Key Highlights
- The primary risk from quantum computers is the potential exposure of private keys, which could enable attackers to take control of accounts.
- In 2026, Stellar will begin supporting post-quantum signature verification for Soroban smart contracts using NIST-approved algorithms.
- XLM holders will not need to change wallet addresses or move funds.
Stellar’s newly announced Quantum Preparedness Plan (QPP) has put the spotlight squarely on XLM holders and the practical steps they will need to take to protect their assets. While the initiative is a forward-looking security upgrade rather than an emergency response, it raises an immediate question for millions of users: when and how will their wallets need to be upgraded to support quantum-safe cryptography?
According to Stellar, the core issue stems from the looming threat of quantum computers. Advanced quantum machines running Shor’s algorithm could eventually break today’s widely used elliptic curve cryptography, including the Ed25519 signature scheme that powers Stellar and most other blockchains.
Recent research has accelerated timelines. Scientists at INRIA have significantly reduced the number of logical qubits needed to crack 256-bit elliptic curves, and NIST now estimates relevant risks could emerge by 2029 or earlier. With major tech companies like Google targeting post-quantum readiness around the same period, blockchain networks are racing to adapt.
Account takeover remains the biggest challenge
For XLM holders, the biggest personal risk is account takeover. A sufficiently powerful quantum computer could theoretically derive private keys from public keys, allowing attackers to drain accounts. Validator signature compromise could also threaten network consensus, but individual account security is the more pressing concern for everyday users, especially given the high number of dormant accounts on the network.
Stellar’s account model separates the account identity, the familiar “G…” address, from the actual signing keys. This architectural advantage means users do not need to migrate funds or change addresses. Instead, they will be able to add quantum-resistant signers to their existing accounts through familiar operations.
Stellar rolls out staged phases for users
According to the QPP roadmap, changes for holders begin in 2026. Stage 1 focuses on Soroban smart contracts, adding support for post-quantum signature verification using NIST-standard algorithms such as ML-DSA-44 and ML-DSA-65. Enterprise and advanced users can start experimenting with quantum-safe contract accounts during this phase.
The more significant milestone arrives in 2027. Stage 2 will introduce native quantum-safe signer types for classic accounts via a Core Advancement Proposal. By the end of that year, every Stellar account should be able to support quantum-resistant signatures alongside existing Ed25519 keys. This dual-signer approach allows a gradual transition without disrupting transaction history or addresses.
Stage 3 will eventually deprecate Ed25519 for new transactions, though the exact timeline remains flexible based on real-world quantum progress and ecosystem readiness.
Users will likely need to approve adding quantum-safe keys through their wallet’s interface, a process expected to resemble today’s multi-signature management but with new cryptographic options.
Timeline for XLM Holders
| Timeline | What Stellar Plans | What It Means for XLM Holders |
|---|---|---|
| 2026 | Quantum-safe signature verification through Soroban contract accounts | Enterprise and advanced wallets may start testing quantum-safe signing |
| 2027 | Native quantum-safe signers for classic Stellar accounts | Regular XLM holders may get wallet-level upgrade options |
| After 2027 | Possible Ed25519 deprecation | Users who do not upgrade may face restrictions depending on final community decisions |
Do XLM Holders Need to Act Now?
For now, regular XLM holders do not appear to need immediate action.
Stellar’s roadmap is still in the preparation phase, and the broad user upgrade path is expected in 2027. The key thing for users is to watch for official wallet updates, exchange notices and Stellar ecosystem announcements.
XLM holders should also avoid any third-party link claiming to offer an urgent “quantum wallet upgrade” before official support is released.
The main takeaway is that Stellar’s plan may spare users from moving funds to new addresses. But it does not remove the need for wallet, exchange and custodian upgrades.
Users advised to be prepared instead panic
The plan is not without hurdles. Zero-knowledge proof systems on Stellar still require additional research due to their reliance on vulnerable curves. Broader success depends on coordinated efforts across developers, validators, and service providers.
For XLM holders, the message is one of preparation rather than panic. The transition appears designed to be as seamless as possible thanks to Stellar’s flexible account structure. However, inaction could leave assets vulnerable in the long term. Users should monitor official SDF channels, keep wallets updated, and prepare to add quantum-safe signers once the features become available.
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