Authors:
Antoine Stevan
1
;
Thomas Lavaur
1
;
2
;
Jérôme Lacan
1
;
Jonathan Detchart
1
and
Tanguy Pérennou
1
Affiliations:
1
ISAE-SUPAERO, Toulouse, France
;
2
University Toulouse III Paul Sabatier, Toulouse, France
Keyword(s):
Erasure Code, Polynomial Commitment, Distributed Storage.
Abstract:
Erasure coding is a common tool that improves the dependability of distributed storage systems. Basically,
to decode data that has been encoded from k source shards into n output shards with an erasure code, a node
of the network must download at least k shards and launch the decoding process. However, if one of the
shards is intentionally or accidentally modified, the decoding process will reconstruct invalid data. To allow
the verification of each shard independently without running the decoding for the whole data, the encoder
can add a cryptographic proof to each output shard which certifies its validity. In this paper, we focus on the
following commitment-based schemes: KZG+, aPlonK-PC and Semi-AVID-PC. These schemes perform
polynomial evaluations in the same way as a Reed-Solomon encoding process. Still, such commitment-based
schemes may introduce huge computation times as well as large storage space needs. This paper compares
their performance to help designers of distributed s
torage systems identify the optimal proof depending on
constraints like data size, information dispersal and frequency of proof verification against proof generation.
We show that in most cases Semi-AVID-PC is the optimal solution, except when the input files and the
required amount of verifications are large, where aPlonK-PC is optimal.
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