Bitcoin has been hampered by its own popularity. Thanks to the way the blockchain is designed, the speed of transactions is slow and the cost of transactions has gone up.

Researchers, developers, and the Bitcoin community have been trying to come up with a way of allowing Bitcoin - and other cryptocurrencies - to accommodate more transactions. Their best efforts yet are focused around something called the Lightning Network. Can it fix the currency's scaling problems? We find out below.

Bitcoin’s current limitations

There are two limitations we need to explain when it comes to blockchain before we can explore how people are trying to fix it.

The first is speed.

In a blockchain, blocks are essentially groups of transactions collected together. As part of a blockchain’s design, there are only so many transactions that can be included in a block.

If your transaction doesn’t make it into the current block, it joins a queue. That queue can take anywhere from a few minutes to a day to process.

That limits the blockchain’s use as a medium to process quick transactions, like buying a cup of coffee. No one wants to wait around for the network to verify you’ve got the cash.

Bitcoin limitations: cost

Bitcoin’s network - and others - is built upon a consensus protocol called proof-of-work.

This is where miners expend energy trying to solve a difficult puzzle. To help offset the cost of equipment and energy used in that calculation, miners charge transaction fees.

When the system is small, and the amount of transactions needing verifying are few and far between, the network works well and transaction costs are low. As the network grows however, so does the cost of transaction fees.

At its peak in 2017, to process one transaction on Bitcoin - whether it was for $1 or $1000 - was $28. That makes Bitcoin un-economical as a form of currency. That’s where the Lightning Network comes in.

We've got a whole article explaining more about Bitcoin's limitations.

What is the Lightning Network?

The Lightning Network is a system of channels allowing people or companies to move money between each other without needing to use the blockchain to verify the transaction.

In theory, it could allow thousands or even hundreds of thousands of transactions to take place instantly, making it great for small transactions.

It bears resemblance to the current settlement system used by companies like Visa and Mastercard. When you pay for something it’s not instantly settled.

Instead, there’s a quick verification of funds from the buyer and the request from the seller - giving the green light for a transaction to take place.

The settlement of the funds happens later, in some cases days or weeks later.

Did you know?

Jack Dorsey, the CEO of Twitter is a big fan of the Ligthning Network and has personally invested in the project!

Who came up with the idea?

The idea was first proposed by Thaddeus Dryja and Joseph Poon, the founders of the Lightning Network, in a 2015 white paper.

The idea was to create a settlement layer on top of the blockchain, freeing up the core network from processing individual transactions.

How does the Lightning Network work?

Let’s say you want to transact with your local coffee shop. First, you’d need to send some Bitcoin to a wallet that requires more than one signature or key to release the funds.

These are commonly referred to as multisig wallets. These multisig wallets require more than one signature in order to release funds. In the case of the Lightning Network it allows to people to enter into an agreement. In effect, creating a balance sheet.

Every time you buy a cup of coffee you create a new balance sheet and sign it with your public key to reflect what’s left in your wallet, and what’s in your coffee shop’s wallet.

If you don’t want to buy coffee anymore from that coffee shop, you can close the channel, and the resulting balance sheet is committed to the blockchain as a permanent record.

Payment disputes can also be settled by referring to the last signed balance sheet between the two parties.

What happens if you don’t have a direct channel with the next place you want to buy something from? The network will find the shortest route between you and the shop via others in the network.

Not just for Bitcoin

Although it was originally designed for Bitcoin, the technology is currently being developed for a range of cryptocurrencies which include Litecoin, Stellar, Ether and Ripple.

When will we see it in action?

It’s already live! A version was launched on Bitcoin in March 2018, and has started popping up in different places. One of the most recent is Twitter!

The future

The popularity of cryptocurrencies and transacting on them has, within just a few short years, put increasing stress on the blockchains they’re built on.

While there have been smaller changes - and some cases forks - to help the networks get quicker, the Lightning Network, if successful could help open the door to widespread adoption of cryptocurrencies and their applications.