One night in 2017, Iron Fish founder Elena Nadolinski attended a birthday party at the Palo Alto home of Protocol Labs founder and CEO Juan Benet. Her then-boyfriend, now-husband and Figma co-founder, Dylan Field, had been roommates with Benet, and they were part of a close group of friends. The party was filled with talk about cryptocurrency generally, and Ethereum specifically. Benet’s company had started Filecoin, a cryptocurrency-operated file storage network, and he was about to roll out the InterPlanetary File System (IPFS), a decentralized storage and file referencing system that can operate on Ethereum.

Something about the conversation struck her as particularly urgent—all these “incredibly brilliant people, being all very excited about this piece of technology”—cryptocurrency, but it was still too complicated for most people to widely adopt it. It required hours of setup, some technical knowhow and access to powerful computers. To Nadolinski, who had had immigrated to America from Russia when she was 8, it seemed like two ideas in opposition: cryptocurrency promised to be a currency for the people, by the people, but it was still limited to those with the resources and ability to immerse themselves in technology to participate. What about the rest of the world? On the way home, Nadolinski sat shotgun, phone in hand, scrolling down an internet wormhole as Field drove across the dark city. 

She Googled: “What is Ethereum?”

Nadolinski had been recognized as a teen by the White House as an up-and-coming computer science superstar, interned at Microsoft and had been recruited as an engineer by the buzzy startup Tilt, and then worked at Airbnb, but she admits that by the time of this party, she didn’t really get the technology that powers the second-most-valuable cryptocurrency. “It’s inaccessible for even a smart, technically savvy person,” she says. She Googled: “What is Ethereum?” and flicked through the results. When she remembers this moment now, she laughs at herself trying to get to the bottom of a set of wildly complex questions while driving home from a party. 

“Ethereum is this world computer, right? So, okay, that’s a really big phrase. What does that mean? Ethereum does distributed computations. Again, what is that? That seems confusing. And so the first kind of use case that I read about it was something to do with decentralized voting. How do you make voting more fair? And I thought, okay, that’s interesting, but that doesn’t seem like such a breakthrough. And so I kept kind of digging and digging and digging into it. And the first use case that actually made the most sense to me was non-fungible tokens.” She saw the non-fungible tokens, or NFTs—digital files whose proof of ownership can be stored on the blockchain, so a person can show they own the “original”—as a compelling use of the blockchain because they introduced scarcity to something that was previously considered endlessly replicable. Within several months, Nadolinski went from thinking about scarcity to charting a path to a more accessible cryptocurrency.

“And so I kept kind of digging and digging and digging into it. And the first use case that actually made the most sense to me was non-fungible tokens.”

elena Nadolinski

This is how Nadolinski, now 30, talks—moving from one massive idea to the next, toggling between tech lingo and business jargon in a rapid conversation style that makes concepts like “world computer” or “non-fungible token” easier to understand. After her Ethereum-Google in 2017, Nadolinski researched cryptocurrency ecosystems, reading white papers and speaking with founders, protocol developers and engineers. As a curious computer scientist, she was drawn to the complexity. But as a person, she was drawn to cryptocurrency’s close-knit community and its members’ enthusiasm for its possibilities. She started attending hackathons and meetups, asking questions, offering solutions, making friends and contributing in such a meaningful way that she started receiving invitations to present. Soon, she stepped away from her job at Airbnb to pursue cryptocurrency full-time.

Today, Nadolinski and her team are close to launching Iron Fish as a layer 1 blockchain to support a new cryptocurrency as well as a privacy layer for other existing cryptocurrencies. Cryptocurrencies are the least private way of transacting; the transparency of crypto transactions is the pillar of trustless verification. It means anyone could track an individual’s crypto transactions in real time using data-mining techniques. Since crypto digital wallets have unique addresses, their transactions can be traced by cross-referencing with personal data. And even while some cryptocurrencies are private, and others can be made private, the processes are cumbersome, confusing and still may be vulnerable to deanonymization. All transactions on Iron Fish are encrypted, protecting the user by hiding transaction information through a cryptographic technique called zero-knowledge proofs. Eventually, as Iron Fish becomes more mature and integrates with more existing blockchains, any cryptocurrency transaction can be made private in a compliant way. This means that, some day, users could have all the advantages of any cryptocurrency without the privacy issues that currently plague it.  

The name Iron Fish alludes to the protective power of cryptography. During World War II, the United States used codes to communicate with allies that were based on Native American languages, spoken by Native American enlisted men called Code Talkers. The code, never broken, was declassified in 1968. Nadolinski chose the word Iron Fish, meaning submarine—“besh-lo” in the code derived from the Diné (also known as Navajo)  language—because the idea of a submarine was strong, protective and something secret, or in this case, private. 

Issuing currency is a primary function of modern governments, which enact policies to keep it stable so a nation’s economy can function. Cryptocurrency can be a way to hedge against the inflation or deflation that comes with traditional currencies. “For people in the United States, it’s like, well, ‘I think maybe it’s nice in a moral, philosophical way for me to hedge my bet in terms of which currency I keep my wealth in,’” Nadolinski says, “but for other people in Venezuela, Turkey, Argentina, Russia, Ukraine, all those countries are experiencing inflation … if they could have a way out …” Beyond that practical application, Nadolinski’s company is part of a rapidly growing cohort of encryption and privacy tools—messaging, browsers and VPNs—designed to protect users from the threat of data scraping, surveillance and hacking. “Freedom is synonymous in many ways with privacy,” Nadolinski says. “So even though Americans have forgotten how good they have it, there are so many arguments for them to still care about private cryptocurrencies.” Sequoia Capital partner Shaun Maguire understood the promise of Iron Fish the moment he heard about it, and Sequoia invested in November 2021. With a deep technical background, Maguire had heard about the promise of blockchain technologies since at least 2007. So when he met Nadolinski more than a decade later, he was intrigued by her vision for realizing blockchains’ potential for usability and privacy. 

Maguire imagines a scenario where Iron Fish would be even more necessary—a hypothetical future in which cryptocurrencies are used for everyday transactions, in which it would be possible for scammers to see people’s anonymous-but-public transactions and trace them back to a wallet and know where that person is, what they’re doing, and even what they’re planning to do. “Imagine you’re buying an airline ticket to fly from L.A. to Europe,” Maguire says. “So someone can guess you’re going to be out of town for the next week and they can go rob your house.” Nadolinski also tells a story about speaking to a good friend who said they wanted a private cryptocurrency to spend at Burger King, because they didn’t want their health insurance provider to know about their diet habits and raise their rates. This is only partially hypothetical. At the moment, cryptocurrencies cannot be spent at Burger King, but can be spent at McDonald’s, and retailers like Amazon, Overstock, Microsoft and AT&T, among others.

Nadolinski and her parents immigrated to America when she was in elementary school. They lived in several places but eventually settled in Virginia. She spoke little English and her parents held her back a year so she’d be in the same grade as another student who spoke Russian and English. This was a disaster; Nadolinski remembers her as a bully who intentionally mistranslated things. So Nadolinski pushed herself to learn English rapidly at school, and as she grew up, she found a cohort of “supersmart, badass” girlfriends who “all wanted to change the status quo.” Her parents worked as software engineers, and she’d page through their books at home. In high school, she took her school’s AP computer science class and taught herself everything else she’d need to know to become vice president of the computer science club and president of its robotics club. She loved her teammates, the kind of kids who liked to tinker and code, and who, she jokes self-awarely, “liked to stay after school for hours to make sure that the robot goes straight.” The robots went straight enough that the team earned a second-place finish at a global competition. She was honored at the White House with the Aspirations in Computing Award from the National Center for Women in Information Technology, and the Central Intelligence Agency gave her an award, recognizing a program she designed to compress images. The irony doesn’t escape her today, pointing out that image compression is related to encryption, which the CIA knows something about. 

Nadolinski first heard about cryptocurrency in 2011. During a fundraising brainstorm for the robotics team, a teammate suggested they use the school’s computer lab to mine Bitcoin. The currency was still new, and worth between $1-$30 each. Nadolinski shut the idea down, saying, “That’s silly. It’s never going to work.” And just as her opinion of cryptocurrency from 2011 has evolved, the rest of the world is catching up. Larry David starred in a 2022 Super Bowl commercial, playing a character who scoffs at the wheel, ridicules the light bulb and mocks the indoor toilet. The commercial was for FTX, a notably accessible cryptocurrency exchange. Today Nadolinski laughs, ruefully describing how if she’d been game for the idea, the team would, in all likelihood, be perpetually endowed. As of this writing Bitcoin trades at about $20,000, and has been as high as $68,000.

After graduating high school, Nadolinski studied computer science at Virginia Tech in Blacksburg. During the school year, she interned at the cloud computing services company Rackspace for engineer Dave King, who is still a mentor and friend. For up to 10 hours a week, she tackled a backlog/wishlist of “tiny tickets,” but King remembers one of Nadolinski’s projects that was “not that tiny.” He says she handled the moment gracefully when managers suddenly realized that some code she’d been updating impacted several other pieces. “We thought it was scoped, and it was clearly not scoped,” he says with a chuckle. It launched Nadolinski into a nine month project, “She was in rooms seeing how implementation might happen and seeing how to make the decision,” King says. “I think Elena was quite fastidious in attention to detail … which is something that brought her success. She was good in collaborative situations, as the intern, understanding how people made things work and fixed things.” 

“She had a healthy skepticism about the information she was getting, and really getting into the details of things to understand what was going on.”

dave king

King says great engineers are distinguished by their ability to figure out ways to get around problems, something he saw in Nadolinski immediately. “Like, there are five little hurdles. Which ones are the ones we invest in to fix? And which ones do we just let go? Knowing how to manage your time, making choices for today and the future. Some people are like, ‘We have to fix everything all the time.’ And that is not as productive.” Nadolinski spent summers interning for Microsoft in Redmond, Washington, and after graduating in 2015, she took a full-time job there. Nadolinski realized she loved collaborative building but hated bureaucracy. After a year, she moved to San Francisco to immerse herself in the more collaborative startup world. She got a job working again for King, this time at the new crowdfunding company Tilt, but it was acquired by Airbnb about seven months after she started. “She was asking me about the user acquisition strategy,” says King, remembering Nadolinski as being particularly savvy about business even as she was working on the engineering side. “Tilt went international to grow our customer base, and signups were very high, but you can only go into so many new markets,” he continues. “And we had a conversation like, ‘Is this really going to work?’ And she didn’t get the answers she really wanted … and when we took the acquisition, I was like, ‘Oh, Elena figured this out six or seven months ago.’ She had a healthy skepticism about the information she was getting, and really getting into the details of things to understand what was going on.” 

Now at Airbnb, several months after the Ethereum epiphany at the birthday party, she attended EthWaterloo, a 36-hour Ethereum hackathon in the Canadian computer science hub of Waterloo, Ontario, which attracted hundreds in October 2017. There, she worked on the problem of how to enable decentralized video streaming on the IPFS. She talks about how problem solving in one area unlocked insights in other areas: “And that got me to ask, ‘What is decentralized computing,’ and ‘How do you prove an honest computation?’” That thinking led her to zero-knowledge proofs, which use cryptographic techniques to verify transactions without exposing user data, which is now a big part of how Iron Fish works. But it was more than the thinking and problem solving that made EthWaterloo a turning point for Nadolinski. She tells a story about how at 3:30 a.m., Dan Finley, the man who wrote MetaMask, a cryptocurrency wallet for Ethereum, helped her debug her own MetaMask integration. “And that was a very special feeling. It was like, ‘Wow. This community is so welcoming and so encouraging and is so available to help.’ And so, from that hackathon in particular, it’s like, ‘Wow, I want to be part of this.’” She went on to attend and present at more hackathons, giving talks while live-coding non-fungible smart contracts onstage in about 30 minutes. She says she wanted to encourage more people to experiment with Ethereum, to see this emerging technology as approachable. And it started to work. Focused on being relentlessly pragmatic and approachable as opposed to theoretical, Nadolinski became an in-demand speaker and collaborator. When she gave a talk called “Demystifying Zero-Knowledge Proofs” in 2018 at Devcon IV in Prague, tracing the history of cryptography through to its involvement in cryptocurrency today, people reached out on Twitter and Telegram, thanking her for making such a complex topic so understandable and asking how they could start learning more themselves. 

“And that was a very special feeling. It was like, ‘Wow. This community is so welcoming and so encouraging and is so available to help.’ And so, from that hackathon in particular, it’s like, ‘Wow, I want to be part of this.’

elena nadolinski on her experience at EthWaterloo in 2017

After that talk, she was invited to speak at EthBuenosAires in 2018, the first event of its kind in Latin America. At the same time, Airbnb wanted her to go to Barcelona for a user-research study, a rare, exciting opportunity. She was torn. She was constantly learning from her colleagues at Airbnb, and appreciated the company’s focus on aesthetics, but she’d already booked the trip to Argentina. “That was the turning point of, like, ‘Okay, I feel like I have two jobs, and I’m sucking at both of them, and I need to choose one,’” she remembers. “And I obviously chose crypto.”

“So, I was looking into NFTs already,” she continues. “I was looking into zero-knowledge proofs, and I worked backward. I said, ‘Okay, let’s just assume that in whatever time horizon, crypto payments are going to be ubiquitous, whatever that means. What do we need to get there?’” Privacy seemed like the obvious answer. She explains that today’s levels of transparency are unsafe for users, as in Maguire’s hypothetical plane ticket-buying scenario, but also unsafe for nations. “Everything that you do on any kind of most known blockchains is fully transparent to the world,” she says. “If you use Ethereum or Bitcoin today, your wallet information is available to anyone in the world to see what exchanges you use, what items you have, what protocols or smart contracts you’ve ever interacted with.”

By 2018, ZCash rolled out an open-source protocol called Sapling to try to solve for privacy with zero-knowledge proofs. All forms of currency, whether cash, credit or digital, face the challenge of making a transaction private enough so people feel free to use it in everyday life, while enabling regulators to ensure all transactions are legal. And this balance makes cryptocurrency innovation especially tricky. But this was Nadolinski’s passion, and, after raising funding in 2021 to start hiring a team, it would become her business model: users would move their cryptocurrencies to Iron Fish’s blockchain, which would cloak their assets by anonymizing and encrypting their data, and the miners who add to the blockchain would receive a fee paid in the Iron Fish token, $IRON. This incentivizes use of $IRON for everyone who wants to move their currency to the Iron Fish blockchain. The cryptocurrency community is still figuring out a balance between privacy and minimizing crime committed with cryptocurrency. A crypto wallet typically has a private key, which is analogous to a password, to allow the user to spend their funds, and a public key, to allow the user to request funds. Most privacy-preserving cryptocurrencies, including Iron Fish, also support view keys, in addition to private and public keys, at the wallet level. Initially, only the creator of the wallet has access to that wallet’s private, public and view key. The holder of a view key can see all associated transactions with that wallet, even in a fully private system. This allows regulated entities, like exchanges, to be compliant and provide audits. Nadolinski says her team is also working on adding controls on how a cryptocurrency can move in and out of the Iron Fish layer, a kind of monitoring capacity on the bridges between blockchains to limit hackers from taking advantage of the Iron Fish privacy platform. Nadolinski explains, “Crypto can’t go forward without privacy. But the future is going to be privacy-with-compliance. That’s what we are working on at Iron Fish.”

Nadolinski is also working to make Iron Fish especially user-friendly. The Iron Fish core team has a mantra to make Iron Fish “the Apple of blockchains”—inuitive, easy to use and something that works right out of the box. “And it’s actually very difficult to make it work out of the box, because it’s really complicated tech, but we’re trying our best,” Nadolinski says with a self-aware laugh. To get there, she and her team consistently survey early users for feedback about the blockchain implementation and the wallet. And she’s been inspired by Airbnb’s use of design, she says, to make an otherwise unusual experience—“You go into someone else’s house and you sleep on their bed,” or using cryptocurrency—cool. She points to how several private currencies feature black websites, with code-style text or pirate motifs, aesthetics that speak to secrecy, but which are not universally appealing. Her site has inviting language and features bright colors and sea creatures rendered in a woodblock aesthetic. One fish wears sunglasses. But her biggest point of user-design pride is the installation process. Instead of a typical cryptocurrency setup, a multi-step ordeal that can take up to three hours, anyone can run an Iron Fish node using just one command line in the terminal.

In May, Nadolinski launched Iron Fish’s second incentivized testnet, a standard way to ensure a new blockchain is stable and bug-free, in which a working version of the blockchain is used by a limited cohort who spot problems in the code and try to stress-test the system. Phase two is wrapping and Phase 3 will launch in the first quarter of 2023, aiming for a mainnet launch in the third quarter. Participants earn $IRON tokens in exchange for certain kinds of participation. At its peak so far, the second testnet has hosted 11,000 concurrent nodes. Bitcoin, the most-used cryptocurrency, for comparison, typically hosts about 15,000 concurrent nodes. “I think that is a testament to how easy it is to run Iron Fish,” says Nadolinski. 

“These testing phases are very stressful because it’s like, if you miss one thing in mainnet, you’re really screwed.”

shaun maguire

This testnet is the last one before the team pushes the blockchain live. Stakes are high. This phase is so critical because, unlike traditional software that can be updated to fix bugs or add features, big changes can break the blockchains themselves. “These testing phases are very stressful because it’s like, if you miss one thing in mainnet, you’re really screwed,” says Maguire. While small updates can be rolled out without breaking the chain, to make a big update, a coordinated effort has to occur in the community of exchanges, miners and users to accept the change, a difficult proposition for a technology spread across a global community. Maguire observes that big code changes where the currency survived the disruption have only happened a handful of times, notably with Ethereum and Bitcoin. “These things were catastrophically painful conversations in these communities and took years to settle,” Maguire says. “So once you ship crypto code, it’s basically final.” And bad code can be a disaster. Estimates of how much cryptocurrencies hackers are stealing vary widely, but the numbers are notable. The Federal Trade Commission reports that Americans lost $1 billion in 2021, but the FTC acknowledges that its reports represent a fraction of the likely total. The blockchain analytics firm Chainalysis, which doesn’t guarantee its data, estimates that $14 billion worth of cryptocurrencies has been stolen because of weaknesses in code.

Nadolinski says the Iron Fish testnet is now processing more zero-knowledge proof transactions than any other chain. But she is balancing development and optimization with the pressure to launch. Iron Fish’s value depends on getting people to want to use it, and testnets create the kind of buzz that leads to adoption. Maguire speaks to the pressure from the community: “They’re like, ‘We’re desperate. Get this thing out. We want to use Iron Fish in production.’” Nadolinski is sensitive to that sense of urgency. After all, she’s doing all this because of the cryptocurrency community, which she got introduced to through her husband, Field. “He is one of the most connected people I’ve ever met,” she says. When she was at Microsoft, Tilt started recruiting her, so she Googled its co-founders, James Beshara and Khaled Hussein. She spotted Beshara in the 2015 Forbes’ 30 Under 30 list for Consumer Tech. Also in that year’s cohort was Field, pictured with a tremendous grin, one that makes him stand out on the page, still searchable today. “And I scrolled past this face, and it was like, ‘Wow. This person’s my age, was an intern at Microsoft, started a company, raised $3 million.’ I was like, ‘Whoa. I thought I had to have years of experience to do this. And here’s a person who just did it.’” 

Shortly thereafter, she accepted the job at Tilt, moved to San Francisco, broke up with her boyfriend and gave in to her friends’ prodding to join a dating app. One day, she chose OKCupid and started scrolling. “I was like, ‘Oh my gosh, where did I move?’ There was that phrase: the odds are good, but the goods are odd. Yeah. And I kept scrolling and scrolling and scrolling, and getting kind of depressed. Then I see a face, and I thought, ‘Whoa, I recognize that face.’”

“And I scrolled past this face, and it was like, ‘Wow. This person’s my age, was an intern at Microsoft, started a company, raised $3 million.’ I was like, ‘Whoa. I thought I had to have years of experience to do this. And here’s a person who just did it.’”

elena nadolinski on her first encounter with dylan field

She says she assumed Field was out of her league, but she wanted to start her own company and hoped he’d agree to meet to talk shop. He was the first and only person she messaged, asking him either to coffee or lunch, and dropping in a link to her LinkedIn profile. Field responded enthusiastically, but said that the LinkedIn link was a first for him on the dating site. Nadolinski laughs telling the story now: “I was privacy-conscious and my OKCupid account had almost no information. It had a picture, but you couldn’t tell it was me.” She’d posted only one image, a picture taken from far away. In it, she wears glasses, which she typically doesn’t. “It had my age and my height, because I thought that was important. I’m very short. And my Facebook wasn’t publicly accessible. So I wanted to show him that I’m a real person. The only way I thought of doing that was my LinkedIn profile. It was a very logical decision.”

He replied that lunches were hard, but he could do dinner. It’s not lost on Nadolinski that she had to design her own privacy-protecting solution for interacting authentically on a dating app. They’ve been together ever since. When Nadolinski talks about founding Iron Fish, she focuses on how the tech community, and the cryptocurrency community specifically, rewarded her curiosity and generosity with help and encouragement. Her appreciation for how that community has been uniquely accessible in spirit, even if not in technology, is what she’s built Iron Fish around. Now she’s poised to make the community she loves so much even larger, sharing it through greater accessibility—with most anyone with a computer, or two, and internet access. “A lot of people around the world are excited about blockchain. They’re excited to participate in a new layer 1 project,” Nadolinski says. And with her focus on pragmatic solutions and that user-friendliness, she’s excited to help them as a member of a community that has helped her so many times.