AnyTrust and the Data Availability Committee

Sanko's initial Data Availability Cohort

Sanko achieves subcent transaction fees in part by significantly reducing the costs associated with posting transaction data – the largest cost component for most optimistic rollups.

Sanko adopts a minimal trust assumption in the form of the Data Availability Committee – a cohort of validators responsible for storing transaction data and providing it on demand. Rather than posting full data blocks, Committee members post Data Availability Certificates (DACerts) containing the hash of a data block, an expiration time, and proof that a sufficient number of Committee members have signed the pair attesting to the validity of the block.

Sanko assumes that at least two Committee members are honest; thus, if the Committee has N members and N – 1 promise to provide access to transaction data, at least one of the promisers will provide data as needed to ensure the proper functioning of the chain.