Andrew Stone presents at Web3 Amsterdam on 14 March 2025. He explains how applied blockchain technology is a new form of language, arguably, the first expression of a new form of language where there is real power behind statements. In this case, a user of a blockchain who decides to create a transaction is given force to effect a transfer of ownership of some property and also any conditions attached to the transfer. All other languages are embodying concepts, abstractions of ideas, objects etc. This important perspective reveals how revolutionary blockchain technology really is. Andrew continues by showing how Nexa harnesses this new language through NexScript and its native miner-validated tokens, which can represent many different objects.
Presented at Web3 Amsterdam, transcribed and adapted from a live speech.
As you can see from the title behind me—“Revolutionizing Blockchain: An Introduction to Nexa”—we’re diving into something exciting today. You’re about to hear a perspective that aims to clarify and reframe how we think about blockchain. Like many of you, I’m intrigued to see how this all unfolds. So let’s get into it.
I’m Andrew Stone, the lead developer of Bitcoin Unlimited. I’m not a professional speaker, so bear with me—and the mic—if things get a little bumpy.
My mission is simple but ambitious: to create sound cryptocurrency that people can use in their daily lives. That’s the ultimate goal for any meaningful blockchain project. With that in mind, I asked myself: What do I want you to take away from this talk?
I think the biggest takeaway should be this: a deeper understanding of what blockchains really are. That may sound basic, but even seasoned developers can lose sight of it amidst the complexities of their own projects. Have you ever sat down at dinner, tried to explain blockchain to someone, and found yourself struggling to put it into words? I see some of you smiling, so I know I’m not alone.
It’s a complicated concept, but I want to try and boil it down to its essence—and then show you why that foundational understanding led us to build Nexa the way we did.
The Blockchain as a Language of Ownership
At its core, I believe a blockchain is a language—specifically, a language of ownership. In fact, I’d argue it’s the first real language of ownership. You might say, “But wait, what about contracts?” Sure, when you buy a house, you sign a contract—pages of natural language describing rights and terms. But those documents represent ownership; they don’t embody it.
This is subtle but important. Think of it like magic in a fantasy movie: a wizard says “light” and poof—light appears. The language itself has power. In the real world, saying “light” does nothing; it’s just a symbol for a concept. But in a blockchain, the language—through code and consensus—directly enforces ownership.
And here’s the wild part: on most blockchains, you can’t lie. If you try, the system rejects your statement. Some platforms like Ethereum might still charge you for a failed transaction, but the point remains: the protocol itself won’t accept falsehoods. I don’t know of any other language with that property.
Building Nexa Around This Philosophy
So, how did we take this concept and use it to build Nexa?
We asked: What makes a great language? Key traits include expressiveness, succinctness, and performance—or, in blockchain terms, scalability. In any language, people need to carry on multiple, independent conversations simultaneously. That’s a given in spoken languages, but in blockchain, it’s a technical challenge.
With Nexa, we approached it as constructing the best possible language for expressing and enforcing ownership. That’s why we built it around the UTXO model. Compared to EVM-based systems, UTXOs offer powerful parallelization and independence—allowing users to hold and use their assets without stepping on each other’s toes.
We chose Proof-of-Work deliberately. While this is a hotly debated topic, I believe it strengthens the integrity of the blockchain language. Why? Because statements made on the chain are backed by real energy. To undo or manipulate them requires actual effort and cost—unlike Proof-of-Stake, where changes can sometimes boil down to social consensus or coordination, as we saw with the recent Ethereum controversy.
Nexa’s Unique Features
We designed Nexa with a two-minute block time—fast enough for usability but still secure. We also implemented double-spend proofs, which instantly detect and block attempts to cheat. If someone tries to lie, the system spots it before the lie can spread.
And critically, we’re a fairly launched coin. That means no surprise inflation or secret token dumps. Ownership on Nexa is what it appears to be—no tricks, no hidden billions.
Now, when you talk to traditional Bitcoiners, many still argue that blockchains should only support native tokens. But if you view blockchains as languages, that doesn’t make much sense. Languages need objects. Think about it: if all your language lets you say is “I bought [one thing],” how useful is that?
That’s why Nexa fully supports tokens. In this language, nouns are people, verbs are contracts, and tokens are the objects. We want rich, meaningful interactions.
Interactive Transactions: A Living Conversation
One of the most exciting capabilities in Nexa is what we call multi-party interactive transactions. Here’s how it works:
Let’s say I make an offer: “I’ll trade some NEXA for a token.” I sign that statement. Later, without any further input from me, someone else can complete the transaction by offering the token. The offer is alive on-chain, built into the blockchain language.
That QR code you might’ve seen on the slide? It doesn’t link to a centralized site. It is the offer—encoded directly into the language. You scan it, and your wallet understands the deal. That’s what it means to have a living language of ownership.
Unlike some EVM-based chains where hacks worth billions can occur—and we’re left wondering if it was a UI bug or a contract flaw—Nexa’s architecture ensures clarity and transparency. Your wallet shows exactly what changes are about to occur before you hit confirm.
Final Thoughts
I’m out of time, but I want to leave you with this:
We built Nexa not just as another blockchain, but as an evolution of how we communicate ownership. A language where truth is enforced, lies are rejected, and every user can speak freely—with power and protection baked in.
Thank you all.