Deian Stefan

Cubist is live on @tempo. Institutions building on Tempo can now use Cubist's high-performance infrastructure to safely and privately automate digital asset operations: 🔐 wallets 🪙 tokenization ⚡️ payments 🤐 private smart contracts

Cross-chain without smart contracts. Excited to see this off-chain approach from @squidrouter. Using Cubist tech, their new settlement protocol can extend to any chain and any token—including chains that don’t have smart contracts—without services like Axelar or LayerZero.

Skate 1-Click is a good example of the seamless UX that becomes possible when Cubist Confidential Cloud Functions (C2F) are used as cross-chain smart contracts. @skate_chain is using C2F to allow users to deposit from Solana, Sui, and other altVMs into top EVM yield protocols.

Squid Intents is the ideal cross-chain protocol. Non-custodial, extremely high success rates, open market pricing, near instant swaps, all chain types Really excited to start rolling it out properly now. Limits are still low ($10k), but will be ramping up

Traditional smart contract wallets have public signing logic. Sometimes you don’t want that. This tutorial shows how to use Cubist C2F to build private smart accounts that can: -use sensitive data privately -call APIs for market and risk data -reuse the same logic across chains

2025 was the year onchain solutions went from experimental to mission-critical. We are proud to power some of the largest infrastructure and asset movements in crypto. Here's how Cubist powered 2025: 🏦 Drove capital efficiency for regulated finance 🔹 Expanded Cubist’s Japanese footprint by supporting a $2T payment provider as they evolve Japan’s legacy financial rails into programmable infrastructure 🔹 Released on-premise and multi-region deployment models to serve institutions who have strict regulatory and performance requirements 🔹 Optimized signing latency that allowed our HFT/market making customers to eliminate hot wallets and safely deploy more capital into their strategies 🔐 Enabled secure and seamless user experiences 🔹 Powered sub-second cross-chain swaps for a major liquidity provider and a popular consumer wallet with tens of millions of monthly active users 🔹 Served as a whitelabeled solution powering a major L1’s new UX-focused Wallet-as-a Service 🔹 Locked down high-value treasury, validator, and smart contract keys holding over $10B for institutional and protocol teams using policy-protected access control 🔹 Voted “Best Hardware Wallet” at The Digital Banker’s Digital Assets Awards 2025 🧩 Developed novel DeFi capabilities 🔹 Launched Cubist Confidential Cloud Functions (C2F) as the industry’s first chain-agnostic solution for private or cross-chain smart contracts 🔹 Extended Bitcoin into programmable DeFi by operating bridge infrastructure that enforces 1:1 BTC backing for wrapped Bitcoin assets totaling over $2B in circulation 🔹 Teamed up with investors to incubate new (soon-to-be announced) companies made possible by Cubist tech We are grateful to our investors and partners who have trusted us on this journey. We aren't just protecting today’s assets; we are building the tools that make entirely new financial models possible. Cubist is proud to power the infrastructure of 2025, and we’re already hard at work building the breakthroughs of 2026.

We are using Cubist's C2F in Coral V2. They've built incredible tech, which we believe is a paradigm shift in how decentralized protocols and apps will be built, especially multichain ones. C2F allows developers to deploy rust code in a tamper-proof, non-custodial way which can read data from any chain, and approve transactions to write data to any chain. We think of this like a multichain rollup, and chose to deploy the Coral there. Coral V2 means: - Chain expansion will be much faster for Squid - Coral is now compatible with all chain types, allowing us to venture further out from the EVM than before - Theoretically optimal pricing and gas efficiency for cross-chain orders - No RFQ expiry times, for lower refund rates and tighter spreads - Approvals not needed - Real-time solver competition - Remaining non-custodial and decentralized - Squid world domination We're fairly sure it can't get much more optimal than this now. Excited for the roll out!

If you peek behind the MetaMask, you'll find yours truly 🫶

And we're LIVE! 🚀 We're thrilled to announce the general availability of Cubist Confidential Cloud Functions (C2F), the first Web3 confidential compute platform that brings smart contract guarantees to private off-chain code. Not only is C2F GA. It’s already being leveraged by leading Web3 teams, including by @squidrouter in the latest version of their Cross-Chain Order Routing and Auction Layer (CORAL). With Cubist C2F, you can: ✅ run compute-heavy logic ✅ execute sensitive logic privately ✅ scale across chains without rewriting everything ✅ apply strong governance and safe upgrade paths to critical code ✅ produce evidence that security and compliance controls are real Run your sensitive, compute-heavy, and cross-chain logic verifiably with Cubist C2F.

At last month's @summit_defi, Cubist Chief Scientist @deiandelmars showed how to use policies-as-code to ensure that the smart contract code you deploy is the code approved by your auditors and built in your CI pipeline. This 🛑stops 🐞buggy and 👿malicious deployments/upgrades👊

We’re thrilled to share that Cubist has been named the winner in the “Best Hardware Wallet” category at the The Digital Banker Digital Assets Awards 2025. This honor reflects our tireless dedication to helping teams deliver the safe, performant experiences that are required to bring digital assets to institutional scale. At Cubist, we started with a simple conviction: If digital assets are to power the future of finance, they need high security and high performance. We built CubeSigner to make this real: it’s the only cloud-based wallet infrastructure offering HSM-enforced self custody combined with the industry’s fastest signing speeds. CubeSigner secures billions in protocol TVL, powers high-frequency trading and stablecoin issuance, funds swaps for popular consumer wallets, and helped bring to market the fastest-growing yield-bearing token in history. Companies are building in entirely new ways using our programmable policy engine and private smart contract functionality, which allows security and compliance rules to remain fully confidential and follow assets cross-chain. Thank you to The Digital Banker and the panel of judges for this recognition.

It’s special when great partners come together. Cubist has long been part of the @avax ecosystem, and now we’re working with @Lombard_Finance to provide the security backbone for the next phase of the BTC.b bridge—deepening Bitcoin’s role in DeFi with permissionless guarantees.

As @avax’s Bitcoin bridge moves to @Lombard_Finance, BTC.b expands its reach. Cubist’s CubeSigner and Bascule Drawbridge will play key roles in the bridge’s trust-minimized, multi-layered security model—powering key management, minting, and withdrawal operations.

Congrats to TIS and @AvaLabs/@AvaCloud on the launch of the Multi-Token Platform, a Japan-based initiative enabling banks and enterprises to issue compliant stablecoins and tokenized assets. We’re honored to work closely with them on their secure key management layer.

Last week my student Ally Nisenoff published "Exploiting the Shared Storage API" at @acm_ccs: andrew.cmu.edu/user/nicolasc/… 3 days later, Google announced they're abandoning Shared Storage: privacysandbox.com/news/update-on… (Correlation doesn't imply causation. Interesting, though.)

@AaronBuchwald @dominic_w Yep, and SRI exists.

@dominic_w What does ICP asset certification actually do? All you should need is a hash to verify the asset against. The relevant code / bytecode can be completely separate.

Solution: serve Safe{Wallet}'s web interface from ICP with asset certification on to make it cryptographically verifiable. Configure so multi-party agreement needed to update assets (e.g via an "SNS" DAO). Safety achieved! DFINITY might do this to kickstart the industry fix.

See how practical security could have saved $1.5B. If you're in Denver, @cubistdev is the team to talk to about practical security measures (whether they are the right fit for you or not).

@AaronBuchwald @hosseeb @cubistdev @turnkeyhq Yeah having policy enforcement in place could really minimize the damage due to malicious/compromised UI. There is definitely a lot we can do on locking down the supply chain, but single dev machine here had way too many privileges.

Agree. But improving frontend security is defense in depth, not fully trusting non air gapped devices. You should have machine enforced policy checks in the loop with @cubistdev or @turnkeyhq like solutions, but if a human is in the loop they still have to verify via some UI. You should not give up on improving frontend security, we can do a lot better. Some ideas: - ask users to opt in to the update - drastically limit what an application can do within the browser or other frontend

Damn. Bybit just released their audit report—the compromise was not Bybit, but SAFE's servers. They hot swapped the Gnosis SAFE UI with JS code that ONLY targeted Bybit's cold wallet. Independently confirmed by WaybackMachine snapshots. Lazarus Group is on another level.

How Tomo Connect Secures Users' Keys: Enterprise-Grade Security with Cubist In the Web3 space, security and user experience often seem at odds. Users have been forced to choose between the security of self-custody or the convenience of centralized solutions (sacrificing control of their assets). At Tomo Connect, we've found a better way with our security partner @cubistdev. Let's explore how we keep your keys safe while making Web3 accessible. How Does Tomo Handle Private Keys? Tomo Wallet prioritizes user security by leveraging CubeSigner, a non-custodial signing service that ensures private keys are never exposed outside secure hardware. We use CubeSigner to securely store and manage private keys within Cubist's virtual Hardware Security Module (vHSM), which is built on top of Nitro Enclaves and FIPS 140-certified HSMs. Private keys are never stored on user devices, and all key-related operations, including signing transactions, occur within secure hardware. Tomo cannot access your keys, and neither can Cubist. Your explicit authentication to the vHSM is required to sign a transaction or export your keys. Users' keys never leave secure hardware without their permission. That's our promise. How Does CubeSigner Work? CubeSigner stores private keys within secure hardware and exposes an API for using these keys, again, without ever leaving the secure hardware. When a transaction request is sent to the CubeSigner API, the transaction is signed within the secure Nitro Enclave using your signing key. The signing key is encrypted at rest and decrypted inside the enclave using a key-wrapping key that is stored within the HSM. This ensures that the signing process is entirely contained within a secure environment, with no raw keys ever exposed. Moreover, this ensures that nobody–not even Cubist–can ever see your keys: they are strictly bound to the secure enclave. Finally, CubeSigner is built in Rust and techniques from language-based security, which together eliminate whole classes of vulnerabilities, and its security is strengthened further through regular audits. Where Do Transactions Get Signed? Transactions are signed inside CubeSigner's virtual HSM, specifically in the secure enclave. Your signing keys are stored as ciphertexts encrypted (using an HSM) with an authenticated encryption scheme (**ChaCha20-Poly1305**) and are only accessible to the enclave. Decryption and signing occur only in the enclave when an authenticated user requests a signature, ensuring raw keys are never exposed in memory, the vulnerable web browser, or any external environment. Keys Recovery Tomo Wallet allows users to recover and export their keys securely. Users can initiate the export process through the wallet interface. Once a request is made, a security measure imposes a 48-hour waiting period to give you time to review and cancel any unauthorized requests. After this period, you are given a short window to complete the export from CubeSigner directly to the endside storage. The keys remain encrypted (from the CubeSigner vHSM to your device) throughout the process, ensuring they are not exposed during export and can be securely transferred to a storage solution. This security architecture is what makes Tomo Connect different from other social login solutions. When users authenticate through Google, Telegram, or any other supported method, they get the seamless experience of Web2 with the security and self-custody of Web3. For developers integrating Tomo Connect, this means you can offer your users the best of both worlds – easy onboarding with social login and enterprise-grade security for their assets.