  Driven by the aspiration to establish a decentralized digital economy, Web
3.0 is emerging as the fundamental technology for digital transformation.
Incorporating the promising sixth-generation (6G) technology with large
bandwidth and space-air-ground integrated coverage, 6G-based Web 3.0 holds
great potential in empowering users with enhanced data control and facilitating
secure peer-to-peer transactions, especially in consumer electronics, through
the utilization of blockchain technologies. However, 6G-based Web 3.0 is still
in its infancy, such as ensuring block freshness and optimizing block
propagation to improve blockchain performance. In this paper, we develop a
freshness-aware block propagation optimization framework for 6G-based Web 3.0.
We first propose a novel metric called Age of Block Information (AoBI) based on
the concept of age of information to quantify block freshness. To make block
propagation optimization tractable, we classify miners into five different
states and propose a block propagation model for public blockchains inspired by
epidemic models. Moreover, considering that the miners are bounded rational, we
propose an incentive mechanism based on the evolutionary game for block
propagation to improve block propagation efficiency. Numerical results
demonstrate that compared with other block propagation mechanisms, the proposed
scheme has a higher block forwarding probability, which improves block
propagation efficiency.
