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
Leaning In! 2026
A workshop for the Lean community - Thursday, March 12, 2026
leaning.in
🚀 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
PSQ: Post-Quantum Shared Secrets Made Easy
We’re pleased to announce the PSQ protocol for establishing a hybrid post-quantum shared secret between two parties. Cryptographic protocols, which exclusively rely on classical public key…
cryspen.com
🚀 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
Jobs at Cryspen | JOIN
Jobs at Cryspen. Browse all our open positions and become part of our growing team! We are currently looking for additions to our company. Apply today!
join.com
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
Verifying a real world Rust crate - hax
In this post, we are going to use hax and F* to verify a small real world Rust crate. Then, we will try other verification tools (Kani, Verus, Aeneas) to the same thing. The Rust crate gcd by Corey…
hax.cryspen.com
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
Cryspen Welcomes Alex
We welcome Alex to Cryspen
cryspen.com
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
escar Europe - The World's Leading Automotive Cyber Security
22. escar Europe - November 19 to 20, 2024, Dortmund (Germany)
escar.info
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
Formally Specifying and Testing the Rust Standard Library
Cryspen found and fixed bugs in the Rust SIMD libraries using formal specs
cryspen.com
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.
ACM CCS 2025
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buff.ly
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
OpenSSL Conference Prague 2025 | October 7-9, 2025
OpenSSL Conference Prague 2025 | October 7-9, 2025
buff.ly
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
Helping Secure Signal's Post-Quantum Transition
Cryspen worked with Signal to formally analyze their new post-quantum ratchet
buff.ly
Submissions for RWC 2026 are open now! Real World Crypto (RWC) is an annual event where cryptographers and security engineers can exchange ideas and results on the use of cryptography in mainstream applications. buff.ly/0PoLe2D
RWC 2026
Real World Crypto Symposium
rwc.iacr.org
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
High-Assurance Post-Quantum Cryptography OpenSSL Conference
Recent years have seen several landmark results in the formal verification of high-performance cryptographic libraries, leading to verified crypto code being adopted by mainstream projects like…
buff.ly
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
PQC Support for JZLint
MTG and Cryspen release JZLint 2.0: A tool for analyzing post-quantum certificates
buff.ly
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 […]
Original post on chaos.social
chaos.social
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.
Radar des startups cybersécurité françaises 2025
Wavestone, en partenariat avec Bpifrance, a le plaisir de publier son Radar de l’innovation cybersécurité français 2025.
wavestone.com
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
Orange Me2eets: We made an end-to-end encrypted video calling app and it was easy
Orange Meets, our open-source video calling web application, now supports end-to-end encryption using the MLS protocol with continuous group key agreement
blog.cloudflare.com
Cryspen is excited to announce it has been awarded a grant from the Ethereum Foundation to extend our hax verification toolchain with support for the Lean prover. Watch this space for more on this soon! #FormalVerification #Lean #Rust
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.
TreeKEM: A Modular Machine-Checked Symbolic Security Analysis of Group Key Agreement in Messaging Layer Security
The Messaging Layer Security (MLS) protocol standard proposes a novel tree-based protocol that enables efficient end-to-end encrypted messaging over large groups with thousands of members. Its…
buff.ly
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
Cryspen Welcomes Clement
A Warm Welcome to Clement, Our Newest Cryspen Crew Member!
cryspen.com
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
This Month in Hax: April 2025 - hax
In April, we successfully merged 38 pull requests!
hax.cryspen.com
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.
MLS Group State Forks: What, Why, How
What are state forks, why can’t they happen but do anyway and how can they be resolved in OpenMLS?
buff.ly
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
Redesigning Global Identifiers in hax - hax
A careful treatment of identifiers lies at the heart of all code analysis frameworks, and we hope our experience here proves useful to others.
buff.ly
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
This Month in Hax: March 2025 - hax
In March, we successfully merged 32 pull requests!
buff.ly
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.
Cryspen @ RWC 2025
Real World Crypto 2025 buzzed with energy as the cutting edge of cryptography was presented to and discussed among an audience of leading researchers and developers from academia and industry. Today,…
buff.ly
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
Control flow analysis with hax
A difficulty of formal verification is that specifying programs can be hard. Certain kinds of programs can end up having a specification that is as complex as the code itself. In this case it is…
buff.ly
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!