Location: Remote
Company: Sigma Prime
Sigma Prime is a boutique information security firm providing specialist expertise across blockchain systems and decentralised infrastructure. We are a team of developers, researchers, and security engineers.
Since 2015, we have worked at the forefront of blockchain security, reviewing Layer 1 and Layer 2 protocols, core cryptographic libraries, consensus systems, bridges, staking infrastructure, and advanced cryptographic constructions. We provide security reviews, design consultancy, and research services to leading organisations across the Web3 ecosystem.
We are also the creators and maintainers of Lighthouse, a leading Ethereum consensus client written in Rust and used in production globally. Lighthouse reflects our deep expertise in distributed systems, applied cryptography, and protocol engineering.
Our public audit reports can be found at:
https://github.com/sigp/public-audits/
We are seeking a Cryptographer – Security Engineer to join our security team.
This role is focused on auditing and analysing cryptographic protocols and implementations used in Web3 systems. You will work on cutting-edge distributed systems and zero-knowledge technologies, reviewing both protocol design and low-level implementations.
You will perform in-depth security assessments of:
Elliptic curve cryptography implementations
Pairing-based cryptography
Distributed Key Generation (DKG) protocols
Threshold signature schemes (e.g., FROST)
SNARK and STARK proving systems
KZG commitments and polynomial commitment schemes
Zero-knowledge circuits and proving infrastructure
Consensus-critical cryptographic components
Our engagements often involve reviewing cryptographic libraries but are not specifically limited to only cryptography. There will be ample opportunity to work further through the web3 stack on core node infrastructure, smart contracts, cloud infrastructure and front-ends.
Filecoin – Drand DKG and threshold randomness protocol
Filecoin – Proving Subsystem security review
Ethereum Foundation – c-KZG & go-KZG libraries
Ethereum Foundation – KZG Powers of Tau Ceremony
Ethereum Foundation – BLS Wallet
Lido – BLS Precompile Library
Chainway Labs – Clementine (Bitcoin ↔ Citrea bridge using FROST DKG)
Obol – Charon distributed validator client
Conduct technical security reviews of cryptographic protocols and implementations
Analyse protocol-level designs for soundness and attack surface
Review Rust, Go, and Solidity cryptographic implementations
Identify subtle vulnerabilities in mathematical constructions and real-world implementations
Write clear and precise security reports
Contribute to internal cryptographic research and methodology
Collaborate with protocol teams to improve security and design robustness
Potentially contribute to internal open-source projects such as Lighthouse
Advanced knowledge of applied cryptography
Deep understanding of elliptic curves and finite field arithmetic
Familiarity with pairing-based cryptography and BLS signatures
Understanding of zero-knowledge systems (SNARKs, STARKs, PLONK, etc.)
Experience analysing or implementing DKG or threshold signature systems
Ability to read and reason about academic cryptography papers
Strong systems programming skills (preferably Rust or Go)
Reviewing or building cryptographic libraries
Experience in consensus systems or distributed systems
Formal methods or cryptographic proofs
Experience contributing to open-source cryptographic software
Prior security auditing experience
Most common languages in our engagements:
Rust
Golang
Solidity
Experience in C/C++, Python, or cryptographic DSLs is also beneficial.
Remote-first team
High-calibre technical peers
Opportunity to work on foundational infrastructure securing billions in value
Meaningful impact on the security of global decentralised systems
If you are passionate about applied cryptography and want to secure the next generation of decentralised systems, we would love to hear from you.