Pubky Launches as Censorship-Resistant Social Media Upgrade

Pubky, a decentralized web protocol and social media platform developed by Synonym, is gaining attention as a potential evolution of decentralized social networking. Launched in beta during BTC Prague in early August 2025, the project is described by its CEO, John Carvalho, as a “strict upgrade” to Nostr, a protocol that has gained traction among the Bitcoin community due to its Lightning Network integration and decentralized nature. Pubky is designed to address perceived flaws in Nostr’s architecture, particularly its censorship vulnerability and user experience shortcomings [1].

At its core, Pubky replaces traditional account-based systems with cryptographic public keys, allowing users to own and control their digital identity and data directly. Rather than relying on platforms to store identity and content, Pubky leverages decentralized tools such as PKARR, Mainline DHT, and homeservers to enable users to manage their digital presence independently. This approach ensures content and identity are portable, verifiable, and signed, creating a foundation for user sovereignty [1].

One of Pubky’s key innovations is its Public Key Domains (PKDs), a censorship-resistant alternative to traditional DNS. PKDs are tied to users’ public keys and hosted across a hardened DHT with redundancy and signed records, making it nearly impossible to censor or remove content. If a user’s data is blocked by a particular server, they can seamlessly move to another, maintaining their identity and data integrity [1].

Carvalho highlighted several issues with Nostr, including poor app quality, broken search functionality, and an inconsistent user experience. He argues that these issues stem from fundamental design flaws in Nostr, which could lead to large-scale censorship as the protocol scales. Unlike Nostr, which relies on multiple free servers to host user data, Pubky offers a more robust discovery mechanism via its PKDNS system. By using public keys as domain names, Pubky ensures that data can always be located through a decentralized network of millions of nodes, regardless of where it is hosted [1].

Legal liability is another area of concern for Carvalho. He notes that hosting social media content is subject to legal compliance in most jurisdictions, particularly regarding child safety, copyright, and harassment laws. While hobbyist Nostr relay operators may avoid scrutiny, those seeking to build businesses on top of the protocol face potential legal risks. In contrast, Pubky enables users to move their data and identity freely if they face censorship, reducing reliance on any single server or jurisdiction [1].

Running a Pubky homeserver differs from running a Nostr relay in key ways. While Nostr relays function as data pools, Pubky homeservers serve as single sources of truth for user data. This data is then indexed and replicated by a separate system of indexers, which aggregate all Pubky data into a structured graph database for improved application performance and user experience [1].

Pubky differentiates itself from other decentralized social media protocols such as Hive, Farcaster, and the Fediverse by emphasizing public key-based identity and censorship resistance. While Carvalho acknowledges the relevance of platforms like Bluesky, he highlights the absence of a PKDNS-like system in most alternatives [1].

Currently, Pubky is in beta, with its flagship application available at pubky.app. Invite codes can be requested via X by following @getpubky. The protocol and software are open-source and hosted on GitHub. Carvalho also emphasized that Pubky is a central component of Synonym’s broader “Atomic Economy” vision, which includes other projects such as Bitkit, Blocktank, Paykit, and Atomicity, aimed at building a functional and sustainable free-market society [1].

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[1] What is Pubky? (https://blog.bitfinex.com/education/what-is-pubky/)