Addressing the Post-Quantum signature bloat problem without sacrificing consumer node validation

The long-term threat of Shor’s algorithm against elliptic curves (secp256k1) is well understood, but the network-level bottleneck of transitioning Bitcoin to post-quantum cryptography doesn't get enough attention: raw byte overhead.

Under NIST FIPS 204 (ML-DSA-65 / Dilithium), a single post-quantum signature is roughly 3,300 bytes. Compare that to our current 64-byte Schnorr signatures.

If Bitcoin eventually soft-forks or hard-forks to introduce native post-quantum signature verification, naive wire gossip would cause immediate issues:

1. P2P Head-of-Line Blocking: A standard 4 MB block would hold only a fraction of today's transaction count, and mempool gossip would overwhelm low-bandwidth peers.
2. Loss of Home Verification: The primary ethos of Bitcoin is that anyone can run a node on commodity hardware (like a Raspberry Pi or older PC). Storing and continually streaming megabytes of raw lattice signatures across the p2p gossip layer threatens that decentralization.

A Viable Architectural Path: Instead of forcing every home node to ingest and retain full multi-kilobyte signature payloads forever, the validation pipeline can be decoupled across network topology:

• Bounded Validator/Consensus Tier: A bounded committee tier of dedicated, high-spec nodes processes the active BFT consensus rounds and bears the bandwidth load of verifying full ML-DSA-65 signatures during block assembly.
• Succinct Light Verification for the Rest: Ordinary peer nodes do not need to gossip or indefinitely archive the raw ~3.3 KB signature envelopes. Instead, they verify state transitions through deterministic state commitments and cryptographic hashing (e.g., SHA3-256 roots).

By decoupling the raw multi-kilobyte cryptographic verification at ingest from long-term state commitment, the network achieves quantum resistance against future attacks without forcing home node runners off the network due to disk bloat and p2p bandwidth choke.

Curious how Bitcoin core developers and node runners view the trade-offs between topology-based payload segregation versus waiting on recursive proof aggregation when the quantum transition timeline eventually tightens.