Senior Network Cryptography Engineer- 3289

Senior Network Cryptography Engineer

Job Description:

A leading company in digital privacy , security and performance solutions field is looking for a Senior Software Engineer with expertise in networking, cryptography, tunneling protocols, and anti-censorship tools. This role requires deep technical knowledge of circumvention techniques and obfuscation methods, along with the ability to work with low-level programming languages to develop and modify tools. The ideal candidate will be proficient in Linux-based systems, possess a strong understanding of evolving censorship tactics, and be able to collaborate with diverse global communities while maintaining a strong awareness of the legal and socio-political contexts surrounding censorship.

Key Responsibilities:

1. Deep Knowledge of Networking:

• TCP/IP: Expertise in the fundamentals of internet protocols, including IP addressing, routing, and traffic management.
• DNS: Understanding DNS resolution and how it can be manipulated or intercepted for censorship.
• VPN Protocols: Knowledge of VPN technologies such as Lightway, OpenVPN, L2TP, PPTP, WireGuard, and IPSEC.
• Proxy Technologies: Experience in configuring and managing proxies such as SOCKS, HTTP, and other types.
• Deep Packet Inspection (DPI): Knowledge of DPI techniques and methods to bypass or evade detection.

1. Cryptography:

• Public and Private Key Infrastructure (PKI): Understanding the fundamentals of PKI systems for encryption and secure communication.
• TLS: Proficiency in Transport Layer Security (TLS), particularly (D)TLS 1.3, and an understanding of its vulnerabilities.

1. Tunneling Protocols:

• Expertise in tunneling protocols such as SSH tunneling, stunnel, and other tools used to disguise and encrypt traffic.

1. Knowledge of Circumvention Tools:

• Tor: In-depth knowledge of the Onion Router (Tor), its architecture, functionality, and vulnerabilities.
• Psiphon: Familiarity with Psiphon, a tool specifically designed to bypass censorship.
• Shadowsocks & ShadowsocksR: Experience with proxy tools used for circumvention, particularly in regions like China.
• Pluggable Transports: Expertise in technologies that alter traffic appearance to avoid censorship detection.

1. Traffic Obfuscation:

• Ability to implement techniques that mask or morph traffic to evade detection and blocking by censorship systems.

1. Monitoring and Analysis:

• Network Analysis Tools: Proficiency with tools like Wireshark, tcpdump, and other network diagnostic tools.
• Traffic Fingerprinting: Understanding how traffic patterns can be identified and how to mitigate fingerprinting efforts.

1. Infrastructure:

• Cloud Platforms: Experience using cloud platforms like AWS, Google Cloud, and Azure to rapidly deploy proxy and VPN servers.
• Content Distribution Networks (CDNs): Knowledge of using CDNs to bypass network restrictions and enhance service availability.

1. Operating Systems:

• Linux: Proficiency with Linux, as the majority of our systems run on Linux servers.
• Mobile Operating Systems: Familiarity with mobile OS like Android and iOS for working with mobile-specific circumvention tools and understanding their limitations.

1. Programming and Scripting:

• Proficiency in programming languages such as Python, C, and Rust for creating custom solutions and modifying existing tools.
• A strong interest in learning new programming languages and frameworks.

1. Legal and Socio-Political Awareness:

• Understanding the legal and ethical implications of anti-censorship work across different jurisdictions.
• Awareness of socio-political environments and challenges, and the ability to navigate these issues while developing solutions.

1. Adaptive Thinking:

• Continuously staying informed about new censorship techniques and finding innovative ways to counteract them.
• Proactively developing and testing new circumvention strategies as censorship evolves.

1. Collaboration and Communication:

• Engaging with global communities to share knowledge, gather intelligence, and develop shared tools for censorship circumvention.
• Collaborating with interdisciplinary teams to develop and deploy effective anti-censorship solutions.

Qualifications:

• Bachelor's or Master's degree in Computer Science, Network Engineering, Cryptography, or a related field.
• 5+ years of experience in software engineering, network security, or a similar technical field.
• Proven experience with VPNs, proxies, and censorship circumvention tools.
• Strong programming skills in Python, C, Rust, or similar languages.
• Extensive experience with Linux-based systems and server management.
• In-depth knowledge of networking protocols, traffic analysis, and obfuscation techniques.
• Familiarity with legal, ethical, and political issues surrounding censorship and privacy.
• Excellent communication and collaboration skills, with a strong ability to work in a remote, diverse team environment.

Preferred Qualifications:

• Experience working with distributed systems, cloud infrastructures, or internet governance.
• Familiarity with privacy-enhancing technologies and the open internet movement.
• A proactive mindset with the ability to think creatively and solve complex technical problems.