Cryptography and Systems Researcher

About the role

This position centers on advancing Bitcoin protocols through cryptographic research and engineering. The work involves designing and analyzing various cryptographic schemes, including BLS proof-of-stake commitments and zero-knowledge proof systems for Bitcoin anchoring. A key part of the role is formalizing consensus protocols to ensure security, focusing on properties like Byzantine fault tolerance and commitment finality, supported by rigorous threat modeling.

The role also requires developing and validating cryptographic implementations, collaborating with the protocol team on integrations, and verifying specifications against code. Building simulations and prototypes in Rust or C++ is essential for validating protocol designs under adversarial conditions and analyzing safety and liveness properties. Success in this role means identifying vulnerabilities through formal cryptographic security analysis, including game-theoretic attack analysis and stress-testing.

Char Network Labs operates as a small, collaborative team pushing the boundaries of Bitcoin R&D and infrastructure. The company is developing a proof-of-stake application coordination protocol built on Bitcoin, aiming to enable the next generation of Bitcoin layer two solutions. This involves anchoring data into Bitcoin using cryptographic proofs and economic guarantees, blending deep protocol expertise with creative problem-solving.

The salary for this position ranges from $80,000 to $250,000 USD.

Skills that matter here

• cryptography: This role requires designing, analyzing, and implementing various cryptographic schemes for Bitcoin protocols.
• distributed systems: The position involves applying distributed systems theory to formalize and secure consensus protocols.
• Rust: Candidates will use Rust to build simulations and prototypes for validating cryptographic protocol designs.
• C++: C++ is another language used for developing simulations and prototypes to test cryptographic protocols.

Who this role suits

• You are someone who thrives on moving between theoretical research and practical implementation.
• You possess a deep understanding of cryptographic principles and distributed systems theory.
• You are adept at analyzing and breaking adversarial cryptographic protocols or consensus systems.
• You can clearly communicate complex cryptographic ideas to both technical and non-technical audiences.

From the employer

What You’ll Do

• Design and analyze cryptographic schemes: BLS proof-of-stake commitments, signature aggregation protocols, hash-based accumulator designs, and zero-knowledge proof systems for Bitcoin anchoring.
• Formalize consensus protocols for protocol security: fork-free properties, Byzantine fault tolerance guarantees, and commitment finality, with rigorous threat modeling and adversarial analysis.
• Develop and validate cryptographic implementations: work with the protocol team to guide BLS Purify integration, verify protocol specifications against implementation, and conduct security reviews.
• Build simulations and prototypes in Rust or C++ to validate cryptographic protocol designs under adversarial conditions: analyze safety/liveness properties and attack resilience.
• Conduct formal cryptographic security analysis: threat modeling, game-theoretic attack analysis, and stress-testing through simulation and fuzzing to identify vulnerabilities before shipping.

What We’re Looking For

Must-Haves

• Deep expertise in applied cryptography: signature schemes, commitment schemes, zero-knowledge proofs, or cryptographic protocol design.
• Expert-level understanding of distributed systems theory: BFT consensus, fork-free protocols, Byzantine fault tolerance, and formal safety/liveness analysis.
• Strong programming skills in Rust or C++ (or equivalent systems languages).
• Experience designing, analyzing, or breaking adversarial cryptographic protocols or consensus systems.
• Ability to move between theory and practice: formal reasoning, mathematical modeling, and implementation.
• Exceptional communication skills—you can explain complex cryptographic ideas clearly to both researchers and engineers.

Nice-to-Haves

• PhD or equivalent research experience in cryptography, distributed systems, or a related field.
• Prior contributions to Bitcoin, Ethereum, or other consensus-critical software.
• Experience with formal verification, model checking, or advanced testing frameworks.
• Published papers, technical reports, or BIPs in cryptography or distributed systems.
• Understanding of Bitcoin primitives: taproot, timelocks, covenant designs, transaction scripting.
• Experience with game-theoretic analysis or mechanism design (helpful for understanding protocol incentives).
• Strong open-source collaboration background.