Descripción
---base: /meta-keywords:meta-viewport: width=device-width, initial-scale=1.0title: Protocol Stack Engineer (80-100%)---Protocol Stack Engineer (80\-100%)==================================Threema 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.We are growing and looking for a new team member to join as a### Protocol Stack Engineer (80\-100%) **Your Role**The protocols underneath all of this are what we're hiring for. You'll 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. **What you'll do*** Design new protocol features and extensions, such as multi\-device sync, group messaging and calls, and write the specifications for them.* Implement protocol logic in and review implementations across our Android, iOS, desktop and web clients.* Model threats and reason through edge cases like message reordering, device loss, malicious servers and compromised keys.* Work with external security researchers and auditors, respond to findings and ship fixes.* Keep backward compatibility for a large installed base while moving the protocol forward.* other engineers and help set standards for how we write and review security\-critical code. **What you bring*** At least 6 years of software engineering, with several years working on network or cryptographic protocols.* A 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.* Experience readi