A comparison of ARMchain and Nervos CKB in the context of post-quantum blockchain design, examining two distinct approaches to quantum resistance, cryptographic architecture, consensus, and scalability as the industry prepares for the impact of quantum computing on modern cryptographic systems.
Google's recent quantum security update is no fun.
Think about it: accelerating timelines means quantum computing breakthroughs is right upon us. With Google effectively signaling at the arrival of "Q-day" to be within THIS decade, not the next one, this clearly means transition to post-quantum cryptography is no longer optional!
This rapid shift holds immediate consequences for systems operating in the blockchain space because quantum computing directly undermines the foundational security of blockchain networks. What was once considered a sci-fi concept or a distant cryptographic risk is now becoming a very real systemic architectural problem.
Against this backdrop, multiple innovative companies are working to build blockchains on the principles of post-quantum cryptography. Two of these quantum-resistant blockchains are ARMchain and Nervos CKB. While one is natively built for the quantum era, and has MLDSA integrated right into its foundational architecture, the other takes a modular approach. Today, let's debate this contrast and how they can help the users.
The urgency behind shifting to post-quantum blockchain design comes from the simple but critical reality that today's blockchains were never built to withstand the cryptographic foundations of quantum attacks. Majority of blockchains rely on traditional cryptography to secure the network. This cryptography uses elliptic curves to protect the system integrity and are considered secure against classical computing assumptions.
The problem is, ECDSA collapses under the Shor's algorithm which can easily derive private keys from public keys. Due to this vulnerability, practically, any quantum computer with sufficient power will be able to reconstruct the ownership of any blockchain asset as soon as a public key is exposed.
This creates a structural vulnerability, which was severely underestimated up till now:
This is why the shift towards post-quantum cryptography is now more urgent than ever.
Let's start with the design: ARMchain is designed quantum-ready by default whilst Nervos CKB treats cryptography as an interchangeable component within the computation framework of its architecture.
With ARMchain, traditional elliptic-curve signatures are replaced with MLDSA - a lattice-based signature scheme that's standardized by NIST. This means ARMchain's system is fully decoupled from ECDSA dependency and has native PQC integration at protocol level.
What's more interesting is that this layer 1 quantum resistant blockchain offers EVM compatibility for the developer's experience. This allows for seamless migration without requiring developers to rewrite contracts or change tooling.
Nervos CKB is built on a cell model and is powered by RISC-V. What it does is allow developers to define custom validation logic and cryptographic primitives including PQC signature schemes.
So, by default the reliance is on ECDSA, but users can opt for PQC-based signatures incrementally via scripts. This blockchain also offers EVM compatibility, but the execution environment is designed for flexibility via Godwoken Layer 2.
The thing is, at the heart of ARMchain vs. Nervos CKB comparison, a fundamental question stands: should quantum resistance be enforced at protocol level, or be left out as an optional upgrade option? See, both approaches aim to solve the same threat, but they diverge sharply on aspects like how security is applied and maintained.
With ARMchain, the approach is quite clear: a strict, enforced, protocol-level security model for all users where post-quantum cryptography is not optional. We have integrated MLDSA directly into the core transaction and validation logic and replaced traditional signature schemes entirely.
What this means: Every account signature is lattice-based on genesis, and validators participate under the same PQC standard. The key advantage of this approach is that there is no fragmentation of risk remains. Moreover, the risk of exposure to "harvest-now-decrypt-later" attacks is significantly reduced.
On top of this foundation, ARMchain has introduced crypto-agility at the account layer which means that any future upgrades to post-quantum standards can easily be adopted onto the network through soft protocol evolution without requiring any user-side migration.
Nervos CKB adopts a flexible approach towards PQC adoption and migration. So, basically, the default scheme is traditional ECDSA cryptography, but PQC mechanisms can be enabled through optional scripts. In this case, quantum resistance is not enforced, so assets do remain vulnerable unless they are explicitly migrated towards PQC-enabled scripts.
The benefit of this model is maximum flexibility as developers can add new cryptographic schemes as per requirements via scripts. However, due to this design choice full network security is not immediate, and legacy ECDSA-based assets do remain exposed to quantum attacks for a transition period.
Beyond design and security, the real-world viability of any blockchain system also depends on how efficiently it operates under load. PQC-based signatures inevitably introduce unavoidable computational and storage overheads. As a result, both Nervos CKB and ARMchain make distinct architectural choices to balance the trade-offs with performance and scalability.
ARMchain's architecture is engineered for deterministic performance. The interesting thing about ARMchain is that ARMchain's transaction inclusion speed can vary depending on network conditions, while finality of the transaction remains instant once inclusion occurs.
The core mechanism of finality guarantees in ARMchain is aBFT consensus (Lachesis-style architecture) which ensures that once a transaction is included in a block and confirmed by the network, it cannot be reversed via forks or reorganizations. This removes uncertainty of settlement risk from settlement even if block production timing fluctuates.
Because finality is immediate upon inclusion, ARMchain significantly reduces the time window of exposure in which state transitions can be exploited in a post-quantum environment where minimizing exposure time is part of the security model itself. This makes it well-suited for DeFi, real-time payments, and execution layers of institutional systems where certainty of finality matters more than rigid block production timing.
Nervos CKB's entire focus is long-term state efficiency and decentralization-first architecture for stability. For this purpose, the network uses a cell model which avoids global state bloats by treating each transaction output as an independent state container. By doing so, Nervos CKB improves long-term sustainability.
One interesting thing about Nervos is that their Proof-of-Work consensus is optimized via NC-Max. What this does is optimizing block propagation for the reduction of forks which results in reduced orphan rates. This is especially useful for enterprise-grade organizations that require high levels of security for the integrity of transactions.
So, while using SPHINCS+ as their hash-based signature does introduce heavier computational and storage costs, the architecture of Nervos mitigates this overhead through its layered architecture. The heaviest computation of execution workloads is pushed to Layer 2, while the base layer of Nervos CKB remains focused on settlement, data integrity, and security.
As the Q-day is approaching us in the coming years, the shift towards PQC-based systems is inevitable. Today, we spoke about two strong Layer 1 blockchains that have set up two different approaches to quantum resistance and help build with a post-quantum blockchain infrastructure.
ARMchain, on one hand, is built with native quantum resistance and protocol-level ML-DSA integration. While Nervos CKB, on the other hand, focuses on crypto-agnostic modularity and long-term adaptability via cell model approach. Both these systems are designed to address the same underlying quantum threat but with different strategies for security, which differs in execution philosophy.
As quantum computing continues to advance, the real-world effectiveness of each of these approaches will also continue to show how security, performance, scalability, and broader ecosystem adoption evolves in practice.