Squads Tests Falcon-512 Post-Quantum Signing on Solana Mainnet

How Falcon-512 Signing Works

Falcon is a digital signature scheme based on lattice cryptography. Its name stands for Fast-Fourier Lattice-based Compact Signatures over NTRU. It was developed as a signature method intended to resist attacks from quantum computers that could eventually undermine some cryptographic systems used today.

The National Institute of Standards and Technology’s post-quantum cryptography programme selected Falcon for standardisation, with the corresponding FIPS 206 standard still under development as of the information published by NIST. Post-quantum cryptography aims to prepare digital systems for the possibility that future quantum computers could break widely used public-key cryptographic techniques.

Squads’ implementation uses Vector, an offchain verification programme developed by Blueshift. A voting member signs a transaction instruction using Falcon-512, after which Vector checks the signature against the expected digest. If verification succeeds, the system authorises a Program Derived Address (PDA) to take part in the multisig approval process.

Adding Post-Quantum Authentication Without Rebuilding Multisig

The approach allows Squads to introduce an alternative signature scheme while retaining its existing onchain multisig programme. That programme continues to handle permissions, proposals, approvals and transaction execution.

Squads’ account abstraction model can accommodate different types of participants, including traditional wallets, PDAs controlled by other programmes and nested multisig accounts. By adding Falcon-512 to its key-management interface, the team is exploring how alternative cryptographic methods can fit into existing transaction-approval workflows.

Other post-quantum options, including ML-DSA-44, Winternitz and XMSS, are marked as coming soon in the supplied product information. Their inclusion does not mean they are already available for general use through Squads.

Mixed Signature Schemes Could Add Security Diversity

One potential advantage of the design is that multisig participants can use different signature schemes within the same approval structure. This could allow teams to adopt post-quantum signing gradually rather than requiring every participant to migrate at once.

Consider a 2-of-3 multisig configuration with two Falcon-512 signers and one traditional Ed25519 signer. Two approvals are needed to meet the threshold. If the Ed25519 signer’s key were compromised, an attacker would still need access to at least one Falcon-512 signer to obtain the required approvals, assuming the other security controls remained intact.

This example illustrates the value of cryptographic diversity, but it is not a guarantee against every attack. Security depends on implementation quality, key management, the integrity of the verification process and the specific transaction configuration.

Solana’s Fee-Payer Requirement Remains a Limitation

The Falcon-512 test does not make every part of a Solana transaction post-quantum resistant. Solana transactions still require a native Ed25519 signature from the fee payer, which covers the transaction fee in SOL, even when Falcon-512 is used for multisig authorisation.

Squads has proposed separating the fee payer from the account controlling the treasury. Under this approach, a rotating fee payer could hold only the SOL needed to cover transaction costs. Limiting the balance held by that account could reduce the amount directly exposed if its signing key were compromised.

However, separating fee payment from treasury control does not remove the native signature requirement or make the entire transaction quantum-resistant. It is a risk-management approach aimed at limiting exposure rather than a complete solution to the broader cryptographic challenge.

Solana Developers Consider Future Quantum Risks

The test comes amid wider discussion about how blockchain networks should prepare for potential advances in quantum computing and AI-assisted mathematical research.

Solana co-founder Anatoly Yakovenko called on wallet developers on October 8 to begin implementing post-quantum cryptography and establish reliable processes for managing and rotating cryptographic secrets. Ethereum Foundation researcher Justin Drake has also urged the crypto industry to consider defensive measures against possible breakthroughs in AI-driven mathematics.

The risk remains prospective. There is no public evidence in the supplied material that AI has broken the major cryptographic assumptions underpinning widely used digital signatures. Progress in AI research does not, by itself, demonstrate that attackers can defeat established signature schemes.

What the Mainnet Test Means

Squads’ Falcon-512 test demonstrates one way to add an alternative signing method to an existing Solana multisig workflow. The planned SquadsX integration could make the option more accessible to users once it is released, although the supplied announcement does not specify a release date.

The wider challenge involves more than selecting a quantum-resistant algorithm. Blockchain developers must also address secure key generation and storage, signature verification, migration procedures and the dependencies that remain tied to existing cryptographic systems.

For now, the milestone represents an early step toward post-quantum multisig authorisation—not a claim that Solana or all assets managed through Squads are already protected against quantum attacks.