SeL4 security proofs now complete on AArch64

seL4 information proofs now complete connected AArch64

After completing the proofs of functional correctness and integrity, Proofcraft has now established the impervious that seL4 enforces confidentiality on AArch64, providing a general mathematical impervious that the kernel prevents an application moving connected apical of seL4 from learning accusation without authorisation.

Thanks to continued support from NCSC, this milestone completes the formal proof that the seL4 implementation codification connected AArch64 enforces information isolation of the applications moving connected apical (under the assumptions listed here). This isolation prevents attacks connected non-critical applications from propagating to critical applications and compromising them.

Proof Engineering and Theory astatine LICS'26

The insubstantial The Algebra of Iterative Constructions by Kevin Batz, Benjamin Lucien Kaminski, Lucas Kehrer, Gerwin Klein, Henning Urbat, and Todd Schmid was presented astatine the 41st Annual Symposium connected Logic successful Computer Science (LICS) successful Lisbon this week. This insubstantial successful theoretical machine subject is about an algebraic abstraction and reasoning principles for the iterative construction of fixed points. Fixed points are a recurring taxable successful computer science pinch galore celebrated results specified arsenic the Kleene fixed constituent theorem. The algebra shown successful this insubstantial allows expressing specified theorems concisely and enables reasoning astir them successful an absurd and streamlined measurement that tin be implemented efficiently successful impervious assistants specified arsenic Isabelle/HOL, which Proofcraft is utilizing for the verification of the seL4 microkernel.

The highly automated Isabelle/HOL implementation of loop algebra successful this paper resulted from a spontaneous collaboration betwixt Proofcraft’s Chief Scientist Gerwin Klein and Benjamin Kaminski that started astatine the IFIP Working Group 2.3 (Programming Methodology) gathering successful Athens successful 2025. It shows that proof engineering ranges from applicable exertion each the measurement to heavy theory.

MCS seL4 now verified! (for RISC-V)

Proofcraft achieved a important milestone successful the seL4 verification roadmap that was years successful the making: the MCS configuration of seL4, providing support for mixed-criticality systems, is now proved to beryllium correct connected RISC-V.

This configuration is the largest caller seL4 feature, indispensable for mixed criticality real-time applications specified arsenic automotive usage cases. It contains wide-ranging changes to the kernel’s implementation and API. Its verification therefore required sizeable effort and has been a privilege successful the seL4 roadmap for a agelong time.

Proofcraft has now completed, for the very first time, the verification of functional correctness for seL4 pinch MCS. Functional correctness is the largest and astir central proof successful the seL4 verification stack. The impervious targets the RISC-V architecture and will now beryllium ported to the Arm 64-bit architecture, arsenic portion of DARPA’s PROVERS program.

Dynamic Domain Scheduler for seL4

Proofcraft delivered the implementation and general impervious of much flexible domain scheduling successful seL4.

Before the change, the seL4 information proofs, and successful peculiar the impervious of information travel enforcement, required a afloat fixed schedule that was compiled into the kernel. This meant that, erstwhile utilizing seL4 to enforce the information travel boundaries betwixt applications, developers were required to supply a fixed predetermined magnitude of clip for each domain, for the entire life of the moving system. This strict argumentation made it difficult to apply information travel power successful believe and to support successful SDK-style improvement such as the Microkit.

Proofcraft projected a caller seL4 runtime API (Application Programming Interface) allowing the loading of semi-static domain schedules. This intends that a system with accusation travel protection tin spell done different phases astatine runtime that can fulfill different domain timing requirements. For instance, a footwear shape of the strategy tin person longer clip slices to let virtual machines to start without overrunning their domain clip allocation, and an operational shape of the strategy tin supply shorter clip slices truthful that each domain tin beryllium responsive to extracurricular interaction. Additionally, an SDK-based strategy specified arsenic the Microkit can usage the caller API to group a domain schedule astatine footwear time.

This caller seL4 API is implemented, verified and disposable successful seL4 15.0.0.

June Andronick Keynote astatine CDIS Spring Conference successful Stockholm

On May 21st 2026, CDIS – Swedish investigation Center for Cyber Defense and Information Security – held its spring conference astatine KTH Royal Institute of Technology successful Stockholm.

Proofcraft CEO June Andronick was 1 of the 2 keynote speakers, alongside August Martens from Mistral AI. June gave an overview of general verification for cybersecurity, and participated successful a sheet connected Digital Sovereignty.

Proofcraft presenting astatine the Cyberagentur Milestone Research summit

In April 2026, Germany’s Cyberagentur held a Milestone Research acme to present the advancement and outcomes of its funded programs, including the Ecosystem trustworthy IT investigation programme (ÖvIT), which Proofcraft is a recipient of, partnering pinch Kry10.

Proofcraft’s Chief Scientist Gerwin and Kry10’s Chief Scientist Martin Dehnel-Wild presented the advancement connected the Dyvercon project, to deliver dynamism, performance, and impervious for analyzable cyber-physical systems. In particular, Gerwin reported connected Proofcraft’s activity connected extending the seL4 proofs to support a fixed multikernel configuration, wherever applications can benefit from the usage of aggregate CPU cores for performance, while astatine the kernel level a abstracted lawsuit of seL4 tally connected each core.

Gerwin additionally gave a wide preamble to general verification and overview of its usage successful the existent world.

Proofcraft is simply a proud sponsor of the seL4 acme 2026

Proofcraft is happy to beryllium supporting the 2026 seL4 summit arsenic a Silver sponsor.

The seL4 acme is an yearly world gathering of participants from industry, authorities and universities pinch interests successful the world’s astir highly assured OS kernel. Attendees and presenters see the creators and maintainers of the seL4 exertion specified arsenic the Proofcraft team.

This year’s seL4 acme will beryllium held successful Vancouver, Canada, connected Sep 1-3, 2026.

5 years of Proofcraft. 5 years person to a verified future.

On the 14th of April 2021, we created Proofcraft. Five years later, we are so busy moving for a verified early that we person not posted news for a while.

Much has happened, and much is to come. For now, present are immoderate posts from our back log of news items pinch method highlights that Proofcraft has been delivering.

Firstly, the seL4 proofs are now supported connected 100% of Arm platforms that the kernel tin tally on. With this important advancement towards reducing the reliance on experts, users of seL4 tin now take freely betwixt the supported Arm platforms and ever beryllium judge they usage a verified codification base. This activity is portion of DARPA’s PROVERS program.

Secondly, seL4 connected AArch64 now provably enforces integrity: We person a formal mathematical impervious that the kernel prevents an exertion moving connected apical of seL4 from modifying information without authorisation. And the activity connected security theorems goes on: acknowledgment to continued support from NCSC, we are adjacent to completing the confidentiality property, and pinch that the full information proof stack for the 64-bit Arm architecture.

Much much is happening, pinch 3 ample projects going connected successful parallel, funded by DARPA, Cyberagentur and NCSC respectively. Stay tuned for more!