Staff / Principal Cryptographer (IC)

Company: X 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 us: The company is the digital-asset custody and infrastructure platform for the GCC. We hold institutional crypto safely, settle transactions across chains, and expose all of that as a developer API and a regulated-grade institutional console. Why this role exists A custody platform either trusts its MPC scheme or it should not exist. We have shipped a working TSS stack with the founding engineering team. We now need a research-grade specialist to own scheme selection, audit response, signing-protocol evolution, post-quantum readiness, and the cryptographic hard-facts of the platform from the inside. This is not a generic blockchain engineer who applies primitives. This is a practicing cryptographer who designs them, reviews them, and ships them. The role You will own the cryptographic core of Company’s custody platform: Scheme ownership. Select, justify, and evolve the MPC / TSS scheme family we run in production (CGGMP21, FROST, GG18 / GG20, lattice variants, future post-quantum threshold schemes). Protocol reviews. Author and shepherd scheme-review documents. Sit in audit conversations with Trail of Bits, NCC Group, Zellic, or equivalent. Production implementation. Read and write Rust and Go cryptographic code. Pair with the custody engineering team on signing-service performance, share generation, key rotation, and recovery flows. Incident response. When a paper, advisory, or competitor disclosure changes our threat model, you write the response and propose the fix. External representation. Speak at IACR venues, RWC, Real World MPC, ZKProof. Publish work that the company allows you to publish. Internal teaching. Lift the cryptographic literacy of the engineering organization. Run paper-reading sessions. Mentor IC engineers who want to grow into cryptographic specializations. You are not the entire cryptography team. You are the first dedicated cryptographer. Inside 18 to 24 months we expect to grow this function to a small team and you will hire the next people. Must-haves 8-plus years of applied cryptography practice, with at least 4 years on threshold signing, MPC, secret sharing, or related primitives shipped in production at a regulated entity. Hands-on with at least one of: GG18, GG20, FROST, CGGMP21, DKLs23, BLS threshold, lattice-based threshold (Raccoon, Sparkle, equivalent), or a comparable scheme family. You have implemented it, not just read the paper. Production code in Rust or Go. Not just research code. Mainline branches that hold real customer assets. Public technical artifact. At minimum one of: an IACR ePrint, RWC / CRYPTO / EUROCRYPT / ASIACRYPT talk, a maintainer role on an open-source MPC library (cggmp21, multi-party-ecdsa, ZKP libraries, lattice libraries, equivalent), or a public scheme-review writeup. Has been through one regulated-audit cycle as the cryptography-side owner. SOC 2, NYDFS DFS Part 500, FCA, MAS, VARA, OCC, FINMA, or equivalent. Communicates research clearly to engineers who are not cryptographers. You can write a one-page explainer of a primitive that a Senior IC will internalize in 30 minutes. English fluency. 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 point to. Experience reviewing or contributing to NIST submissions (post-quantum signature competition, multi party threshold cryptography call). Open-source maintainer credentials on cggmp21, multi-party-ecdsa, libthreshold, mpc-lib, FRESCO, sl crypto, dkls23, or equivalent. Has co-designed a scheme that was implemented by a third party. Comfort with lattice cryptography and post-quantum threshold variants. This is not the right role if "Blockchain engineer" with no published cryptography work. Wrong specialism. ZK-only background with no MPC / TSS experience. We touch ZK in narrow places but the core function is threshold signing. Hash-and-sign Solidity developer with no protocol-level cryptography depth. Founder of a failed Layer-1 chain looking for a Chief Scientist seat. Currently subject to a non-compete that blocks custody / MPC work for more than 6 months.