Senior Protocol Stack Engineer (Cryptography & Rust)

Startupvalleys; Freienbach; Híbrido; CHF 140 000 - 190 000; Tempo integral

Vantagens oferecidas por esta oferta de emprego

Flexible hours

Work from home (up to 2 days/wk)

Work from anywhere 2 weeks/yr

Own hardware: macOS or Linux

Public transport discount

Free fitness room and trainer

Monthly professional massage

German/English courses

Coffee machine and events

Impact privacy for millions

Resumo da oferta

Threema in Pfäffikon SZ is looking for a Protocol Stack Engineer (80–100%). You will design, implement, and maintain cryptographic protocols that carry every Threema message, including Ibex, ensuring forward secrecy and backward compatibility across platforms.

You will work with external researchers and auditors, address findings, and ship fixes. You will mentor engineers, set standards for secure development, and collaborate across Android, iOS, desktop, and web clients.

Qualificações

• Six years of software engineering, with several years on network or cryptographic protocols.
• Strong grasp of applied cryptography: authenticated encryption, key exchange, forward secrecy, post-compromise security.

Responsabilidades

• Design new protocol features and extensions (multi-device sync, group messaging, calls).
• Implement protocol logic in Rust for Android, iOS, desktop, and web clients.
• Model threats and edge cases (reordering, device loss, malicious servers, compromised keys).
• Collaborate with external security researchers and auditors; respond to findings and ship fixes.
• Maintain backward compatibility while progressing the protocol.
• Mentor engineers and help set security coding standards.

Conhecimentos

Network protocols

Applied cryptography

Rust

Protocol specifications

German

English

Ferramentas

Tamarin

ProVerif

TLA+

Descrição da oferta de emprego

Threema in Pfäffikon SZ is looking for a Protocol Stack Engineer (80–100%). You will design, implement, and maintain cryptographic protocols that carry every Threema message, including Ibex, ensuring forward secrecy and backward compatibility across platforms.

You will work with external researchers and auditors, address findings, and ship fixes. You will mentor engineers, set standards for secure development, and collaborate across Android, iOS, desktop, and web clients.