pThreema is the world’s best-selling secure messenger for both private users and businesses. Since 2012, we have been working tirelessly to ensure that our users can communicate freely without worrying about their privacy. Our growing user base includes millions of private customers and thousands of businesses and organizations from all over the world. /ppWe are growing and looking for a new team member to join as a Protocol Stack Engineer (80–100%). /ph3Your Role /h3pThe protocols underneath all of this are what we’re hiring for. You will design, implement, and maintain the cryptographic protocols that carry every Threema message, including Ibex, our forward-secrecy protocol. Your work will be read by our own engineers and also by outside researchers, auditors, and curious users. We expect it to hold up to that. /ph3What You Will Do /h3ulliDesign new protocol features and extensions, such as multi-device sync, group messaging, and calls, and write the specifications for them /liliImplement protocol logic in Rust and review implementations across our Android, iOS, desktop, and web clients /liliModel threats and reason through edge cases like message reordering, device loss, malicious servers, and compromised keys /liliWork with external security researchers and auditors, respond to findings, and ship fixes /liliKeep backward compatibility for a large installed base while moving the protocol forward /liliMentor other engineers and help set standards for how we write and review security-critical code /li /ulh3What you bring /h3ulliAt least six years of software engineering, with several years working on network or cryptographic protocols /liliA solid grasp of applied cryptography: you know how authenticated encryption, key exchange, forward secrecy, and post-compromise security work, and where implementations usually go wrong /liliExperience in reading and writing protocol specifications precise enough for someone else to implement from /liliStrong skills in at least one systems language; Rust is a plus /liliCare about the details: in this job, a missing length check is a vulnerability /li /ulh3Nice to Have /h3ulliExperience with formal analysis tools such as Tamarin, ProVerif, or TLA+ /liliFamiliarity with the Signal protocol, MLS, or the Noise framework /liliPublished research, CVEs, audit reports, or open-source contributions in security /liliBackground in mobile platforms and their constraints, such as push delivery, background limits, and battery use /li /ulh3Experience with AI Tools: /h3ulliYou’re familiar with current frontier AI models and use them as a productivity multiplier in design work as well as in coding, for example, to review specification drafts, survey recent literature, or poke holes in a protocol design /liliWhatever tools you use, the outcome is yours; AI can draft and suggest, but the person accountable for a protocol that holds is you /li /ulh3Soft Skills: /h3ulliStrong sense of responsibility, precise way of working /liliYou can write a protocol specification that someone else can implement, and explain trade-offs to people who are not protocol specialists /liliPragmatic judgment about when a design is good enough to ship and when it is not /liliWillingness to have your own designs picked apart, and to pick apart other people’s with care /liliGood written and spoken German and English (at least B2) /li /ulh3What We Offer /h3ulliA young, motivated team with straightforward communication /liliFlexible working hours, option to work from home up to two days per week /liliOption to work from anywhere for two weeks per year /liliOption to take unpaid leave /liliYou can choose your own hardware (macOS or Linux) /liliPublic transportation discount or parking space (electric car charging available) /liliFree use of fitness room, including a fitness trainer once a month /liliProfessional massage once a month /liliInternal German or English courses /liliA great coffee machine ;-) /liliRegular company events and aperitifs /liliThe good feeling of contributing to the effective protection of the privacy of millions of people /li /ulpPlace of work: Pfäffikon SZ (Greater Zurich Area) /ppStart date: Immediately or by agreement /ppHave we sparked your interest? /ppWe believe that diverse teams build better products. We welcome and encourage applications from people of all backgrounds, and perspectives. Your unique experience is an asset, and we’d love to hear from you. /p #J-18808-Ljbffr
Protocol Stack Engineer (80–100%) Arbeitgeber: Threema
pThreema ist ein hervorragender Arbeitgeber, der seinen Mitarbeitern die Möglichkeit bietet, in einem dynamischen und innovativen Umfeld zu arbeiten, das sich auf die Gestaltung sicherer Kommunikationslösungen konzentriert. Mit flexiblen Arbeitszeiten, Fitnessangeboten und einer kollaborativen Teamkultur fördert pThreema nicht nur die berufliche Entwicklung, sondern auch das persönliche Wohlbefinden seiner Mitarbeiter. Die Arbeit in der Schweiz bietet zudem eine hohe Lebensqualität und Zugang zu einer inspirierenden Umgebung für kreative Köpfe.
