Staff Cryptographer

Location: Remote-friendly globally (UTC-3 to UTC+5 for working overlap).
Reports to: Head of Engineering (once hired). Co-Founder / CTO.
Type: Full-time. Individual Contributor.

About the role:
The company is a digital-asset custody and infrastructure platform for the GCC, focusing on safely holding institutional crypto, settling transactions across chains, and providing a developer API along with a regulated-grade institutional console. This role exists to ensure the security and integrity of our custody platform's cryptographic core. We are seeking a research-grade specialist who will be responsible for scheme selection, audit response, signing-protocol evolution, post-quantum readiness, and the cryptographic fundamentals of the platform. You will not just be applying cryptographic primitives; you will be designing, reviewing, and delivering them.

Responsibilities:

• Scheme ownership: Select, justify, and evolve the MPC / TSS scheme family in production (CGGMP21, FROST, GG18 / GG20, lattice variants, future post-quantum threshold schemes).
• Protocol reviews: Author and shepherd scheme-review documents; participate in audit conversations with entities like Trail of Bits, NCC Group, and Zellic.
• Production implementation: Write and read Rust and Go cryptographic code; collaborate with the custody engineering team on signing-service performance, share generation, key rotation, and recovery flows.
• Incident response: Draft responses and propose fixes when changes in our threat model arise due to papers, advisories, or competitor disclosures.
• External representation: Speak at events like IACR, RWC, Real World MPC, and ZKProof; publish work that the company permits.
• Internal teaching: Enhance the cryptographic literacy within the engineering organization, run paper-reading sessions, and mentor engineers interested in cryptographic specializations.
• Team growth: You will be the first dedicated cryptographer, and within 18 to 24 months, you will help grow this function into a small team.

Must-haves:

• 8-plus years of applied cryptography practice, with at least 4 years focused on threshold signing, MPC, secret sharing, or related primitives deployed in a regulated entity.
• Hands-on experience with at least one of the following: GG18, GG20, FROST, CGGMP21, DKLs23, BLS threshold, lattice-based threshold (Raccoon, Sparkle or equivalent); you should have implemented it, not just read about it.
• Proficient in production code in Rust or Go, with experience in mainline branches that manage real customer assets.
• Documented public technical artifact such as an IACR ePrint, presentations at RWC / CRYPTO / EUROCRYPT / ASIACRYPT, a maintainer role in an open-source MPC library, or a public scheme-review writeup.
• Previous experience going through a regulated-audit cycle as the cryptography-side owner (SOC 2, NYDFS DFS Part 500, FCA, MAS, VARA, OCC, FINMA, or equivalent).
• Ability to clearly communicate technical research to non-cryptographers, including crafting one-page explainers of primitives digestible within 30 minutes.
• Fluency in English, both written and verbal.

Nice-to-haves:

• PhD in cryptography from a recognized program.
• Co-authorship on a paper that has been cited by a deployed system you can reference.
• Experience in reviewing or contributing to NIST submissions related to post-quantum signature competition or multi-party threshold cryptography call.
• Credentials as an open-source maintainer for projects like cggmp21, multi-party-ecdsa, libthreshold, mpc-lib, FRESCO, sl crypto, dkls23, or equivalent.
• Experience co-designing a scheme implemented by a third party.
• Familiarity with lattice cryptography and post-quantum threshold variants.

This is not the right role if:

• You are a "Blockchain engineer" with no published cryptography work.
• You have a ZK-only background without MPC / TSS experience; while we touch ZK in specific areas, the core function is threshold signing.
• You are a hash-and-sign Solidity developer without protocol-level cryptography depth.
• You are currently subject to a non-compete that prohibits custody / MPC work for more than 6 months.