Applied Cryptographer (Bitcoin, Post-Quantum Focus)

Blockstream was founded in 2014 by Dr. Adam Back and a group of fellow cryptographers and engineers passionate about Bitcoin and its potential to change the future of finance. Focusing on building fundamental Bitcoin infrastructure, Blockstream quickly grew into one of the leading technology power houses of the industry.
Our research team sits at the forefront of Bitcoin innovation, aiming to be a trusted, innovative, and impactful force in the space. We advance Bitcoin protocol and application development through cryptographic research, specifications, code, and active technical discussions within the community. We foster a collaborative, quality-focused environment that values deep thinking, long-term impact, and transparent, open-source contributions, empowering each member to contribute optimally.

We are seeking a talented Applied Cryptographer to join our research team and play a key role in our Post-Quantum Cryptography (PQC) initiative. You will be instrumental in researching, evaluating, and implementing post-quantum cryptographic solutions tailored for the unique challenges and opportunities within the Bitcoin ecosystem. This is a chance to contribute significantly to the long-term security and evolution of Bitcoin.

What You’ll Be Doing (Responsibilities):

• Adapt state-of-the-art post-quantum cryptography research to the Bitcoin domain, exploring features particularly relevant for Bitcoin (e.g., threshold signatures, signature aggregation, Taproot tweaking, silent payments, HD wallets).
• Explore, evaluate, and benchmark various approaches for concretely integrating post-quantum schemes into Bitcoin, analyzing their implications.
• Contribute to and review Bitcoin Improvement Proposals (BIPs) and adapt standardized cryptography for use in Bitcoin.
• Implement cryptography for potential usage in Bitcoin, emphasizing performance and correctness.

What We Look For In You (Required Qualifications):

• Deep understanding of cryptographic principles and the ability to apply them to analyze complex technical problems and devise innovative solutions.
• Commitment to high-quality, dependable work, reflected in a strong appreciation for robust and misuse-resistant cryptographic designs.
• A long-term perspective suitable for research and development efforts that may take years to reach fruition.
• Excellent communication skills and a collaborative, team-player attitude.

Nice To Haves (Preferred Qualifications):

• Specific academic or practical experience with post-quantum cryptography.
• Familiarity with Bitcoin and Layer 2’s at the protocol level.
• Previous academic work on cryptocurrencies, digital signatures, zero-knowledge proofs, or other areas of cryptography.
• Proven experience implementing cryptography in practical systems.
• Experience with C or Rust.
• Experience contributing to open-source projects.
• Master's degree or PhD in Computer Science or a related field.