Walrus Glossary
To make communication as clear and efficient as possible, we make sure to use a single term for every Walrus entity/concept and do not use any synonyms. The following table lists various concepts, their canonical name, and how they relate to or differ from other terms.
Italicized terms in the description indicate other specific Walrus terms contained in the table.
| Approved name | Description |
|---|---|
| 2D encoding | encoding scheme used in RedStuff where each blob is encoded in two dimensions—primary and secondary—to ensure robust recovery and redundancy |
| aggregator | service that reconstructs blobs by interacting with SNs and exposes a simple HTTP GET endpoint to end users |
| availability period | the period specified in storage epochs for which a blob is certified to be available on Walrus |
| blob | single unstructured data object stored on Walrus |
| blob ID | cryptographic ID computed from a blob’s slivers |
| blob metadata | metadata of one blob; in particular, this contains a hash per shard to enable the authentication of slivers and recovery symbols |
| cache | an aggregator with additional caching capabilities |
| certificate of availability (CoA) | a blob ID with signatures of SNs holding at least shards in a specific epoch |
| client | entity interacting directly with the SNs; this can be an aggregator/cache, a publisher, or an end user |
| deletable blob | blob which can be deleted by its owner at any time to be able to reuse the storage resource |
| expiry | the end epoch at which a blob is no longer available and can be deleted; the end epoch is always exclusive |
| (end) user | any entity/person that wants to store or read blobs on/from Walrus; can act as a Walrus client itself or use the simple interface exposed by publishers and caches |
| FROST | the smallest unit of WAL (similar to MIST for SUI); 1 WAL is equal to 1 billion (1000000000) FROST |
| inconsistency certificate | an aggregated signature from 2/3 of SNs (weighted by their number of shards) that they have seen and stored an inconsistency proof for a blob ID |
| inconsistency proof | set of several recovery symbols with their Merkle proofs such that the decoded sliver does not match the corresponding hash; this proves an incorrect/inconsistent encoding by the client |
| member | an SN that is part of a committee at some epoch |
| permanent blob | blob which cannot be deleted by its owner and is guaranteed to be available until at least its expiry epoch (assuming it is valid) |
| point of availability (PoA) | point in time when a CoA is submitted to Sui and the corresponding blob is guaranteed to be available until its expiration |
| publisher | service interacting with Sui and the SNs to store blobs on Walrus; offers a simple HTTP POST endpoint to end users |
| reconstruction (of a blob) | decoding of the primary slivers to obtain the blob; includes re-encoding the blob and checking the Merkle proofs |
| recovery | process of an SN recovering one or multiple blobs, slivers, or full shards by obtaining recovery symbols from other SNs |
| RedStuff | our erasure-encoding approach, which uses two different encodings (primary and secondary) to enable shard recovery; details are available in the whitepaper |
| shard | (disjoint) subset of erasure-encoded data of all blobs; at every point in time, a shard is assigned to and stored on a single SN |
| sliver | erasure-encoded data of one shard corresponding to a single blob for one of the two encodings; this contains several erasure-encoded symbols of that blob but not the blob metadata |
| sliver pair | the combination of a shard’s primary and secondary sliver |
| staker | entity that locks (stakes) WAL tokens to support the network's integrity and participate in the selection or validation of storage nodes and committees. |
| storage challenge | cryptographic proof mechanism where SNs periodically verify each other’s storage of assigned shards by issuing random challenges during storage attestation. |
| storage attestation | process where SNs exchange challenges and responses to demonstrate that they are storing their currently assigned shards |
| storage committee | the set of SNs for a storage epoch, including metadata about the shards they are responsible for and other metadata |
| storage epoch | the epoch for Walrus as distinct to the epoch for Sui; the epoch duration for Mainnet is two weeks |
| storage node (SN) | entity storing data for Walrus; holds one or several shards |
| WAL | the native Token of Walrus |