From ECDSA to Post-Quantum Signatures: Practical Lessons from Migrating Wallet-Based Transaction PKI

Many post-quantum migration discussions focus on TLS, certificates, and enterprise PKI. A different but increasingly important case is wallet-based transaction infrastructure, where long-lived accounts, public-key exposure, signature verification, hardware constraints, recovery flows, and user experience all interact with cryptographic migration.

This session presents practical lessons from designing and implementing a migration path from ECDSA-based transaction signing toward post-quantum signatures in an EVM-like blockchain environment. It focuses on architecture and engineering trade-offs rather than product claims: key generation and storage, address derivation, signature-size impact, transaction encoding, verification cost, backward compatibility, testnet strategy, smart-account and vault-based migration models, and how to avoid creating unsafe hybrid systems that merely add complexity without reducing risk.

The talk also examines the relationship between blockchain wallet infrastructure and traditional PKI concepts: identity binding, certificate-like assertions, key lifecycle management, recovery, revocation, policy enforcement, auditability, and hardware-backed key protection. Special attention is given to migration patterns that allow existing assets or accounts to gain post-quantum authorization controls without assuming an overnight replacement of legacy systems.

Attendees will leave with a concrete checklist for evaluating post-quantum readiness in transaction-signing systems: where classical signatures remain a dependency, which components need cryptographic agility, what must be measured before migration, and which design decisions can create operational or security risks during the transition.