Original author: Eli Ben-Sasson
Original translation: TechFlow
Starknet will be the first network to settle on both Bitcoin and Ethereum and scale Bitcoin to thousands of transactions per second. This will be achieved within six months of Bitcoin's potential upgrade OP_CAT. This is my proposal for the future of Starknet and for blockchain, the global economy, and individual rights. We have taken concrete steps towards this vision and publicly support the adoption of OP_CAT.
It’s time for STARKs to take on the next challenge. The time has come for STARKs to demonstrate their ability to scale on Bitcoin, the most egalitarian currency in history. Once Bitcoin adopts OP_CAT, implementing STARK validators in Bitcoin script will become a reality. This opens the way for secure, self-custodial movement between Bitcoin and Starknet, creating a single-layer secondary network that scales both Ethereum and Bitcoin.
Crypto can cleanse the digital and financial world, provide integrity to money and rebalance power in society away from big tech companies and back into the hands of sovereign individuals. It is a tool to empower humanity and grassroots communities. In short, it is a source of good. Therefore, we need a vision that demonstrates this and is relevant to all. I left my quiet academic career to pursue this vision.
None of this vision can be accomplished without scaling the chain that started this great project. By scaling Bitcoin, we will unleash the power of blockchain to change the world. StarkWare is supporting this initiative with practical steps and the launch of a $1 million fund to support new research that will reveal the pros and cons of Bitcoin adopting OP_CAT.
Our strategic collaboration with Weikeng Chen of L2 Iterative Ventures (L2 IV) through the ZeroSync Foundation was extremely fruitful, culminating in the creation of the Bitcoin Wildlife Sanctuary. We leveraged his team’s hands-on engineering and research expertise to advance the open source work of OP_CAT-based conventions and STARK validators implemented in Bitcoin Script. We are also grateful to BitVM and the ZeroSync Foundation for opening many eyes to the potential of Bitcoin. Carter Feldman of QED was also influential, showing us what can be discovered with a new perspective and open-minded look at Taproot.
There will be many official updates from StarkWare and Starknet after this post, but for now, I want to get back to basics and state why we are doing what we are doing.
(Video source)
2008: Break
It was 2008 and global finance had just collapsed. In response, Satoshi Nakamoto released the revolutionary Bitcoin whitepaper. In this moment of fracture, Satoshi showed us how we could do things differently. We, the public, could demand and enforce higher standards of integrity and transparency in finance. Rather than relying on the fortresses and skyscrapers of traditional banks, Satoshi introduced an inclusive protocol that invited everyone to join. Through Bitcoin mining and fees, this protocol distributed value fairly and transparently to its broad contributor base. The broader the contributor base, the better and more secure Bitcoin will be.
Bitcoin gives us so much more than a ledger — it gives us confidence in change. It does so at a time when banks are screwing up, busy repossessing homes, and hoping we don’t realize that even with all the “trust us” confidence of mortgages, a house isn’t always “as safe as a house.”
When fully realized, Bitcoin’s impact can go beyond the reality we see today. Its destiny can and should be to be widely used as a global reserve. It can become the foundation of a global “trust network” that supports all the social functions we need for a free society: currency, property rights management, and social interaction.
The Bitcoin whitepaper foresees a network, large and small, that is actually used for payments, operated by everyone, rich or poor. Today, 1.5 billion people around the world don't even have a bank account. For these people, Bitcoin payments are not just an alternative, but their first exposure to financial infrastructure. Bitcoin today offers too little capacity, and the existing capacity is too expensive for almost all of these 1.5 billion people. I am motivated to develop technology that can make Bitcoin and the free society it supports accessible to everyone.
The elephant in the text
Some people think StarkWare is an Ethereum fanatic. While we share Ethereum’s values and are committed to its success, we are STARKs fanatics first and foremost. Starknet is deployed as a layer 2 on Ethereum, and connecting Starknet to Bitcoin is also a natural extension of its feature set. This is consistent with the vision we have firmly held since founding StarkWare, that STARKs are the public good required to scale all truly decentralized blockchain projects. Of course, Ethereum is also a manifestation of the same ambitious mission outlined earlier, although it has taken a different path with different trade-offs. This is good because overall this increases our chances of success in building a protocol that is resistant to state actors. The core values of Ethereum are why we chose it as the settlement layer for Starknet, and those values remain. We firmly believe in Ethereum and are committed to its long-term success. Bringing ZK-STARKs to Bitcoin is not a departure from our path, but a return to the starting point. To date, StarkWare has deployed all of its systems on Ethereum. But the idea of STARKs to scale blockchains was first conceived at a Bitcoin conference in the spring of 2013.
I took the stage at a conference to talk about my then-rudimentary and somewhat eccentric research on a type of cryptographic proof that would later be called STARKs, and many in the audience responded that this cryptographic research was exactly what blockchain needed. In other words, I was “orange-pilled” by Bitcoin, two years before Ethereum launched.
So, StarkWare has been deeply involved in Bitcoin since the beginning and has been watching the network with admiration. I feel comfortable having this conversation publicly now as Taproot and potentially OP_CAT are shaping what is possible for Bitcoin.
We have also supported groundbreaking Bitcoin projects like ZeroSync, which is integrating ZK proofs with Bitcoin to enhance privacy and scalability. StarkWare also commissioned researcher John Light to write the Validity Rollups on Bitcoin report, which reassessed the potential of existing validity rollups to integrate with Bitcoin and concluded that an ideal match may exist. Our next generation circular STARK prover-verifier, Stwo, works on the finite field M 31. This field works well with Bitcoin Script, making us well suited to deliver the next generation of Bitcoin extensions.
What I hope to see
My dream is to see Bitcoin reach the scale it needs to continue to work for everyone. This includes being open to everyone, without economic barriers. I think this must adhere to Satoshi's commitment to decentralization and security.
The internet started as a playground for a small group of engineers and academics. It took years to scale it, making it the infrastructure that underpins our lives. Blockchain is a tool that runs on top of the internet and can democratize the internet and rebalance power by distributing trust and integrity to sovereign individuals in a large community, rather than entrusting it to a few large companies. But to truly seize power and bring it back to the masses, it needs to scale.
I also believe that the opportunity of Bitcoin scaling should be used to advance a value that many in the Bitcoin community consider important: privacy. The same cryptography that provides Bitcoin scalability also provides the raw materials for enhanced privacy capabilities. Over time, we will see that you can own everything: your keys, your coins, your confidentiality.
How do we expect to achieve this?
We, StarkWare, are taking three concrete steps today to scale Bitcoin:
We will be proposing a new Starknet design that unifies the space by making Starknet a self-hosted decentralized layer-2 that settles on both Ethereum and Bitcoin simultaneously. A single layer that settles on both chains simultaneously. Our team will be conducting or sponsoring all the work required to make this happen. Details of the architecture we are working on will be announced in the coming weeks.
StarkWare has launched a $1 million fund that will be awarded to Bitcoin researchers and developers to study OP_CAT and its impact. These grants will be awarded to individuals and projects that conduct research in good faith, either for or against the upgrade, as well as contributors who provide proof-of-concept for OP_CAT use cases. Details on this fund will be announced next week.
Ultimately, we believe that the OP_CAT Bitcoin soft fork is the safest path to Bitcoin scaling, specifically enabling STARK verification and roll-up. Therefore, we announce our public support for OP_CAT. OP_CAT makes trustless roll-up possible on Bitcoin by enabling recursive conventions that automatically manage and update its state, thereby significantly increasing transaction throughput without overloading Bitcoin.
What can scaling Bitcoin unlock?
By scaling Bitcoin, we will be able to process transactions for millions of users in one second, up from the current rate of about thirteen transactions per second. Some of the use cases we envision for scaling Bitcoin include:
Scaling Bitcoin and Ethereum at the same time: Blockchains are fragmented today. You can choose Bitcoin, the "digital gold" that holds value but can't do much else, or Ethereum, which aims to be the "world's computer," or one of the smaller chains. By spanning and offering a choice of the two largest chains (dApps can choose one or both), Starknet will eliminate their fragmentation. It will scale both simultaneously without interfering with the independent governance of either chain.
Privacy: STARKs, cryptographic proofs used by scaling processes, have huge, as-yet-unrealized privacy potential built into them. The potential for privacy is a natural fit for the Bitcoin community. The “zero-knowledge” aspects of technology are already well understood, but still need to be unpacked and translated into practical solutions. Integrating private second layers into the Bitcoin ecosystem, leveraging technologies like Zcash, MimbleWimble or Noir, can significantly enhance transaction privacy.
Providing Financial Services to the Excluded: For us, Bitcoin’s mission has always been partly about empowering the underprivileged. Approximately 1.5 billion people worldwide lack access to traditional banking services, creating a barrier to financial upward mobility. Other attempts to scale Bitcoin have yet to provide a solution for mass use. Through new scaling methods and additional tools, Bitcoin has the potential to provide an inclusive and global financial system to the world’s unbanked.
Financial Innovation on Bitcoin: Bitcoin today enables digital cash payments, but the modern market requires more: better self-custody options with programmable vaults, risk management and hedging tools, credit, lending, derivatives, futures contracts, etc. All of these require more functionality that cannot and should not be built directly on Bitcoin. Making Starknet a second layer on Bitcoin provides the best of both worlds: huge financial innovation secured by the security of Bitcoin as digital gold.
Improved user experience: Bitcoin’s original self-custody security also makes it difficult to safely handle from the average user’s perspective. A modern second layer will provide users with a secure and simple self-custody interaction for most of their daily needs while relying on Bitcoin’s solid but cumbersome first layer security as a long-term store of value.
Why OP_CAT, STARKs, and Starknet?
Why OP_CAT? STARKs require verification of a hash chain, nothing more. Their main verification loop consists of simple algebraic operations (addition and multiplication modulo small primes) and verifying that entries pre-committed via a Merkle tree were opened correctly. OP_CAT uniquely makes it possible to create and open Merkle tree entries in Bitcoin Script, as the core operation that enables Merkle tree creation and verification is to concatenate two values and then hash them (OP_CAT enables concatenation). While other convention-enabling opcodes may be more powerful, OP_CAT is the only opcode currently under discussion that allows Merkle tree verification.
Why STARKs? In short, they offer the most scale, are the most battle-tested, the most secure, require no trusted setup "toxic waste", have no exotic cryptographic primitives, and are even post-quantum secure. The new STARK prover-verifier Stwo uses is small in number, fits into Bitcoin's stack, and is much more efficient.
Why Starknet? Starknet already has a vibrant developer community on Ethereum, and a programming language that puts the full power of scaling in their hands. Starknet’s native (and open source) Cairo language will look familiar to any developer who knows Rust. The Bitcoin community today does not have an obvious high-level language for building the world of on-chain activity. I hope Cairo can fill this gap and become one of Bitcoin’s native languages.
