Post-Quantum Cryptography for Frontier

[hayotensor]

I'd like to open a discussion around post-quantum cryptography (PQC) support in Frontier / the Polkadot EVM stack. With Ethereum explicitly considering PQC in its long-term roadmap, it seems reasonable for us to begin evaluating what this means for Frontier and Substrate-based EVM chains.

Ethereum references:

• https://pq.ethereum.org/
• https://strawmap.org/

Ethereum is estimating to start the transition in 2027, and I'm sure you already know that Google is estimating 2029 for quantum computing viability. While this isn't imminent, I wanted to start the discussion since I don't see any info about this here.

I'm sure the transition would require waiting for Ethereum to start and implement their logic in frontier but:

• Does transitioning to PQ require actions on the Polkadot side?
• What else needs to take place?

[sueun-dev]

hey, good topic. this doesnt get enough attention in the Substrate EVM space.

on whether PQ requires actions on the polkadot side - yes but Substrate actually has a structural advantage here. forkless runtime upgrades + pluggable crypto primitives means adding new PQC signature schemes at the runtime level is way cleaner than doing it on Ethereum L1. parachains can swap in new key types without a hard fork.

the trickier part is Frontier specifically since its whole job is EVM compat. it'll need to mirror whatever precompiles and opcode changes Ethereum lands for PQC. so theres definitely a dependency on Ethereum finalizing their approach first, like you said.

for what else needs to happen, a few things come to mind:

1. account abstraction is probably the most realistic near-term path. EIP-4337/7702 style AA lets accounts use arbitrary signature verification, so you can have PQC-secured smart contract wallets without core protocol changes. making sure Frontier has solid AA support is probably step one

2. new precompiles for PQC sig verification will come eventually (NIST finalized ML-DSA/ML-KEM standards). Frontier will need matching implementations. gas pricing for these will be interesting since PQC sigs are way larger than ECDSA - we're talking ~2.4KB for dilithium vs 65 bytes

3. that signature size difference has real implications for calldata costs and block space. Frontier chains on Substrate can potentially handle this better with more flexible fee structures than mainnet

4. Ethereum's been planning for a "quantum emergency" scenario with account migration paths. Frontier would need something similar

for the 2027 timeline, i'd expect Ethereum to start with optional PQC through account abstraction first, then native protocol changes later. Frontier can start preparing now by ensuring full AA support and tracking the PQC precompile EIPs as they get proposed.

would be good to see a tracking issue here once Ethereum's approach solidifies more. lmk if you want to dig into any specific part of this

[hayotensor]

Are you a dev on frontier or is this AI?

[sueun-dev]

Im engineer, no worries!

I just have interest in this proejct and then i am studying it