It was a great time at Financial Cryptography last week; truly a privilege for Soundness to support and sponsor such an important event for the crypto and security community. Last month, we shared that two papers co-authored by the Soundness team were accepted to FC.
https://x.com/SoundnessLabs/status/2021242498253980087
One of them focused on post-quantum readiness for EdDSA chains, and we were excited to finally present the full story, live demos, and practical results to the community. This is a joing work with amazing researchers at Mysten Labs.
Below is a short slide-by-slide walkthrough of the talk and the core strategy behind what we are building at Soundness.
Quantum security is no longer a distant research topic. It is becoming a real infrastructure challenge for blockchains in different aspects.
Millions of dormant accounts cannot react to migration calls. Forcing users to rotate keys, change addresses, or transfer assets creates massive operational risk and cost at global scale.
So what is the ideal migration path? We believe the only realistic upgrade must be backward compatible. Users should not need to change addresses or touch their assets. Even exposed public keys and sleeping accounts should be protectable.
This is where EdDSA-based chains show a structural advantage.
Unlike ECDSA, EdDSA derives signing keys deterministically from a seed. This design decision, originally made for simplicity and safety, quietly creates a natural hook for post-quantum migration.
Sometimes standards hide small gifts for the future.
The core trick is elegant.
Instead of treating the scalar as the main secret, we treat the EdDSA seed as the root of authority. A user can prove knowledge of this seed inside a zero-knowledge proof, without revealing any elliptic-curve secret. This proof can authorize a new post-quantum signature key. No address change. No asset transfer. Essentially zero user friction. Migration becomes a one-time certification step.
A proof binds the legacy account to a new PQ public key. After on-chain attestation, the account can operate fully with post-quantum signatures. If PQ schemes evolve in the future, the certification can simply be regenerated.
We also formalize a dual-mode security model.
Classical signatures remain backward compatible, while the PQ mode provides forward security even if classical assumptions break. This enables a gradual and realistic transition strategy for real networks.
Importantly, this is not only a theoretical result.
At Soundness we are actively shipping the migration product to our ICP and early partners, focusing on real deployment constraints such as browser-side proving, MPC account compatibility, enterprise compliance workflows, and scalable on-chain verification.
The work received very positive feedback from both academic researchers and industry builders during FC and in follow-up discussions. Many teams recognize that seamless migration, especially for institutional custody and MPC wallets before chains to the full migration, is one of the hardest unsolved challenges in the quantum transition. This validation gives us strong confidence that Soundness is well positioned to have a meaningful impact on the future post-quantum world. We are excited for what comes next.
Lets make onchain assets quantum secure today. 🐬
