PANews reported on December 9th that, according to CoinDesk, Shielded Labs has proposed a new proposal to create a dynamic fee market for Zcash to address rising transaction costs and network congestion. The proposal suggests abandoning Zcash's static fee model—initially 10,000 "zatoshi," later reduced to 1,000. While this model worked when demand was low, it ultimately triggered a "sandblast" of spam transactions, causing wallet congestion and on-chain transaction blockage. Previously, the ZIP-317 proposal used an operation-based ledger, which addressed abuse issues, but fees remained predictable and low, unable to adjust based on usage.

The latest proposal introduces a simple, stateless, dynamic fee design built around "comparables." This involves using the median fee of each operation observed over the past 50 blocks as a benchmark, and adding synthetic transactions to simulate persistent congestion. The median fee will become the standard fee, divided into intervals raised to powers of ten to reduce chainability and prevent the leakage of user information. Under stress, a priority channel will be temporarily opened with a fee 10 times the standard fee, allowing users to compete for block space without redesigning the protocol. The system is planned for phased rollout. Initially, it will be monitored off-chain, then implemented as a wallet policy, and only after approval will it be rolled out as a simple consensus change, setting expiration height limits and power-of-ten fee rules. This avoids the complexity and fork risks of mechanisms like EIP-1559 while maintaining Zcash's privacy constraints. Other proposed ideas include using mining difficulty as a long-term heuristic of USD-denominated fees, adjusting prices based on mempool pressure.