Securing Bitcoin has always been a challenge. While a simple 12-word recovery phrase provides ultimate control over one’s funds, it also introduces major risks—loss, theft, or even physical extortion. Over the years, solutions like multi-signature wallets and miniscript setups have emerged to enhance security, but these often come with complexities and new vulnerabilities as they require backups of wallet metadata. Many users end up relying on centralized services to store their critical backup data, which reintroduces trust and dependency into a system designed to eliminate them.
Enter Rewind Bitcoin, a new approach to Bitcoin security that leverages time-based protection and decentralized storage to ensure funds remain safe—even in the worst-case scenarios. By utilizing peer-to-peer (P2P) technology through Pear Runtime, Rewind Bitcoin removes the need for centralized backup services, ensuring users have full control over their Bitcoin without external dependencies.
In this interview, José Luis Landabaso, creator of Rewind Bitcoin, shares his journey from finance and tech to Bitcoin, how he identified key security flaws in existing Bitcoin storage methods, and why decentralization is the future of digital asset security.
Q: Before creating Rewind Bitcoin, what was your background in technology and finance?
Before diving into Bitcoin, I had a background in computer vision and finance. I studied telecommunications engineering and later specialized in computer vision, eventually completing a PhD in the field. Early in my career, I worked on research and development, but I became increasingly interested in financial markets and investing. That curiosity led me to create La Bolsa Virtual, a stock market simulator that became quite popular in Spain, attracting over 800,000 registered users.
It was during the Bitcoin bull run of 2016-2017 that I finally decided to take a serious look at it. Initially, I was skeptical—I saw it as a speculative bubble, something that people used to gamble and lose money. But as someone with a strong technical background, I wanted to understand why it was gaining so much traction. I read Satoshi Nakamoto’s whitepaper, and that changed everything. The elegance of the system blew my mind. I couldn’t stop thinking about how it solved the double-spending problem and how it removed the need for trusted third parties in financial transactions.
From that moment, I became obsessed with Bitcoin. I spent weeks consuming everything I could find—its technical, economic, and philosophical aspects. The more I learned, the more I realized that Bitcoin wasn’t just another tech trend—it was fundamentally reshaping financial sovereignty. That’s when I decided to dedicate myself 100% to Bitcoin development.
Q: What security problem did you identify in Bitcoin storage that led to the creation of Rewind Bitcoin? How did your discussion with Adam Back shape this idea?
One of the biggest security issues in Bitcoin is custody. A 12-word recovery phrase gives you full control over your funds, but it also makes you vulnerable. What if you lose it? What if someone forces you to reveal it? While Bitcoin is cryptographically secure, real-world threats are much more practical. Attackers don’t need to hack the system—they just need to show up with a wrench and force you to reveal your keys.
Multi-signature wallets were introduced to mitigate these risks, requiring multiple keys to sign transactions. However, this created new complexities—users now had to manage multiple keys, and if they lost one, they risked losing their Bitcoin forever. This gave rise to custodial services that, in practice, acted as backup providers for both keys and for wallet metadata.. But that brought back the problem of trust and centralization—Bitcoin was designed for self-sovereignty, yet users were relying on third parties again.
The idea for Rewind Bitcoin came from a conversation I had with Adam Back, one of the most respected cryptographers in the Bitcoin space. I was exploring different ways to improve Bitcoin security when I reached out to a Telegram group where Adam was active. I asked, “What security problems in Bitcoin still need solving?” Adam suggested the concept of Bitcoin Vaults—a time-delayed mechanism to protect users from forced extractions or physical threats.
That’s when I had the breakthrough: Instead of relying on spatial security (storing keys in different locations), we could use time-based security. Imagine your Bitcoin is frozen inside an ice block. The larger the ice block, the longer it takes to melt. If an attacker tries to steal your funds, they can access your key, but they won’t be able to spend it immediately. That delay gives users time to redirect their Bitcoin to a safe location before the attacker can use it.
This concept, implemented using timelocks in the Bitcoin protocol, ensures that even if someone gains access to your wallet, they still can’t steal your Bitcoin instantly. The conversation with Adam Back was pivotal—it confirmed that this was an important problem worth solving and gave me the confidence to move forward with building Rewind Bitcoin.
Q: How did you discover Pear Runtime, and what convinced you to use it in Rewind Bitcoin?
While developing Rewind Bitcoin, I realized another major issue: how to store backup data in a decentralized and trustless way. Advanced wallets like multi-signature setups don’t just require private keys—they also need metadata and scripts describing how the funds are locked. These “security maps” are too complex to write on paper, so they must be stored digitally.
Most users store these backups on USB drives, cloud storage, or centralized services, which creates significant risks—data loss, hacks, or third-party failure. Companies like Casa or Unchained Capital offer backup services, but again, this reintroduces reliance on a trusted entity.
I didn’t want to store this data for my users, and I knew Bitcoiners wouldn’t trust me to do so. That’s when I discovered Pear Runtime through a tweet by Paolo Ardoino. It immediately caught my attention because it reminded me of BitTorrent, but applied to decentralized application storage.
At first, I was skeptical—I assumed it would be difficult to integrate. But once I started experimenting, I was blown away by how simple and powerful it was.
Q: What was your experience integrating Pear Runtime into Rewind Bitcoin?
Honestly, I expected integration to be a challenge, but within a day, I had a working prototype. The documentation was clear, and the design was intuitive.
With just a few lines of code, I modified Rewind Bitcoin so that users could store their security maps in a fully encrypted P2P network instead of relying on my servers. Now, every user contributes to the network, encrypting and distributing their backups across multiple peers. This means that even if Rewind Bitcoin disappears, the backups will remain intact, and users will always have access to their wallet metadata backups.
What amazed me was how seamlessly it removed all central points of failure. Now, users don’t have to rely on me or any company to keep their data safe—it’s fully distributed, encrypted, and resilient. It was exactly what I needed to make Rewind Bitcoin truly decentralized.
Q: How do you see the future of Bitcoin and decentralized applications?
Bitcoin has proven that a decentralized system can survive and thrive without a central authority. If we want to build truly secure, long-lasting applications, we need to follow the same principles. Pear Runtime enables a new wave of decentralized applications that don’t depend on a single entity.
My goal is to make Rewind Bitcoin completely decentralized. The only centralized element right now is fetching the BTC/EUR exchange rate, but even that could become community-driven. Eventually, I hope that anyone who values Bitcoin self-custody will also run a Rewind node, just like they run their own Bitcoin node today.
If we want Bitcoin to remain unstoppable, we need applications that are just as resilient, trustless, and decentralized as Bitcoin itself. Rewind Bitcoin + Pear Runtime is my contribution to that vision.
