Overview
The post explores PQ-Verkle—a variant of Verkle trees potentially adapted for post-quantum (PQ) security—and its role in addressing Ethereum’s ever-growing state size. It frames the discussion by asking: What problems does Verkle solve, what are its key advantages, what do critics say, and can we “harden” it for a post-quantum world?
The Problem: Ethereum’s Growing State
State Bloat and Hardware Demands:Ethereum’s state is continuously expanding, which increases storage and I/O requirements for nodes. This rise forces full-nodes to manage large witness sizes (proofs of state), making it costly in terms of disk access and bandwidth.
Statelessness as a Goal:The ideal is to enable nodes to verify blocks without storing the entire state locally. Verkle trees aim to reduce the witness size dramatically, lowering the barrier for participation and improving network efficiency.
What Makes Verkle Trees Attractive?
Efficient Storage Proofs:Reduced Data Needs:Verkle trees use vector commitments (VCs) that compress proofs. Instead of including multiple sibling nodes (as in Merkle trees), only one commitment per tree level is needed.
Scaling with Arity:A higher arity leads to a shallower tree, resulting in fewer VC openings per proof. This efficiency becomes more pronounced as more leaves (state entries) are proven simultaneously.