Stellar has officially launched the Quantum Preparedness Plan (QPP), a network-wide initiative to transition the blockchain toward quantum-safe cryptography. According to Build on Stellar, the roadmap addresses the looming threat of quantum computers breaking current elliptic curve cryptography (ECC) that secures most blockchains, and sets phased upgrades through 2027. Users will keep their existing account addresses and transaction history throughout the migration.
Quantum Threats Are Already Clocking In
Stellar warned that quantum computers could eventually break ECC, which also underlies TLS, SSH, and code-signing systems — not just digital assets. Recent research by INRIA shows that breaking 256-bit elliptic curves requires fewer quantum resources than previously estimated. Meanwhile, NIST has updated its cryptographic standards, and Google set an internal post-quantum readiness target of 2029.
Two Core Risks: Validator Forgery and Account Takeover
Stellar identified two primary threats. First, validator signature forgery could compromise network integrity. Second — and more critical — account takeovers via compromised Ed25519 public keys. Unlike many blockchains, Stellar separates account identity from signing keys, allowing users to rotate signing credentials without changing addresses. This design eliminates the need to transfer balances to new addresses during migration. Users will simply add quantum-safe signers, adjust weight thresholds, and later remove legacy Ed25519 signers. However, no quantum-safe signer types exist on the protocol yet, so QPP focuses on creating these signer types and the supporting verification infrastructure.
2026: Soroban Contract Accounts Go First
The first phase begins in 2026 with Soroban smart contract accounts. Stellar plans to support ML-DSA-44 and ML-DSA-65, two signature standards finalized by NIST. This gives developers an early migration path.
2027: Protocol Upgrade Reaches All Accounts
The second phase is a 2027 protocol upgrade that introduces quantum-safe signers directly to traditional Stellar accounts. Users add new signer types through standard account operations while keeping their original addresses. Stellar has not yet decided on a cutoff date for phasing out Ed25519 signatures, leaving it for community discussion. Future talks will cover dormant accounts, recovery mechanisms, validators, wallets, custodians, SDK maintainers, and Soroban developers as technical specs move forward.
Stellar's quantum preparedness plan sets a tangible timeline for the broader crypto industry. As NIST standards mature and quantum computing accelerates, laying the groundwork for post-quantum cryptography is no longer a choice — it's a necessity.