Cryspen

Alex will be speaking at Leaning In! 2026 in Berlin this Thursday, March 12. In his presentation, "Verifying security-critical Rust code with Lean," he will introduce Hax, Cryspen's toolchain for transpiling annotated Rust into monadic Lean code. Event details: buff.ly/YcuZTVB

🚀 Protect your data against harvest-now-decrypt-later attacks with PSQ! We’ve built a lightweight, hybrid post-quantum protocol that injects HNDL security into your existing protocols. The easiest way to start your post-quantum transition today without rewriting your entire stack. buff.ly/irOf0lH

🚀 We’re growing! Cryspen is hiring. Are you passionate about high-assurance software or cutting-edge cryptography? We are looking for talented individuals to join our team. 🔹 Compiler and Verification Tools Engineer 🔹 Cryptography Engineer 👉 Apply here: buff.ly/J9TF6NB #Hiring #TechJobs

New blog post is live! 🦀 We used hax and F* to formally verify termination and panic freedom for a small real-world Rust crate. We also put Kani, Verus, and Aeneas to the test on the same code, exploring the different approaches, challenges, and proof efforts required by each tool. buff.ly/h5bG37W

Catch Karthik, our Chief Researcher, at the European Conference on PQC Migration next week, where he will be championing the need for the EU to implement provably secure protocols and high-assurance software. See you there? 👋 📅 Dec 2-3, 2025 🔗 buff.ly/w3XMpJQ #PQC #EU

We're thrilled to welcome Alexander Bentkamp to the Cryspen family! Alex joins our Tools and Proofs team with a deep background in automated and interactive theorem proving. Welcome aboard, Alex! buff.ly/jsJHshv

Headed to #escar this week? ​Catch Franziskus talking high assurance crypto. And don't miss Karthik's keynote at the "PQC Migration & Supply Chain Readiness" workshop. Lets connect and talk #verification and #cryptography. buff.ly/UPf2MiN ​#AutomotiveSecurity #PQC #Crypto #SupplyChain

We are excited to share that Karthikeyan Bhargavan, co-founder and chief research scientist at Cryspen, will give a keynote talk at the PQCSA "PQC Migration & Supply Chain Readiness for the Automotive Industry" workshop (co-located with ESCAR in Frankfurt).

Excited to share our latest work on formally verifying the Rust standard library! We developed a new methodology to specify and test the Rust core library, helping to find and fix a bug in Rust's platform-specific SIMD functions. Learn more about our approach: buff.ly/IwMkWVm

In Taipei for CCS 2025? 🇹🇼 Our CEO, Franziskus Kiefer, is giving a talk on Formal Security & Functional Verification of Crypto Protocols in Rust. Don't miss the chance to connect. Franziskus is keen to discuss the future of secure software development and cryptography.

Attending the OpenSSL conference? 🗣️ Our Chief Researcher, Karthikeyan Bhargavan, is giving a talk on high assurance post-quantum cryptography. He'd love to connect, so come find him for a chat about the future of crypto! buff.ly/JIGSr0L #OpenSSL #PQC #PostQuantum #Cryptography #Cybersecurity

We're excited to see the release of Signal's new post-quantum ratcheting protocol, SPQR! We are proud to have collaborated with the Signal team on the formal analysis of the design and implementation of this. Learn more on our blog buff.ly/Zi3rCBs and in Signal's announcement buff.ly/Srroli9

How do we prove our cryptography is secure? 🧐 Join a talk by our Chief Researcher, Karthikeyan Bhargavan, on the rise of formally verified crypto! #cryptography #formalverification #cybersecurity #PQC #infosec

JZLint 2.0 is here from MTG & Cryspen to lint post-quantum certificates! Now supporting ML-KEM & ML-DSA via libcrux. Read more detail on the blog: buff.ly/EviQFar #PQC #cryptography

Safer web browsing now possible thanks to spinout tech rooted in academic research. 🔐 On #WorldWideWebDay note Karthikeyan Bhargavan & team at Inria who developed tools to improve cryptographic security online. 👉 europa.eu/!hP6t8w #ERCPoC #AI #Cryptography #Encryption #WebSecurity @cryspen.com

We're launching the embedded-cal project: Providing access to hardware accelerated and formally proven cryptographic algorithms on #embedded systems in #RustLang. For this, I'm teaming up with @inria Paris and @cryspen, supported by the #EU funded @NGIZero. Right now we're going through […]

As of today, XMTP is now a fully quantum-resistant decentralized messaging protocol. This means, any developer, anywhere in the world can leverage XMTP to provide their users with private, decentralized, & quantum-resistant messaging.

We're proud to be recognized by Wavestone on their 2025 Radar of French Cybersecurity Startups. A significant milestone that validates our core mission: building the essential developer tools for creating high-assurance software. Making provably secure software accessible to all developers.

Cloudflare has launched Orange Me2eets, an open-source end-to-end encrypted video calling demo! Built on top of our OpenMLS implementation, this project showcases secure, private real-time communication. buff.ly/eEdJdnf #Cloudflare #E2EE #VideoCalling #OpenSource #OpenMLS

At IEEE S&P, Théophile Wallez presented new results on the formal security verification of a bit-precise executable specification of TreeKEM, the core key agreement component of the MLS protocol. This work was done in collaboration with chief research scientist Karthikeyan Bhargavan.

Thrilled to welcome Clément to Cryspen's Tools and Proofs team! 🎉 His expertise in formal methods (PhD from Inria Paris!) will be for conducting rigorous proofs and enhancing our tooling. Welcome, Clément! 🚀 #NewHire #FormalMethods buff.ly/Ab4wuNA

Updates from some of Cryspen's Open Source Projects! Check out our latest updates: - Dive into the latest developments from the past month on 𝐡𝐚𝐱. buff.ly/trIZnTx - And see how the 𝐎𝐩𝐞𝐧𝐌𝐋𝐒 project is progressing and what's on the horizon. buff.ly/LAxrwnH

MLS Group State Forks: What, Why, How Group state forks are faulty states that MLS groups can end up in. We have a new blog post that looks at what they are exactly, how that happens and how to resolve them, and how a a new OpenMLS feature makes fork resolutions a little easier.

Rust identifiers, demystified! We're revealing our analysis toolchain's secrets in our latest blog. Discover how we tackle global vs. local identifiers for better formal verification with hax. Read the full story: buff.ly/fWGDzLY #RustLang #CodeAnalysis #HighAssurance

Updates from some of Cryspen's Open Source Projects! Check out our latest updates: - Dive into the latest developments from the past month on 𝐡𝐚𝐱. buff.ly/TJpxWW1 - And see how the 𝐎𝐩𝐞𝐧𝐌𝐋𝐒 project is progressing and what's on the horizon. buff.ly/VAJxltR

RWC 2025 buzzed with energy as the cutting edge of cryptography was presented to and discussed among an audience. Today, Cryspen teamed up with Google to showcase practical, scalable, verified solutions for high-assurance software and post-quantum cryptography.

New blog post! 📝 Control flow analysis with Hax. In this post we show how to ensure control flow properties such as "function A is always called before function B" in Rust. Super relevant for security! 🔒 buff.ly/ntTW299 #rustlang #formalverification #security

Thank you to new sponsors of Real World Crypto 2025, CASA, Chelpis Quantum, Cryspen, and Interop Labs! Your contributions are essential in making this conference possible and we look forward to seeing you in Sofia!

Cryspen is heading to RWC in Sofia next week! 🚀 We'll be presenting "Using Formally Verified Post-Quantum Algorithms at Scale" and our team will be on hand to discuss all things high assurance software and crypto. Oh, and we're sponsoring too! buff.ly/IC7eg8O #RWC #Cryptography #PostQuantum

Exciting to see MLS gaining traction! 🚀 This increased adoption is a huge win for security and privacy in messaging. #MLS #Security #Privacy #XMTP #OpenMLS

New Blog Post: Making hax More Usable for Everyone! We've just published a new technical blog post detailing our ongoing efforts to improve hax. Learn about the strategies and implementations we're employing to make hax more usable and efficient for all users.

We welcomed Clara to the Cryspen team this month! She's a TU Berlin grad, a Rust enthusiast, and a passionate open-source contributor. Her skills in low-level programming and commitment to secure software make her a perfect fit for our mission.

We are excited to be part of the PROTECT team to develop new approaches to make IT systems more resilient. www.dfki.de/en/web/news/...

Our paper "hax: Verifying Security-Critical Rust Software using Multiple Provers" is now available on eprint and will be published in the VSTTE 2024 proceedings.

🚀 hax is entering a new era! 🚀 We're excited to announce the launch of our new website and our first official release! Check out our latest blog post to learn more about this exciting new chapter 🔗 https://hax.cryspen.com/blog/2025/01/21/a-new-chapter.html #opensource #hax

Cryspen is thrilled to be part of the "Verifiably Secure IT Ecosystem" funded by the Cyberagentur! 🚀

Test your PQC readiness now! Our new website, featuring our formally verified libcrux crypto library, makes it easy to see if your browser is future-proof. Head over to https://buff.ly/4ak1LB6 to test your browser and learn more about post-quantum cryptography. #postquantumcrypto #cryptography

Cryspen is looking for a talented Proof Engineer to join our team in Germany or France! 🇫🇷🇩🇪 Cryspen is on a mission to build high-assurance software and formal verification tools that make the world a safer place. https://buff.ly/4jeEJiN #ProofEngineering #Hiring

Great News! Cryspen's libcrux crypto library was mentioned in a recent article in The Register. If you're interested in learning more about how libcrux can be used to improve the security of your applications, please visit our website or contact us.

bertie.cryspen.com now available with mlkem TLS and Bertie We've launched bertie.cryspen.com with mlkem TLS, powered by our Bertie TLS 1.3 implementation. This provides a secure and efficient endpoint for your applications. Read more here: https://buff.ly/3ZOiJT3 #mlkem #TLS #pqc

Updates from Cryspen's Open Source Projects! Check out our latest updates: - Dive into the latest developments from the past month on 𝐡𝐚𝐱. buff.ly/3VgVccc - And see how the 𝐎𝐩𝐞𝐧𝐌𝐋𝐒 project is progressing and what's on the horizon. buff.ly/4fVzNgX

📣 Upcoming Event! Our next Berlin Crypto Meetup is coming up! We've got two great talks lined up. Be part of the growing Berlin crypto community. 📆 December 4 🕖 From 19:00 to 22:00 📍 Secure Systems Engineering GmbH Hauptstraße 3 10827 Berlin www.eventbrite.de/e/berlin-cry...

Cryspen is looking for a talented Rust Software Engineer to join our team! 🇫🇷🇩🇪 join.com/companies/cr... We encourage applications from all qualified candidates, regardless of their background or identity. #Hiring

At VSTTE 2024 in Prague, Karthik spoke about how formal verification can be used to speed up the development and clarify the security of real-world cryptography from design to implementation. Slides are up! Check them out. cryspen.com/post/vstte20...

Our Chief Researcher, Karthik, is giving an invited talk today at VSTT in Prague! He will delve into the fascinating world of modern cryptography and software verification and discuss how formal verification is being used to improve the security of real-world systems.