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Bitcoin Scaling Solution of the Week: Sidechains

Sidechains have become a popular scaling solution for blockchains. Trust Machines breaks down how sidechains work with the Bitcoin blockchain.
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Sidechains Scaling Solution for the Bitcoin Blockchain
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Happy Wednesday, and apologies for the delay on our "Bitcoin Scaling Solution of the Week" series. You may have noticed that we were all hands on deck to launch Leather, a new Bitcoin wallet brand that helps crypto users tap into the Bitcoin Web3 economy. 

But now, we're back to our regularly scheduled programming across the Trust Machines site and our products. 

Scalability is an ongoing challenge in the rapidly evolving world of blockchain technology. Developers and builders in the space are constantly working to resolve this crucial issue and to create solutions that help blockchain ecosystems grow. Bitcoin is no exception, which leads us to this week's spotlight: sidechains. 

You may remember that in our last installment of our weekly series, we explored Layer 2 solutions (L2s). L2s are often confused with sidechains, but it's worth noting that sidechains and L2s have unique traits and mechanisms that distinguish them from one another. 

What are Sidechains?

A sidechain is a separate, independent blockchain that connects to a main chain. By facilitating transactions, smart contracts and asset transfers separate from the main chain, this parallel structure provides an avenue for enhanced scalability, including the development of dApps and a reduction of network congestion. Given that sidechains are separate cryptocurrency blockchains from a main chain, they also often implement their own consensus and governance protocols.

Assets on the sidechain are backed by equivalent amounts on the parent blockchain thanks to a two-way bridge between the sidechain and main chain, allowing seamless asset transfers between both. However, this bridge offers the potential to enable interoperability between different blockchains and networks in addition to facilitating asset transfers.

L2s vs. Sidechains: A Comparative Analysis of Scaling Dynamics

While sidechains and Layer 2 solutions often intersect, they are still distinctly different concepts. 

What makes an L2, an L2?

A Layer 2 (L2), refers to a secondary framework built on top of Layer 1 blockchains that enhances transaction processing capacity and efficiency. It achieves this while retaining L1 security and decentralization properties by executing transactions on top of L1 networks like the main Bitcoin blockchain and Ethereum mainnet. 

Given this, while Layer 2s function separately from Layer 1s, they still settle back on the main chain and therefore retain an L1's security properties. State change and transaction data are also posted back to the main chain.

What about sidechains?

As we mentioned, a sidechain is a separate blockchain with its own rules, security, and consensus mechanism. Through a two-way bridge, it maintains a connection to the parent blockchain or mainnet while operating independently. The exchange of digital assets between the main blockchain and the sidechain is made simpler through this peg.

The assets are locked on one chain, and when a smart contract confirms them, an equivalent amount is unlocked on the other chain. This architecture separates a sidechain from the main blockchain by allowing experimentation, scaling solutions and cross-chain communication. However, because a sidechain is independent from a parent blockchain, it does not post state changes and transaction data back to that main chain.

L2s vs. sidechains: Understanding the differences and the similarities

To summarize, here are the main similarities between sidechains and L2s: 

  • Both aim to increase transaction throughput and blockchain scalability.
  • To increase efficiency and decrease congestion, they process transactions independently of the main blockchain.
  • Both present possibilities for testing out different economic models and transactional architectures.

But there are also key differences between the two: 

  • L2s work "on top of" the main blockchain, whereas sidechains are entirely separate blockchain networks
  • L2s rely on the security of the main chain (Layer 1) while sidechains have their own distinct security model
  • L2 solutions benefit from the security of L1s while sidechains handle their security independently

Examples of Bitcoin Sidechains

Two key examples of Bitcoin sidechains are RSK (Rootstock) and Liquid.

RSK (Rootstock) is a smart contracts platform secured by Bitcoin that enables Ethereum-like features on the Bitcoin blockchain. RSK functions as a sidechain and establishes a two-way bridge with Bitcoin. The "Powpeg" protocol and combined mining allow RSK to make Bitcoin transfers via RBTC possible. Lending, borrowing, and decentralized exchange features are offered by well-known projects like Sovryn and RSK Swap. Beyond Ethereum, RSK's combination of Bitcoin's stability and Ethereum's functionality opens up new possibilities for dApps and DeFi.

Unveiled by Blockstream in 2018, the Liquid Network is a L2 sidechain that enhances Bitcoin's capabilities. It uses its own ledger and consensus mechanism to conduct quick, secure, and private transactions. Faster asset issuance and transaction speeds increase Bitcoin's scalability, enabling cutting-edge use cases like DeFi and private transactions. BTC transfers become easier via Liquid's two-way peg mechanism, which leads to the creation of Liquid Bitcoin (L-BTC), a native asset on the Liquid Network designed to represent and mirror the value of Bitcoin (BTC). This sidechain offers effective solutions, enhanced transaction throughput, and asset issuance, all of which support Bitcoin's growth and scalability.

Empowering Bitcoin's Future: Unleashing the Potential of Sidechains for Scalability

The use of sidechains to enhance Bitcoin scalability has grown in recent years. Not only do sidechains address scalability issues, they also give developers an exciting environment to explore and build within the vast Bitcoin ecosystem. Sidechains create a strong basis for developers to achieve their objectives while enriching the entire blockchain landscape by seamlessly enabling experimentation and enhancing interoperability.

That concludes this week's "Bitcoin Scaling Solution of the Week." Next week's post will delve into an emerging technology that has been gaining traction in the Bitcoin community: rollups.