Anthropic just announced that its Claude Mythos Preview model discovered a new attack that significantly weakens HAWK, a candidate post-quantum signature scheme. HAWK had survived two rounds of expert review over two years. Mythos then spent roughly 60 hours synthesizing known cryptanalytic techniques and found an attack that effectively halved its key strength. To be clear, the attack does not make HAWK practically breakable today, and the scheme has not yet been deployed. But restoring its intended security would require roughly doubling its key sizes, undermining the efficiency that made it attractive in the first place. But there is a much bigger lesson here than an AI model weakening one algorithm. In crypto, the post-quantum transition is often framed as a one-time upgrade: replace ECDSA with a quantum-resistant signature scheme, and the problem is solved. The reality—and what @AnthropicAI’s result reinforces—is that there is no perfect post-quantum signature scheme waiting for us. Every option involves trade-offs, different security assumptions, and the possibility that future cryptanalysis will expose weaknesses we do not yet understand. And this was not a quantum attack. It was AI-assisted cryptanalysis. Just imagine what could happen five, ten, or fifteen years from now, when cryptographically relevant quantum computers are combined with the AI models of the future. We do not intend to fear monger, but it’s quickly becoming super clear that the solution isn’t a one-time upgrade. Instead, as the good folks at @projecteleven point out, the key is crypto agility: the ability to adopt new cryptography, support multiple schemes simultaneously, and migrate away from weakened algorithms without redesigning the entire network. So far, CKB is the only blockchain that can do that. On CKB, signature schemes are implemented in programmable Lock Scripts rather than hardcoded as consensus-level primitives. New schemes can be deployed as code, multiple schemes can coexist, and users can migrate at their own pace without waiting for a network-wide fork. CKB already supports SPHINCS+ on mainnet, but if Anthropic—or anyone else—finds a serious weakness in it tomorrow, CKB is ready to replace it with something better like 🫰that.

This is where architecture matters. If cryptography is baked into the protocol, upgrading it becomes a network-wide coordination event. If cryptographic verification can be deployed at the application layer, the system can adapt much faster. That is why crypto agility matters. In a post-quantum world, the chains that survive will not just be the ones that pick the “right” PQ scheme once, but instead the one’s capable of adapting as cryptography changes.

Quantum resistance is often framed as a signature scheme problem, but that framing is incomplete. A genuine quantum resistant wallet has to address key generation, key rotation, address hygiene, and how the wallet interacts with the underlying blockchain over time. Signature choice is one piece of a broader architectural question. Wallets like Quantum Purse can utilize new cryptographic primitives on CKB because those primitives are not baked into the consensus layer. Instead, transaction verification lives in Lock Scripts, allowing wallets to adopt new signature schemes without requiring core protocol changes. The article walks through how and why. Read the piece: nervos.org/knowledge-base/wh…

How CKB lets developers add new cryptography without protocol changes The typical approach Most blockchains hardcode cryptographic primitives at the protocol layer, often as opcodes, precompiles, or fixed transaction-validation rules. This means that swapping an old one or adding a new one requires a soft fork or hard fork. The whole network has to agree, vote, and coordinate on the upgrade, before users even get to migrate. Start to finish this process can take years every time a new primitive needs to be introduced.

What is crypto agility? The ability of a system to swap its cryptographic algorithms without disrupting how it runs. Past cryptographic transitions have taken decades. DES took 23 years to give way to AES, and SHA-1 retirement still isn't complete. Crypto agility is what makes the next transition faster, and CKB is the only blockchain built this way.

Straight from @Coinbase’s April paper on quantum computing and blockchains. 👇 “Crypto-agility is a highly recommended practice in general [...] even more so in the context of PQC.” Now guess which chains were designed to switch cryptographic algorithms without disrupting operations🧠 Hint: there’s only one.

CKB Has No Plan — But We Do. Our previous posts about roadmaps generated some controversy. We’re grateful to have your attention. Because this distinction matters. CKB doesn’t have a roadmap because it is public infrastructure, not a product operated by a company. The goal of any serious blockchain is not endless reinvention. It is to become a stable, secure, and predictable infrastructure that others can build on for decades. That said, CKBA absolutely has plans. CKBA exists to coordinate stakeholders and grow the CKB ecosystem across the areas that matter most. That means organized work to attract builders, identify use cases, improve developer onboarding, fund ecosystem initiatives, pursue partnerships, clearly communicate CKB’s value, and actively engage the teams, companies, and communities that can drive real usage on the network. Having reorganized and unified several teams under a single structure puts us in a stronger position than ever to execute on these goals. A ton of work is already underway, especially on the Fiber front: improving the stack and documentation, advancing Lightning interoperability and liquidity management, and identifying and removing blockers for adoption. Work is also ongoing on the design and implementation of the DAO's on-chain treasury and voting mechanisms. And while there are many other initiatives in the pipeline that we’ll share when the time is right, there’s one that demands immediate attention 👇 Three months ago, Google Quantum AI published a bombshell paper showing that quantum attacks against secp256k1—the elliptic curve behind the signatures used by most blockchains—may require far fewer resources than previously estimated. In simple terms, the paper made the quantum threat to cryptocurrencies harder to ignore. The industry conversation that followed was, as expected, hard to miss — and yet it missed CKB. No mention in the paper, no mention in the con im versations on X and various forums, no mention anywhere. To put it bluntly, this is a huge communication failure on our part. CKB is the only cryptographically agile blockchain in existence, and therefore one of the few that’s already quantum ready. It’s the only chain where devs can bring new post-quantum signature schemes permissionlessly. No need for soft or hard forks. No need to pick a single PQ scheme and bake it in as a precompile. CKB is the only chain that can switch between different crypto primitives without disrupting operations or requiring significant infrastructure redesign. It’s the true embodiment of crypto-agility — yet barely anyone was aware of it. So, our first course of action on the communication front is to remedy that. We’ll run a comprehensive marketing campaign that’ll put CKB at the forefront of the Quantum x Blockchain discussion and position it as one of the few projects with a future-proof solution. And we want all of you involved. If you care about CKB and want to help push this forward, reach out. If you’re a developer, researcher, writer, designer, translator, community organizer, content creator, or just someone willing to help amplify the message, we want to hear from you. This campaign should not be about what CKBA has to say. It should be about making CKB impossible to ignore. We’ll be opening channels for community participation soon. In the meantime, reply here, DM us, or join the discussion on Nervos Talk.

Last year was a big one for CKB!🎊 From the smooth activation of the Meepo hard fork to the launch of the first quantum-resistant wallet, we saw major technical milestones crossed while projects across the ecosystem continued to grow and ship📈 Dive into the full 2025 Annual Report to see everything that happened ↓ nervos.org/assets/pdfs/Nervo…

We are happy to share that Nervos CKB is quantum-adaptive! Post-quantum cryptography is now available to any user of CKB. SPHINCS+, a NIST-standardized hash-based cryptography algorithm, was deployed as an on-chain script without requiring consensus changes or soft/hard forks. (github.com/cryptape/quantum-…) @quantumpurse, a self-custodial CKB wallet for Linux/Mac/Windows, is the first cryptocurrency wallet to support SPHINCS+. It offers the highest level of post-quantum security available today, with compatibility for the decades to come. While conversation and coordination around the potential quantum threat will continue to grow, CKB’s flexibility has allowed for seamless adaptation to these new demands. CKB has been prepared to face the potential threat posed by quantum computers since launch. This implementation demonstrates the quiet strength of the Nervos project: headline-worthy functionality with no high-stakes discussions or coordinated upgrades, using well-vetted standard libraries and tools, done through an open source community of developers. We look forward to sharing more about its unique design and the RISC-V virtual machine, CKB VM, in the coming weeks. Please join us in extending our warmest congratulations to the @Cryptape and @quantumpurse developers on this historic achievement.