Sonic Unveils Post-Quantum Upgrade Plan for Its Blockchain

Highlights:

• Sonic says its blockchain can adopt post-quantum signatures without changing its core consensus design.
• The team warns many proof-of-stake networks may face harder and more costly upgrades.
• Sonic believes its simpler DAG-based structure could make future quantum transition more manageable.

Sonic is preparing its proof-of-stake (PoS) blockchain for a future where quantum computers may weaken the digital signatures used across crypto networks. In a research post published on Monday, the team said its DAG-based SonicCS consensus protocol can support post-quantum signatures without changing the core design. 

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Sonic Says Its Design Could Ease the Quantum Transition

Sonic added that this could make the transition easier than on many other proof-of-stake networks, especially those that rely on signature aggregation and threshold cryptography.

The main risk lies in the cryptography most blockchains still use today. Many networks depend on elliptic-curve systems such as ECDSA and Ed25519 to secure wallets, validator identities, and transactions.

Sonic said a powerful enough quantum computer running Shor’s algorithm could break that math. As a result, an attacker could recover private keys from public keys and forge signatures. The company added that hash functions are still seen as usable in a post-quantum setting, but elliptic-curve signatures would need to be replaced.

Quantum computers will eventually break the elliptic-curve cryptography most blockchains rely on.

SonicCS avoids all of that: its minimal cryptographic design means going post-quantum is just a single signature swap. pic.twitter.com/XJpckN5b7g

— Sonic (@SonicLabs) April 20, 2026

Quantum Threat to Blockchain Signatures

Blockchain security mainly relies on two cryptographic tools: digital signatures and hash functions. Digital signatures confirm ownership and verify validators. Hash functions connect blocks and help make the chain hard to change.

Sonic said quantum computers are a major threat to signature systems based on elliptic curves. In contrast, hash functions are still considered more secure under post-quantum assumptions and may require only minor changes, such as larger output sizes.

He said the industry still needs to prepare early. Post-quantum signature systems such as Dilithium, Falcon, and SPHINCS+ are based on mathematical problems believed to withstand both classical and quantum attacks. He added that moving to these standards is important for long-term blockchain security.

Aggregation Limits Quantum Upgrade Path

Many proof-of-stake networks use signature aggregation to work more efficiently. Systems like HotStuff and Tendermint combine many validator signatures into one small certificate through BLS aggregation. This helps reduce bandwidth usage and speeds up verification.

However, post-quantum options do not support this process as easily. Sonic said lattice-based signatures are larger, while hash-based signatures can become much bigger. The company also noted that there is still no NIST-standardized post-quantum alternative to BLS aggregation.

Because of this, blockchains that rely on aggregated certificates may face a more difficult upgrade path. A move to quantum-safe signatures could increase message sizes, slow verification, and put more pressure on network bandwidth. In some cases, projects may need to redesign key parts of their consensus system. Sonic called this problem the “aggregation trap,” and said it could make quantum readiness more difficult for many established chains.

How SonicCS Simplifies the Upgrade Path

SonicCS uses a different design. It runs on a directed acyclic graph, or DAG, where validators share signed events with each other. Each event only needs a normal digital signature from its creator and a hash link to earlier events.

Sonic said this design avoids tools like BLS aggregation, threshold signatures, and a global randomness beacon. Instead, the protocol relies on a simpler setup to keep the network running.

Because of this, Sonic believes the move to post-quantum security could be easier. When stronger standards are ready, the team can replace its current signature system with a NIST-approved option such as Dilithium or Falcon. It can also increase hash sizes for extra protection. Sonic said the core consensus logic, DAG structure, and network communication would stay the same, so a full protocol redesign would not be needed.

The company added that this flexibility stems from closely controlling its consensus system. It also plans to follow Ethereum Foundation research on post-quantum upgrades to keep its roadmap aligned with wider industry efforts.

As concerns over quantum threats grow following Google’s warning, more blockchain projects are considering upgrades. Recently, Ripple outlined a plan to prepare the XRP Ledger for potential quantum risks. Moreover, Tron is also taking early steps to address future threats.

RIPPLE: $XRP LEDGER WILL BE QUANTUM RESISTANT BY 2028@Ripple is making its $XRP Ledger quantum-ready. These super-fast machines could one day break the codes that protect digital money today.

The company has a clear plan to complete the upgrades by 2028 across four phases in… pic.twitter.com/RsA5jY2uqb

— BSCN (@BSCNews) April 20, 2026

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