Crate komodo

Komodo: Cryptographically-proven Erasure Coding

Komodo provides an easy-to-use Rust library and ecosystem that is composed of two main parts:

• support for FEC encoding and decoding with the fec submodule
• support for proving and verifying shards of encoded data with the semi_avid, kzg* and aplonk* submodules

Note

modules marked with an *, e.g. kzg*, are hidden behind a Cargo feature with the same name

Other submodules define several fundamental building blocks to Komodo, but which are not mandatory to explore to understand the protocols.

Example

Let’s explain with a very simple example how things operate with Komodo.

Note

the following example uses some syntax of Rust but is NOT valid Rust code and omits a lot of details for both Rust and Komodo

1. choose an encoding matrix to encode the input data

let encoding_mat = Matrix::random(k, n, rng);

2. encode the data and build encoded shards

let shards = fec::encode(bytes, encoding_mat);

3. attach a cryptographic proof to all the shards and get a proven block

let blocks = prove(bytes, k);

4. verify each block individually

for block in blocks {
    assert!(verify(block));
}

5. decode the original data with any subset of k blocks

assert_eq!(bytes, fec::decode(blocks[0..k]));

Modules

algebra

Manipulate finite field elements

aplonk

aPlonK: an extension of KZG+ where commits are folded into one

error

Komodo-specific errors

fec

a module to encode, recode and decode shards of data with FEC methods.

kzg

KZG+: the multipolynomial and non-interactive extension of KZG

semi_avid

Semi-AVID: a proving scheme suited for an information dispersal context

zk

a replacement of Arkworks’ KZG10 module