OKX Blockchain 60 Lectures | Episode 25: What is the Lightning Network?

Hello everyone, I'm Xiao K. Today we're going to talk about: "What is the Lightning Network"?

The Lightning Network is a technology first proposed in 2015 by Joseph Poon and Thaddeus Dryja in a whitepaper to solve Bitcoin trading congestion.

This technology originated from a problem left over from Bitcoin's early days. Because when Bitcoin was originally designed, each block was only 1MB in size, which could only record a few thousand transactions. But as Bitcoin gained more popularity and more people started using it, trading volume increased significantly, and this capacity clearly became insufficient, leading to Bitcoin's trading congestion problem. To solve this issue, the Bitcoin community proposed two solutions: one was to expand Bitcoin's block size, and the other was to not expand the capacity. The Lightning Network falls into the latter category.

The Lightning Network's approach is to build an additional sidechain layer on top of Bitcoin's blockchain, enabling users to establish payment channels with each other on this additional layer. A portion of transactions are then processed through these channels, helping to offload transactions from the main chain.

Here's how it works: for example, if we want to make a transaction, we can establish an off-chain payment channel between us. We both place our funds into the wallet address of this channel first. This wallet can only be opened with confirmation from both of our private keys, and it serves as a record of our assets.

After that, we can conduct unlimited transactions with each other. Each transaction is recorded in this ledger through a smart contract-like function, essentially representing a reallocation of the funds stored in our shared wallet. Whenever we no longer need to transact with each other, we can close this payment channel and submit the final result of the fund allocation caused by our series of transactions to the main chain. After being broadcast to the entire network, it will be recorded on-chain.

This approach is essentially like building a sidechain for Bitcoin. The main chain only needs to record the final allocation result, while the intermediate transactions are processed through the Lightning Network, thereby分担了主链交易的压力，自然就解决了主链交易拥堵的问题. Additionally, since all transactions within the channel are off-chain and only executed by smart contracts without requiring full network confirmation, this greatly improves the processing efficiency of transactions between users.

Furthermore, the Lightning Network can also achieve cross-chain functionality, using the hash locking technology mentioned in our previous lesson. Both chains involved in the cross-chain operation need to support the Lightning Network. Both chains deposit their assets temporarily into a temporary account in the channel, and then lock both parties' assets using hash locking technology.

For example, if A wants to exchange with B, the protocol will first lock A's funds, and then ask B to provide a secret. If the hash value of the secret provided by B equals the agreed value, the funds will be unlocked to B; otherwise, the funds will be unlocked back to A in their original form. This enables assets on different chains to be settled simultaneously during exchange, thereby completing cross-chain value transfer.

In summary, the Lightning Network is currently the mainstream solution for solving scalability and interoperability problems. It is not only applicable to Bitcoin but also to other projects. It is believed that as the Lightning Network is gradually implemented, it will allow us to truly enjoy blockchain-level security and convenience in the future.

Thanks to Instructor Shentu Qingchun for his assistance and guidance on the content of this episode.

Sina Weibo: @申屠青春

"OKX Blockchain 60 Lectures" is a blockchain educational animation video jointly produced by OKX and Sina Technology. Aimed at users with zero foundation in blockchain, it uses series articles, educational animations, and other formats to vividly explain blockchain concepts from the perspectives of concepts, technology, and applications through 5 major sections and 60 knowledge points. The content of this episode was guided and completed by Instructor Shentu Qingchun, CEO of Yinxu Technology.

Disclaimer

This article may contain product content that does not apply to your region. This article is committed to providing general information only and does not accept responsibility for any factual errors or omissions. This article represents the author's personal views only and does not represent OKX's views. This article is not intended to provide any advice, including but not limited to: (i) investment advice or investment recommendations; (ii) offers or solicitations to buy, sell, or hold digital assets; or (iii) financial, accounting, legal, or tax advice. Holdings of digital assets (including stablecoins) involve high risk and may fluctuate significantly, or even become worthless. You should carefully consider whether trading or holding digital assets is suitable for you based on your financial situation. For questions about your specific circumstances, please consult your legal/tax/investment professionals. The information contained in this article (including market data and statistics, if any) is for general reference purposes only. Although we have taken all reasonable precautions in preparing this data and these charts, we do not accept any responsibility for factual errors or omissions expressed herein. © 2025 OKX. This article may be reproduced or distributed in its entirety or used in excerpts of 100 words or less, provided that such use is non-commercial. Any reproduction or distribution of the full article must prominently state: "This article is copyrighted © 2025 OKX, used with permission." Permitted excerpts must cite the article name and include the source, for example, "Article name, [author name (if applicable)], © 2025 OKX." Some content may have been generated or assisted by artificial intelligence (AI) tools. Derivative works or other uses of this article are not permitted.

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