support only ERC-20 tokens. We decided to emphasize the possibility of Bitcoin atomic swaps, since it remains the most popular and attainable cryptocurrency. Then, the Lightning Network focus on the machine-to-machine payments and micropayments in common is coincidental with our b2b-product – Swap Button, the tool for receiving the investments in crypto. Finally, big and experienced traders are obviously interested in high-technology, as instant swaps will eventually switch to the Lightning Network. As a result, we have a strong interest in the research of Lightning algorithms.