Avail employs KZG commitments and Data Availability Sampling (DAS) to ensure efficient and secure data availability.
KZG commitments benefit Zero Knowledge-based blockchains, reducing memory, bandwidth, and storage requirements. The initialism KZG comes from the researchers Kate, Zaverucha, and Goldberg who created the commitment scheme. Their contributions to the field of cryptography led us to name the “Kate” testnet, in honor of these commitments and the researchers who devised them. These commitments not only fast-track block acceptance but also eliminate the usual waiting periods required in fraud-proof-based data availability systems.
Here is a really good post about KZG commitments in detail.
DAS allows light clients to provide trust-minimized security. Avail light clients, like other light clients, only download the headers of the blockchain. However, they additionally perform data availability sampling: a technique that randomly samples small sections of the block data and verifies they are correct.
When combined with erasure coding and KZG polynomial commitments, Avail clients are able to provide strong (nearly 100%) guarantees of availability without relying on fraud proofs, and with only a small constant number of queries.