Moxie Marlinspike: The Cypherpunk Pirate Who Built Signal

Did you know that your daily messages on chats like WhatsApp and Facebook Messenger are encrypted thanks to this man? Considered a late cypherpunk and anarchist, Matthew Rosenfeld (better known as Moxie Marlinspike) is a remarkable American cryptographer and creator of privacy-focused digital tools for everyone.

Marlinspike was born in the early eighties, grew up in Georgia, and moved to San Francisco as a teenager. His heroes by then were already the first cypherpunks. He had an adventurous side, not only in computers but also in real life. In the early 2000s, he bought an old sailboat with friends, fixed it up, and traveled through the Bahamas while documenting the trip in a film project called ‘Hold Fast’. His passion for sailing matched his curiosity about technology, where he was already making a name for himself by studying weaknesses in Internet security systems.

By the end of that decade, Marlinspike had already shaken things up with research on SSL, the system meant to keep online browsing secure. He didn’t just point out flaws; he also suggested ways to improve them, like with his project called Convergence. He even created services like GoogleSharing, which allowed people to search the web more privately. His work caught the attention of big companies, and not long after, he ended up leading security efforts at Twitter, a role that opened the door for wider recognition.

After leaving Twitter, Marlinspike turned more of his energy to building tools for communication. Over the years, his projects gained the trust of millions of people who wanted their conversations to stay private. Eventually, all of this effort led to something that became much bigger: the creation of the Signal app and the encryption protocol behind it.

The No Network Effect

The reason why Marlinspike has been building numerous privacy tools is likely because of what he’s dubbed the “No Network Effect” —or a choice that it’s not really a choice at all. Imagine you decide you don’t want a smartphone. On paper, it’s a choice you’re free to make. But when your friends text each other instead of making plans in person, when boarding a plane requires a digital code, and when group chats become the way people stay connected, that “choice” feels less like freedom and more like exclusion. A tool starts as optional, but once everyone adopts it, stepping away means stepping outside of society’s rhythm.

Phones are a clear example. They replaced older ways of coordinating, like agreeing on a meeting spot and sticking to it. Now, if you don’t have one, you’re left behind because the old system has dissolved. The illusion of choice is there—you can refuse the device—but the cost is high: missed connections, social isolation, even reduced access to basic services.

This matters for privacy because most of these technologies quietly trade convenience for surveillance. Now, fighting the No Network Effect doesn’t mean refusing progress altogether, but demanding tools that let us participate without giving up control. Moxie’s work, like creating secure apps, shows one way forward: build alternatives that let us stay in the network (the society) while keeping our privacy intact.

Open Whisper Systems

With that idea of privacy in mind, back in 2010, Marlinspike and roboticist Stuart Anderson launched a small startup called Whisper Systems. Their idea was simple but ambitious: create tools that could make smartphones far more secure and private. Among their creations was TextSecure, which allowed private text messaging, and RedPhone, which enabled encrypted calls. They also built WhisperCore, a system to protect everything stored on a phone, and other apps like WhisperMonitor and Flashback. These projects weren’t just experiments; they were meant to give ordinary people stronger control over their data.

Not long after, in 2011, Twitter acquired Whisper Systems. The company’s main interest was bringing Marlinspike’s expertise into its own security team, and while some of the apps briefly disappeared, Twitter soon released both TextSecure and RedPhone as open source. This move opened the door for a wider community to step in, ensuring the software would continue to grow rather than fade away. Marlinspike himself left Twitter in 2013, but he wasn’t done with the mission that had inspired him in the first place.

That same year, he founded Open Whisper Systems, this time as a collaborative project powered by volunteers and small grants. It carried forward the development of TextSecure and RedPhone, eventually merging them in November 2015 under a single new name: Signal. From there, the story began to reach an even bigger audience.

The Signal Protocol

Signal grew out of previous software like TextSecure, but its foundation came from another cypherpunk breakthrough: Off-the-Record Messaging (OTR), designed in 2004 by Ian Goldberg and Nikita Borisov. OTR introduced ideas like forward secrecy and deniable authentication, and Marlinspike reworked them into protocols that fit the realities of mobile networks, intermittent connectivity, and multi-device use, making encrypted messaging truly practical on smartphones.

At its core, the Signal Protocol mixes several advanced methods for encryption — including the Double Ratchet Algorithm and ephemeral prekeys — to make conversations private even if someone manages to steal old keys. This means that if one message gets exposed, past and future chats stay safe. The protocol became the backbone of the Signal app, which offers encrypted calls, texts, and media sharing across mobile and desktop.

In 2018, Marlinspike co-founded the Signal Foundation with Brian Acton, receiving $50 million in funding to ensure the project remained independent and open-source. As of early 2025, Signal had over 70 million active users and more than 220 million downloads, a sign of its global reach.

Besides, Signal’s influence extends far beyond its own app. WhatsApp, Google Messages, Skype, and Facebook Messenger’s “Secret Conversations” all adopted the Signal Protocol, bringing secure communication to billions of people worldwide.

It also gained public attention when Edward Snowden recommended it as a trustworthy tool for journalists and activists, while some governments criticized its strong encryption as a threat to surveillance powers. This mix of praise and pushback highlighted how a cypherpunk vision reshaped not just technology, but also global debates about privacy.

Centralization in Web3

Marlinspike has also given his two cents (and two Dapps) about the crypto space. Web3 may be a loose, fuzzy term to refer to the crypto-related software in general, but Marlinspike may have had a point in using it, even if he’s talked specifically about Ethereum. The truth is, his observations could be extrapolated to other networks as well.

He noted that while the idea of returning to a decentralized Internet is attractive, in practice, many people don’t want to run their own infrastructure. This leads to reliance on intermediaries, even in supposedly decentralized systems. Ethereum highlights the issue: most users and apps interact with it through a few companies like Infura and Alchemy.

That means control is consolidating into a handful of centralized services, which undermines the promise of Web3. Even wallets like MetaMask depend on these providers, so when platforms censor or change something, it can disappear from your wallet view despite still existing on-chain.

However, we must consider that centralization creeps in not only because of convenience but also because of how a network is designed. The architecture itself shapes how much power users really have. In Ethereum’s case, technical limits push people back toward trusted intermediaries. Other networks, however, take different paths. Obyte, for instance, is built on a Directed Acyclic Graph (DAG) and has no miners, “validators”, or other middlemen deciding what transactions go through. This gives individuals a higher level of autonomy and censorship resistance.

At this point, no system achieves perfect decentralization, though. Crypto still leans on centralized exchanges and wallets to bridge with the traditional world. But it’s a serious effort at giving people more control. As Marlinspike himself once wrote:

“We should never cease, even if all the banks burn and the dams of the world over come crashing down. It's what allows us to resist the institutionalization of our desires, the creeping bureaucracy, the language of patriarchy, or whatever we might find.”

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Featured Vector Image by Garry Killian / Freepik

Photograph of Moxie Marlinspike by Christopher Michel / Wikimedia