Sui Plans Quantum-Safe Signatures Without Moving Users’ Funds
Sui is preparing quantum-safe accounts and vaults, with a migration design that would allow users to change the cryptography protecting their account without moving assets to a new address.
Key Takeaways
- Sui plans two NIST-standardized post-quantum signature systems for different types of accounts.
- Existing users should be able to switch to a quantum-safe signer without moving assets to a new address.
- The same recovery phrase can generate the new key through a separate derivation path.
- Post-quantum signatures are substantially larger, increasing transaction data requirements.
- The upgrade is still being audited and tested; Sui is not fully quantum-resistant today.
Sui has outlined how it plans to introduce post-quantum signatures without forcing users through one of the most difficult parts of a blockchain security upgrade: moving everything they own to a new account.
The network plans to support ML-DSA-65, standardized by NIST under FIPS 204, for normal accounts and SLH-DSA-SHA2-128s under FIPS 205 for higher-value vaults built with Move smart contracts. Both are designed to resist attacks from the type of large-scale quantum computers that could eventually threaten the elliptic-curve signatures widely used across crypto today.
The Account Can Stay Even When the Key Changes
Normally, replacing the cryptography behind a blockchain account can require users to create a new address and transfer tokens, NFTs and other assets. Applications and contracts tied to the old address may also need to adjust.
Sui’s existing Address Aliases system provides a way around that problem. An account can maintain a set of authorized aliases, allowing another signer to authenticate transactions on behalf of the original address.
A new signer can be added to that authorized set and eventually become the only signer allowed to approve transactions, while the original address continues to appear as the sender.
When ML-DSA accounts become available, Sui says an existing account will be able to authorize a post-quantum signer while retaining the same address. That is particularly useful for accounts already connected to smart contracts, identities or other applications where changing an address creates more work than simply transferring SUI.
The recovery process is also designed to remain familiar. An ML-DSA-65 key can be derived from a user’s existing recovery phrase through a new derivation path rather than requiring an entirely different backup method.
An authorized alias has full authority over the account. Sui’s documentation warns that adding one effectively gives that signer control over the assets owned by the address, meaning wallet software will need to make the migration process difficult to misuse or misunderstand.
Why Sui Is Using Two Different Quantum-Safe Systems
| Account Type | NIST Standard | Cryptography Basis | Signature Size |
|---|---|---|---|
| Normal Accounts | ML-DSA-65 (FIPS 204) | Lattice-based (Category 3) | 3,309 bytes |
| High-Value Vaults | SLH-DSA-SHA2-128s (FIPS 205) | Hash-based (Category 1) | 7,856 bytes |
Sui is not relying on one post-quantum design for every use case.
ML-DSA-65 is lattice-based and intended for normal transaction signing. It corresponds to NIST security Category 3, providing more security margin than the smaller ML-DSA-44 configuration while remaining practical enough for frequent verification.
Sui also pointed to the recent AI-assisted discovery of a weakness in HAWK, another post-quantum signature candidate. The finding did not compromise ML-DSA, but it showed how quickly automated cryptanalysis can challenge designs that have already undergone extensive human review. Our recent analysis examined the HAWK weakness and what AI-assisted cryptanalysis could mean for post-quantum standards.
For higher-value vaults, Sui plans to support SLH-DSA-SHA2-128s through Move smart contracts.
SLH-DSA-SHA2-128s is a Category 1 configuration, below ML-DSA-65’s Category 3 rating. Sui’s rationale instead comes from its hash-based design, which provides an alternative to ML-DSA’s lattice assumptions and reduces dependence on a single cryptographic foundation.
A weakness discovered in one family would not automatically undermine the other, while the smart-contract implementation gives vault developers more flexibility to replace the scheme later if needed.
The cost is size. An ML-DSA-65 signature is 3,309 bytes, compared with only 64 bytes for a typical Ed25519 signature. Its public key is 1,952 bytes. The selected SLH-DSA-SHA2-128s configuration is larger still, producing a 7,856-byte signature.
That is considerably smaller than the 16-30 KB figures sometimes associated with SLH-DSA. Those larger figures apply to stronger SLH-DSA parameter sets, not the 128s configuration selected by Sui.
Larger signatures mean bigger transactions and more data moving across the network. Sui says ML-DSA verification performance is close enough to Ed25519 that the per-signature network cost does not need to increase, although transaction size still does. Further optimization is underway.
Users Do Not Need to Migrate Today
Quantum-safe vaults are targeted for Mainnet before the end of 2026. Native ML-DSA-65 accounts are expected on Testnet by year-end, followed by native Mainnet account authentication in the first quarter of 2027. Wallet, SDK and command-line support are planned alongside the rollout.
Independent audits and Testnet feedback are still underway, so those timelines could change before the features reach production.
Existing accounts therefore do not need to take any action now. The new authentication methods will be additive and opt-in rather than a forced network-wide migration.
The migration design also creates a simple warning sign for potential scams. Sui’s stated migration path does not require holders to send all their assets to a newly supplied wallet address. Any unsolicited message claiming funds must urgently be transferred elsewhere to become “quantum safe” would be inconsistent with the mechanism Sui has described.
No publicly known quantum computer can currently break the signatures protecting Sui accounts. The relevant question is whether the network can migrate its cryptography before that capability becomes practical.
Sui’s answer is to make the key replaceable without making the account disposable.
- Methodology: This article uses Sui Foundation’s August 6 announcement, official Sui Address Alias documentation and NIST FIPS 204 and FIPS 205 specifications. Signature sizes and security categories were checked against the relevant NIST standards. Features already supported through Address Aliases are distinguished from post-quantum functionality that remains on Sui’s development roadmap.
- Disclaimer: This article is provided for informational and educational purposes only and does not constitute financial, investment or security advice. Sui’s post-quantum features remain under development, independent review and testing, and implementation details or timelines may change before Mainnet release.
Alexander Zdravkov is a market analyst and crypto journalist with interests in economics, broader financial markets and digital assets. His journey into crypto began more than four years ago, driven by a fascination with the rapid evolution of blockchain technology and the transformative potential of decentralized finance. He began analyzing market cycles and identifying emerging trends before they reach the mainstream. He holds a degree in International Relations - a background that helped shape his broader perspective on global economics, geopolitics, and the interconnected nature of modern financial markets. Whether covering the latest developments in the crypto sector or exploring broader macroeconomic themes, Alexander focuses on giving readers context rather than simply repeating headlines. During his career, he has authored more than 5,000 articles covering cryptocurrencies, traditional finance, and global market developments. His work spans everything from Bitcoin and altcoins to macroeconomic trends influencing risk assets worldwide.
