Walrus splits its design into a data plane (storage nodes) and a control plane (the Sui blockchain). Storage nodes do the heavy lifting of encoding, storing, and serving data fragments (slivers). Meanwhile, Sui handles all metadata and coordination via Move smart contracts. For each file upload, Walrus assigns it a unique on-chain object: this object on Sui contains the file’s ID, size, cryptographic commitments, and the payment/stake information. Because Sui is highly parallel and low-cost, it can track hundreds of such storage transactions at once without bottlenecks.
At its core Walrus uses Red Stuff, a two-dimensional erasure-coding protocol designed for asynchronous networks. When a client uploads a blob, Red Stuff transforms it into a matrix of data fragments (slivers). Some slivers are “primary” (direct pieces of the data) and others are “secondary” (redundant XOR-encoded backups). These slivers are spread across a committee of storage nodes chosen for that epoch. Even if up to two-thirds of nodes fail or go offline, the remaining slivers can reconstruct the full file thanks to this encoding.
Walrus uses a Delegated Proof-of-Stake (dPoS) model for security: storage node operators must stake WAL tokens to join, and holders can delegate their stake to trusted operators. Misbehaving or offline nodes can be slashed (their stake burned). Nodes earn WAL rewards from user fees and protocol subsidies for honestly storing data.
All storage economics like staking, delegation, fee distribution are enforced by Move smart contracts on Sui.
