
An Exploration into Shielded Data Publication on Modular Blockchains: Bridging Privacy and Efficiency with Namada and Celestia
Note: There is active discussion in the community about renaming "Data Availability" to "Data Publication." As this term is less widely known at present, this post will use both terms interchangeably.

In the ever-changing landscape of blockchain technology, the need for robust privacy solutions runs parallel to the quest for efficiency and interoperability. This nuanced intersection offers ripe ground for both innovation and critical examination. Within this context, Namada presents a product idea that seeks to supplement Celestia's existing technology stack, notably in the domains of privacy and data availability.
Before diving into the details, it is essential to make clear that this blog post does not constitute an announcement of formal collaboration but is rather an exploration aimed at probing the reciprocal benefits such an integration might offer Celestia.
Understanding Celestia: A Brief Overview
Celestia is the first modular blockchain network that focuses on separating key components such as execution, consensus, data availability, and settlement. This modularity allows developers and users a heightened level of flexibility. They can choose their own virtual machines and execution environments, enabling customized experiences that suit specific needs.

Primarily, Celestia offers robust solutions for consensus and data availability, and it provides options for settlement layers like Ethereum, Solana, and custom rollups. By employing techniques like data availability sampling and erasure coding, Celestia strives to maintain a decentralized system while preventing data withholding attacks.
Shielded Data Availability via Namada
Recently, Adrian Brink, Namada and Anoma's co-founder, spoke at the Modular Summit in France, offering a compelling vision for a new approach to data privacy in the Celestia ecosystem. He introduced the concept of "shielded data publication," a development that could significantly alter the way we think about secure and anonymous online interactions.
Basically, in a privacy-focused rollup running on Celestia, users traditionally face a conundrum: how to submit transactions to Celestia without revealing their identity. While privacy-focused rollups do offer a degree of anonymity, the transparent fees that accompany transactions often pose a challenge to maintaining complete privacy.
Namada's Shielded Data Availability (DA) offers a nuanced solution to this problem. Using this method, a user can generate a zero-knowledge proof on their own device. This proof guides a set of Namada validators to submit the user's data to Celestia on their behalf. To external observers, the action appears to emanate from Namada's validator set. The beauty of this approach is that it could represent a single user or a group of 100 users, but the external world remains none the wiser.
By integrating Namada and Celestia, both systems can augment each other’s feature sets. Shielded DA, in essence, allows users to leverage the consensus and data availability solutions provided by Celestia, while maintaining the privacy guarantees offered by Namada.
Future Directions and Research Areas
Privacy in a blockchain context isn't just about hiding transactions; it's about where the data lives. In the current landscape, data exists in a globally readable database. However, in a privacy-preserving world, this data moves closer to the edge devices. This shift prompts questions about data storage solutions and the guarantees that can be offered to users regarding data recovery.
Another interesting research avenue is oblivious message parsing, a technique for querying data sources like Celestia without revealing exactly what is being looked for. This can be vital for services that need to access a wide range of keys in a Merkle tree without specifying which key they are interested in.
Conclusion
Namada and Celestia, each potent in their own domain, could potentially offer an amalgam of features that alleviate the concerns around privacy and data availability in the blockchain ecosystem. While no formal collaboration is underway, the synergies between these two platforms open up exciting avenues for future development.
In the end, Namada aims to provide "Privacy as a Service," offering robust privacy guarantees for users who wish to interact with platforms like Celestia.
Namada is a Proof-of-Stake Layer 1 blockchain protocol that delivers multichain, asset-agnostic privacy. Utilizing advanced zk-SNARKs technology, Namada facilitates indistinguishable transactions for various assets in its unique Multi-Asset Shielded Pool (MASP). Developed by Heliax in the Anoma ecosystem, Namada is working toward a future where digital asset privacy becomes the norm, not the exception.