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Build to Last. Build on Rootstock.

By CEO of RootstockLabs Daniel Fogg

Build to Last. Build on Rootstock.

This is part of a series called “Build to Last” that answers questions that are central to our work at RootstockLabs.

I have tried to write short-form, low-tech explanations of what can sometimes be complicated, highly technical concepts. Links for further reading are provided when possible.

In this first part, I explain why Rootstock exists, what a Bitcoin sidechain is, I lay out the reasons for building on Rootstock, and how Rootstock compares to other blockchain networks.

Why does Rootstock exist?

Rootstock was built by a group of Argentinian engineers and entrepreneurs who wanted to solve the real-world problems they experienced from an economy that was failing them. They had a vision for a new economy and designed Rootstock as the technological foundation.

This new economy should be open in every sense. Open for builders to create innovative protocols, open for investors to put capital to work, and open for people to use everyday. This new economy must be built on the most robust, most secure technological foundations that exist.

In 2015, the Bitcoin blockchain had already established itself as a new way to make peer-to-peer payments, and Bitcoin as an asset had the potential to be the first mainstream form of digital money. But a functioning new economy requires much more than money and payments.

At around the same time, Ethereum was launched to address the limitations of Bitcoin by introducing the ability to program smart contracts and tokenise assets. This mattered, because Ethereum now provided the ability for developers to build out the rest of the new economy.

We believe that elements of both Bitcoin and Ethereum are necessary to build a new economy. Neither one on its own is enough.

So we combined Bitcoin and Ethereum, and created Rootstock – the first Bitcoin Sidechain. Rootstock brings together the benefits of Bitcoin (security, store of value, widespread adoption, and decentralisation) with the benefits of Ethereum (smart contracts, programmability, token utility). This combination makes Rootstock the most secure smart-contract platform on the planet.

The best of both worlds. A smart-contract platform that can withstand almost anything thrown at it. An impenetrable, uncensorable, unstoppable machine at the heart of a new economy.

Today, the Rootstock blockchain is maintained, upgraded, and supported by hundreds of committed engineers and builders around the world. For many of them, getting access to US Dollars, protecting assets from inflation, and securing savings from bad actors is not an abstract philosophical problem, it is an everyday reality.

This is why Rootstock exists. To act as the best foundation for a new economy. Designed by, and built for, people who need this new economy to exist.

What is a Bitcoin Sidechain?

Bitcoin sidechain is a blockchain that is secured by the Bitcoin blockchain and uses Bitcoin as a store of value. In the case of Rootstock, it also financially supports the Bitcoin miners, and therefore contributes to the future survival of the Bitcoin blockchain. Extending the functionality of Bitcoin through a sidechain like Rootstock also future-proofs Bitcoin’s foundations as the world’s largest cryptocurrency by market cap.

While the Bitcoin sidechain concept dates back to the very early days of Bitcoin, for a long time Bitcoin sidechains remained only theoretical. That is until the Rootstock (then RSK) whitepaper was published, and eventually launched in January 2018.

So what makes Rootstock – as the first Bitcoin sidechain – unique from other blockchains?

  • Bitcoin blockchain enables the consensus of Rootstock through the merged-mining process + DECOR. The majority of Bitcoin miners mine Rootstock blocks.
  • Bitcoin is the native token. No other money token is needed to pay gas for compute. Rootstock has no money token that competes with Bitcoin as a store of value.
  • Bitcoin miners earn by merged-mining with Rootstock. This makes Rootstock and the Bitcoin miners economically aligned. They support each other.

Why build on Rootstock?

Developers and innovators should be focussed on one thing: the best route to achieving their product or business goals.

So – why build on Rootstock?

  • Build on Bitcoin: Rootstock was the first Bitcoin sidechain. If you build on Rootstock, you are cryptographically, economically, and philosophically building on Bitcoin. Your project benefits from the security of the Bitcoin blockchain and the store-of-value of the Bitcoin token. Rootstock was built to last.
  • Build on Ethereum, Fork to Rootstock: Rootstock is an EVM-compatible blockchain, so all tokens and all protocols that work on Ethereum, can also run on Rootstock. So switching to Rootstock is fast and easy.
  • Build for Rootstock: As an EVM, you can write smart-contracts for Rootstock in Solidity. There are loads of resources on how to write Solidity. This means developer knowledge ramp-up time from Ethereum to Rootstock is very low.
  • Build within an Ecosystem: A large, and rapidly developing ecosystem of developersprojects, enterprises, and governments have built on Rootstock. From Bitcoin-backed stablecoins (Dollar on Chain), to Bitcoin DeFi platforms (Sovryn), to everyday investment services (Buenbit), to government identity systems (Gibraltar) – the Rootstock ecosystem is diverse, experienced, and committed. There are hundreds of partners and protocols live on Rootstock, and Rootstock tokens are now supported by some of the largest exchanges (like Binance) and largest wallets (like ExodusFrontierMy Ether WalletLedger Live) in the world.
  • Build with capital support: DeFi protocols often need capital support and liquidity during the delicate bootstrapping phase. Rootstock has a number of active liquidity partners in the ecosystem, such as the Systema Fund which has thousands of Bitcoins to deploy specifically to support projects on Rootstock which offer competitive returns.
  • Build with Purpose: Speed, security, and money are of course not the only motivators for human endeavour. Humans value purpose. Ideas that give their life meaning, and that are larger than ourselves. Rootstock was designed by, and built for, the underbanked of the world. This purpose informed many of the technological choices in Rootstock’s original design. It motivates many Rootstock contributors today. And this is a purpose developers who build on Rootstock can connect to, and contribute to. It is still early. There is much work to do.

Why is Rootstock the best layer-1 protocol?

We believe that Rootstock is the best layer-1 protocol. This belief is supported by the cryptographic security of the network, the economic and technical alignment to the Bitcoin blockchain, and the blockchain performance in speed, cost, and interoperability.

So when builders are thinking about building on Rootstock, here are some important, functional benefits to consider.

  • Secure: Rootstock is merge-mined using Bitcoin Proof-of-Work (PoW). That means Rootstock is secured using the Bitcoin blockchain. At around 57%+ of Bitcoin Blockchain hash rate, that means 57%+ of all the Bitcoin blockchain cryptographic computing power is also securing Rootstock. Wild, but true! Conceptually simple, a widely-respected approach, and resilient against a range of attacks.
  • Bitcoin-native: The native token of Rootstock is Bitcoin. To bring Bitcoin into Rootstock, you lock BTC in a smart-contract called the Proof-of-Work Peg, and unlock RBTC. You don’t need any other token to pay for gas. And there is no token wrapping required. On Rootstock, Bitcoin is king.
  • Fast: Rootstock has the fastest block confirmation time (30 seconds, on average) among all Bitcoin Sidechains and Bitcoin Layer-2s, while also placing no limit on the value of a transaction.
  • Affordable: Rootstock transaction fees, at around $0.03 on average today (September-2023), are some of the lowest among comparative blockchains, are lower than other Bitcoin sidechains, and are much lower than Bitcoin blockchain transactions.
  • Interoperable: Rootstock is the only Bitcoin layer-2 that is EVM-compatible. This means developers can create smart contracts using the Solidity programming language, as well as launch and bridge Ethereum-native ERC-20 (most crypto assets) and ERC-721 (most NFTs) tokens on Rootstock. This makes the majority of smart-contracts, protocols, and tokens easily interoperable with Rootstock.
  • Unlimited: Up to 21 million Bitcoin can be locked in the Proof-of-Work Peg, and an unlimited amount of cryptocurrency value can be launched or bridged into Rootstock. That means every Bitcoin that could ever exist, can be used in Rootstock.
  • Up-time: Rootstock has been up-and-running for 100% of the time since it was first launched in January 2018. Funds in the Proof-of-Work Peg have never been stolen. The network has never gone down. 5-years, and going strong.
  • Confidence: Over $100M of BTC is locked on Rootstock today (September-2023), and an additional $197M of other tokens have been minted on Rootstock or brought through the Ethereum Bridge to Rootstock.


For all these reasons, we believe that if you want to build a new economy, you must build to last, and the best choice is to build on Rootstock.