Lightning Network: The correlation between technological advancement and user experience.

2024-02-09 15:00

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Original Title: "Lightning Network: Technology and User Experience (Part 1): Basic Elements of User Experience"

Original Author: Annoy, BTCStudy

This series of articles aims to fill in some gaps in the literature on the Lightning Network. General introductions to the Lightning Network and Lightning Channels are usually written a few years ago. Therefore, they often only cover the basic technical concepts of Lightning Channels and Lightning Network, without linking the technical principles with user experience - especially the challenges in user experience. As a result, they cannot provide readers with a mental foundation for using the Lightning Network.

There is no reflection of the technological improvements and solutions that have already emerged on the Lightning Network, as well as the optimization space that can still be explored. Some solutions are proposed specifically to optimize the end-user experience and have successfully improved the user experience; while other solutions, although difficult for end-users to know, have greatly improved the payment efficiency of the Lightning Network.

The difficulty in understanding and contemplating the optimization space of the Lightning Network is partly due to insufficient understanding of its "network" characteristics.

Given this, this series of articles aims to provide a new introduction that links the user experience (especially its challenges) of the Lightning Network (wallet) with technical concepts, and based on these concepts and the "network" characteristics of the Lightning Network, introduces the technical improvements that have already occurred on the Lightning Network, as well as improvements that can still be adopted.

This article is the first in this series. Unlike typical introductions, this article will not involve the technology of constructing lightning channels or the elements of forming a lightning network (which will be covered in subsequent articles). Instead, we will first understand the user experience of the lightning network (more precisely, the experience of the self-custody mobile lightning wallet). We will start from the basic idea of the lightning network and reason out the key parts of its user experience. Later on, we will continuously explain the technical reasons behind these experiences from the perspective of "experience-technology" and present corresponding improvement opportunities.

This article does not require readers to have any understanding of the programmability of Bitcoin, but requires readers to at least understand and be able to identify the key elements of the user experience of Bitcoin - sending transactions on the Bitcoin network and getting them confirmed on the blockchain - such as addresses, transaction fees, and confirmation time.

The Idea of Lightning Network

The idea behind Lightning Network is very simple:

Assuming there is a fund that is jointly controlled by both parties, namely, it can only be spent with the unanimous consent of both parties; then, when the party A wants to use the part of the fund that belongs to them to pay the party B, no witness from anyone else is needed - only the confirmation from party B is required. Party A and party B can settle their balances and complete the fund division after a long period of time.

This is like two closely related stores writing IOUs to each other, and only transferring cash when both parties need to reconcile their accounts (such as at the end of the month or year).

The shared funds like this are called "channels".

One intuitive way to understand a channel is to imagine it as an abacus with a shaft, which has two ends and some beads on it. When one party wants to pay the other, they move some of their beads on their end to the other end.

Assuming that some people have more than one channel, they can "forward payments" for others. For example, if A and C do not have a channel, but A has a channel with B and B has a channel with C, then A can use B to pay C. For example, A gives the money to B, and B gives the money to C, just like a relay race. Payment can be completed as long as both parties of each channel confirm with each other, and no other witnesses are needed.

When many "channels" connect many nodes (users) together, these nodes form a "network", allowing one node participating in it to pay these nodes without having to connect to every other node.

This is the idea of the Lightning Network: to use one-to-one channels to achieve instant payment confirmation; to use a network composed of channels to maximize the payment capacity of a single node.

Here, we will not discuss how to securely implement "channels" and "forward payments", which will be the content of subsequent chapters. What we need to know is that the most common form of Bitcoin storage that users come into contact with is the "single signature wallet", which is a form of funds that can be spent with only one private key. Obviously, this cannot be used as a channel because its control is exclusive.

The key point is that just from this overview, we can discover several key elements in the user experience of the Lightning Network. Before using the Lightning Wallet, it is necessary to understand these elements in order to use it smoothly.

闪电网络的使用体验

translates to

Experience of using Lightning Network

Online Payment

In the Lightning Network, when you need to receive payment, you must be online. From the above reasoning, this is easy to understand: receiving payment involves changing the status of funds in the channel, and the channel is shared between you and others, so you must be online to change the status of funds together with the other party.

This is different from the user experience of Bitcoin (where anyone who knows your Bitcoin address can pay you at any time without you being online) and most payment systems (such as banks and internet electronic payment systems).

However, in the current mobile Lightning wallet, this will not cause too much perception for users: connected phones have notification systems, and the wallet's server can send notifications to you, requiring you to open the app and go online to receive payments. However, if such notifications are not processed for too long, it may result in payment refunds.

收款额度

translates to

Receiving Limit

Similarly, because payment involves channels, its collection ability is limited.

Let's take the above picture as an example. Currently, the tokens are all on Alice's side, so Alice cannot receive any more payments through this channel - because Bob has no more balance in this channel! However, at the same time, Bob's ability to receive payments through this channel is determined by all the tokens that Alice has on this channel.

This is the concept of "inbound liquidity" in the cryptocurrency industry. It is a concept that is distinct from Bitcoin and other payment systems. In other payment systems, the ability to receive payments is usually unrestricted.

This feature has caused a lot of confusion and trouble for users of the Lightning Network. When you don't have enough receiving capacity, either your payment will fail (others cannot pay you), or it will lead to the creation of a new channel (so you need to pay the transaction fee to confirm a transaction on the Bitcoin chain, and the fee at this time will be much higher than the fee you normally initiate for Lightning payments).

These issues are often more severe for novice users, which is related to the current implementation of the Lightning Network: in the current Lightning Network, only one party initiating the channel opening request injects funds into the channel (this is called "one-way funding"), but this leads to a situation where one party (such as a user) will have no receiving capacity in a newly created channel - you must spend some money before you can receive payments.

In the following chapters, we will learn how to optimize the success rate of payments. Simply put, what we need to do is to break down a payment into multiple fragments and let each fragment take a different path, thus maximizing the use of payment limits on different paths.

Conclusion

In this article, we have learned about the basic idea of the Lightning Network and, based on these basic ideas, explained some key elements of the Lightning Network user experience. These descriptions cannot cover the entire experience of independently managing Lightning wallets on mobile devices today, but they outline a part of it. In the following chapters, we will learn more and more about these experiences, as well as explain the technology or design factors behind them, and point out which technological advances have changed or are expected to change these experiences.

闪电网络是一个网络——对这个事实，再怎么强调都不过分。这种「网络」特性，既形成了其使用体验中的一些明显的特点（也许有人将它们视为一些缺点），也指明了这些体验的优化空间。

Lightning Network is a network - it cannot be emphasized enough. This "network" characteristic forms some obvious features in its user experience (which some may consider as drawbacks), and also indicates the optimization space for these experiences.

In the next chapter, we will introduce the construction method of Lightning Network on Bitcoin.