Walrus: Rethinking Decentralized Storage
Resilient Blob Storage
In the ever-expanding universe of blockchain infrastructure, Mysten Labs—the team behind the high-performance Sui blockchain—has launched one of the most ambitious decentralized storage protocols yet: Walrus. It aims to redefine the way decentralized applications interact with data itself: how it’s stored, accessed, verified, and priced.
While most blockchains struggle to handle large volumes of unstructured data, Walrus is engineered from the ground up as a decentralized blob store—designed to be fast, cheap, verifiable, and resilient. It brings together advanced erasure coding, tight coordination with the Sui blockchain, and a clean separation of roles across users, storage nodes, aggregators, and publishers. Together, these components form a robust, permissionless protocol that supports everything from AI datasets and ZK-proofs to media-heavy dApps and blockchain history.
This article explores the architecture and features of Walrus in-depth, walking you through how it works, what makes it different, and why it’s a foundational primitive for Web3 builders.
The Problem Walrus Solves
Traditional decentralized storage networks enable you to store files off-chain. But they rarely guarantee that those files are available when you need them, or that someone else hasn’t tampered with the content. For mission-critical apps—think AI agents, rollups, decentralized frontends—this is unacceptable. These apps need to:
Store large binary data (blobs) like videos, models, snapshots
Access it reliably, even if part of the network fails
Verify availability without needing the whole file
Do all this cheaply and programmatically
Walrus addresses these needs by introducing a verifiable, resilient blob storage layer that runs independently but coordinates tightly with the Sui blockchain.
What is a Blob?
The term “blob” stands for Binary Large Object. It refers to data that can’t easily be structured into tables or simple key-value pairs: images, sound files, AI model weights, blockchain snapshots, or JavaScript files.
Walrus is purpose-built to store and retrieve these kinds of unstructured data in a decentralized way. Crucially, it also lets users and smart contracts verify whether a blob exists and is available for use—without needing to download it in full.
The User Journey: How a Blob is Stored and Verified
To understand Walrus, let’s walk through the steps that happen when a user wants to store a blob:
Upload: A user (or publisher) submits the blob to the Walrus network using a CLI, SDK, or Web2 interface.
Encoding: The blob is split into slivers using an erasure coding algorithm called Red Stuff, which encodes the file into smaller pieces spread across many storage nodes.
Distribution: Each sliver is assigned to a storage node within a given storage epoch. These nodes commit to storing and serving their assigned slivers.
Proof of Availability: Once the nodes acknowledge receipt, the user collects signed attestations and combines them into an availability certificate.
On-Chain Attestation: The user uploads the certificate to the Sui blockchain, where it becomes a permanent record of the blob’s availability.
Verification: Anyone (including smart contracts or light clients) can now verify the blob’s availability on-chain by referencing this certificate.
This mechanism allows Walrus to guarantee that blobs are retrievable—even if two-thirds of the storage network goes offline.
Under the Hood: Red Stuff, Slivers, and Shards
At the heart of Walrus’s efficiency is its erasure coding protocol, Red Stuff. It solves a fundamental tradeoff in decentralized storage between replication cost and data resilience.
Rather than duplicating entire blobs across nodes (which would be prohibitively expensive), Red Stuff breaks each blob into slivers. These slivers are then grouped into shards, which are stored across different storage nodes.
Red Stuff enables:
Self-healing recovery when nodes go down
Low bandwidth requirements for repair
Verifiability in asynchronous networks, which prevents malicious nodes from exploiting network delays#WALRUS $WAL @Walrus 🦭/acc
