The Stellar Development Foundation has introduced its Quantum Preparedness Plan, a phased roadmap to move the Stellar Network toward quantum-safe cryptography before the threat becomes operational. The plan targets readiness work through 2027 and is designed to let accounts add quantum-safe authorization while keeping the same Stellar address, balance and transaction history.
The roadmap responds to a specific cryptographic risk: sufficiently powerful quantum computers could eventually break Ed25519, the elliptic-curve signature scheme currently used across Stellar accounts and validator authentication. SDF is framing the transition as a planned infrastructure migration rather than an emergency hard fork after the threat arrives.
Stellar Separates Account Identity From Signing Keys
Stellar’s key advantage is that account identity and signing keys are not the same object. On Stellar, an account can rotate or add signing authority through existing account controls without moving funds to a new address. That architecture gives the network a cleaner migration path than systems where the address itself is directly tied to a single public key.
Stage 1, targeted for 2026, brings post-quantum signature verification into Soroban as native host functions. The first supported schemes are expected to include ML-DSA-44 and ML-DSA-65, giving contract accounts and smart wallets a way to enforce quantum-safe authentication before classic accounts receive protocol-level signer support. Enterprise wallets could begin moving to quantum-safe contract accounts during this first phase.
Stage 2, planned for 2027, would introduce quantum-safe signer types directly into the core protocol through a Core Advancement Proposal. Existing Stellar accounts would be able to add a post-quantum signer alongside their Ed25519 signer, preserving account continuity while wallets, SDKs, anchors and custodians update their systems. The goal is opt-in migration before any forced cutoff is considered.
Ed25519 Deprecation Depends on Threat Readiness
Stage 3 covers the eventual deprecation of Ed25519 for new transaction authorization, but SDF has not assigned a fixed ledger height or activation date. The timing will depend on quantum-computing progress and ecosystem readiness, because a premature cutoff could disrupt dormant accounts, custodial systems and payment infrastructure.
The dormant-account issue is one of the most difficult governance questions in the plan. Stellar has accounts whose holders may be unreachable, and forced deprecation could require either recovery mechanisms or acceptance that some accounts become permanently locked. SDF said that decision will require community design discussion rather than a unilateral technical switch.
The plan also separates two risks: account takeover and network integrity. Account takeover is the harder problem because account public keys are directly exposed in Stellar addresses, while validator-signature migration is a smaller but still serious consensus-layer coordination task. QPP focuses first on protecting accounts, then on broader protocol migration.
The cryptographic timeline is becoming more urgent. SDF cited early 2026 research estimating that breaking 256-bit elliptic curves would require 1,193 logical qubits, a lower threshold than earlier models suggested. Combined with NIST’s finalized post-quantum standards and industry migration planning, Stellar is treating quantum resistance as an infrastructure deadline, not a distant research topic.
The plan does not yet solve every post-quantum challenge. SDF noted that pairing-based zero-knowledge systems, including SNARKs built on curves such as BN254 and BLS12-381, still lack a simple post-quantum replacement with comparable performance. Quantum-safe signatures are the first migration track, not the entire cryptographic endgame.
Stellar has published a formal quantum-readiness roadmap built around Soroban host functions in 2026, protocol-level signer support in 2027 and later Ed25519 deprecation once threat conditions justify it. The next milestones are technical specifications, community discussion on dormant accounts and formal protocol proposals for quantum-safe signer support.