Alice: We're very excited to have you, Rob.

Rob: It's my pleasure. Thanks for having me.

Alice: Of course. Let's start off with a brief introduction of yourself. How did you get involved in the web3 space, and what led you to focus specifically on ZK?

Rob: Absolutely. The ZK part comes from my broader interest in this space. Initially, I was a physicist and mathematician. I worked with the U.S. Air Force, what’s now known as the Space Force, on satellite, radar, and rocket systems. Later, I transitioned into intelligence operations, but I always had this philosophical fascination with Bitcoin - the idea of separating money from the state really resonated with me.

I was fortunate to see the potential early on, and Bitcoin’s concept of programmatic money made a lot of sense to me. While I don’t exactly think of it as opting out, it felt like an opportunity to create an alternative financial system, one that would benefit places with poor governance - places like Afghanistan, where I worked for a time. It inspired me to make a career change; I left my previous work to pursue a Ph.D. in crypto finance around 2014. Eventually, I co-founded Zencash in 2017, which evolved into Horizon. My journey into ZK began there, trying to improve on the privacy technology that Zcash brought to market. Since then, we've expanded Horizon and started Horizon Labs to keep innovating.

Alice: That's a fascinating journey, starting with the philosophical aspect. It seems like your motivation has always been about the bigger picture and impact.

Rob: Absolutely. That motivation still drives me today. My team and I were just talking about this during an offsite this week - why are we doing what we’re doing? Are we just here for incremental gains, or are we solving a bigger problem? And for us, it always comes back to that core vision of making a meaningful impact.

Alice: You mentioned your experiments with ZK over the years - from privacy coins to launching ZKVerify and now Horizon 2. What's your long-term vision for ZK technology? How do you see it evolving in the next 5, 10, or even 20 years?

Rob: Predicting the future is always tough, especially in this space, but I do have some thoughts. The boldest prediction I’ve heard, and one that I believe in, comes from Vish Rauf, a well-known cryptographer. She has said that ZK might eventually replace blockchain. If we can create succinct proofs of everything, we might not need to have blockchains as we know them today. We wouldn’t need to order transactions through consensus in the traditional way - we could just rely on proofs.

In the near term, I think ZK will become much more usable. Every part of the ZK value chain is being optimized right now, from proof generation to verification. We’re working on ZKVerify to streamline the verification process, and I think as these pieces mature, the applications will become far more interesting and accessible.

Alice: That's exciting to think about. Personally, I'm interested in how ZK proofs could be used for general computation, not just on-chain but for off-chain applications too. Do you see that playing an important role?

Rob: Absolutely. ZK proofs for general computation are going to be a key area, though we’re still in the early days of seeing applications scale. But I think that’s where things are heading, and it’s definitely something we’re considering as we develop our technology.

Alice: Let’s talk more specifically about privacy. How do you see privacy in today’s world, and what role do you think ZK plays in improving privacy?

Rob: Privacy is under attack globally, and it’s not given the respect it deserves. The traditional financial system is designed for surveillance - and it's effective for its goals, but it comes at the cost of personal privacy. Originally, many people thought Bitcoin was private, but we learned that it’s only pseudonymous. As a community, we’ve since developed privacy tools like mixers, Zcash, and zk-SNARKs, but adoption has been slow.

For example, Zcash, which provides robust privacy, still doesn’t have the same level of adoption as Bitcoin. That raises the question: do people value privacy enough to demand it? I think privacy still has a major role to play, especially as more of our financial lives move on-chain. We’re working on privacy-focused tools at Horizon Labs, and we believe ZK can provide a foundation for privacy-preserving digital identity systems - something that’s crucial for broader adoption.

Alice: What are the main barriers to adoption for privacy-focused technologies, and how is Horizon Labs addressing them?

Rob: There are several barriers. First is trust - many people trust traditional institutions more than decentralized projects. Then there's regulatory risk; projects can get shut down arbitrarily, which creates uncertainty. Lastly, there's usability. Historically, our industry hasn’t built user-friendly products, but that’s improving. At Horizon Labs, we're focusing on improving the user experience, and we’re building tools like ZKVerify to make ZK adoption easier and more cost-effective.

Alice: Speaking of ZKVerify, could you explain what you're building at Horizon Labs, specifically with Horizon 2 and ZKVerify? What sets you apart from other players in the space?

Rob: Horizon Labs is building three main things right now: Horizon 2.0, ZKVerify, and we’re also working with Offchain Labs to deploy ApeChain. Horizon 2.0 is an evolution of our original blockchain. It’s an EVM-compatible environment designed specifically for ZK apps, with precompiles for different elliptic curves to make proof verification faster and cheaper.

ZKVerify, on the other hand, is a universal proof verification layer that can take any ZK proof and verify it efficiently. The idea is to make verification dirt cheap and fast, no matter where the proof originates. We’re also integrating ZKVerify with ApeChain, a new gaming platform we’re developing with Offchain Labs, to provide in-game privacy features.

Alice: That's very innovative. You mentioned built-in precompiles for proof verification - what's the advantage of using these versus custom contracts?

Rob: Precompiles are shortcuts that make verification cheaper and faster. In Horizon, we’re able to execute these verifications in milliseconds without the gas costs that you’d face on Ethereum. Our framework is built using Substrate, allowing us to add new precompiles via forkless upgrades, meaning we can stay on the cutting edge without the complexities of hard forks.

Alice: With ZKVerify, you’re essentially outsourcing proof verification for rollups. What’s the advantage of that, and what trade-offs come with outsourcing this verification?

Rob: Outsourcing proof verification means cost savings, but it introduces some trade-offs. When you verify on Ethereum, you inherit Ethereum’s cryptoeconomic security guarantees. When you verify through ZKVerify, you rely on our network and a bridge to relay the result to Ethereum, which introduces additional risk. However, the cost savings can be significant. We think of it as a spectrum - for some applications, the cost savings are worth the trade-off, while others may prefer Ethereum’s security. We also offer the option of periodic checkpointing to Ethereum to maintain a balance between cost and security.

Alice: That's an important point. Not every use case requires the highest level of security, and providing choice is crucial for developers.

Rob: Exactly. We want to give developers the flexibility to make those decisions based on their own needs.

Alice: Before we wrap up, how can those interested get involved with Horizon Labs?

Rob: If you’re a developer interested in building privacy-focused or ZK applications, we’d love to work with you. We have grant programs for both Horizon and ZKVerify, so you can get support for your projects. We’re also looking for community members who are passionate about privacy. You can join us on Discord, Telegram, or reach out on social media - we’re always here to collaborate.

Alice: Great, thanks so much, Rob. Your insights today on privacy, verification, and Horizon’s role in the ZK space have been invaluable. Thanks again for joining.

Rob: Thank you, Alice. It’s been great discussing ZK technology with you. We need more of these conversations, so keep it up!

Alice: Absolutely. Thanks, Rob.Follow @robviglione, @HorizenLabs, @horizenglobal, and @ZKVProtocol on X.