In this paper, we present a new randomized synchronous BFT paradigm with optimal resilience, expected O(1) time, and amortized O(n) message per block proposal. The paradigm reduces BFT to a new variant of multi-valued agreement. To instantiate our BFT protocol, we also provide a binary agreement protocol and a multi-valued agreement protocol with fewer steps than those of Katz & Koo (CRYPTO 06) and ADDNR (FC 21).

In this paper, we present a new primitive called threshold encryption with controlled authorization, designed for permissioned blockchains. It allows a writer to encrypt messages on the blockchain and subsequently authorize a subset of readers to decrypt them, enabling fine-grained access control.