Senior Distributed Systems & Cryptography Engineer (contract)

Title: Senior Distributed Systems & Cryptography Engineer Location: 1655 Grant St Concord, CA Duration: 6 months Work Engagement: W2 Work Schedule: 3 days in office/2 days remote Compensation: $70-75/hr is the pay range that the employer reasonably expects to pay for this position Benefits on offer for this contract position: Health Insurance, Life insurance, 401K and Voluntary Benefits Summary: We are building a next-generation Digital Asset Platform focused on solving the “Approval-to-Execution Gap” in institutional finance—ensuring that digital asset transactions are executed only when explicitly authorized by policy, without exposing sensitive cryptographic material to cloud operators or internal actors. This is not a traditional wallet platform. We are designing an institutional-grade Confidential Custody Infrastructure that combines Multi-Party Computation (MPC) with hardware-enforced Confidential Computing (Trusted Execution Environments) to create a “glass vault”—a system where all cryptographic operations are isolated, verifiable, and mathematically secure. We are seeking a core systems engineer with deep experience in distributed systems, cryptography, and secure infrastructure. This role requires close collaboration with technical teams and hands-on ownership of critical platform components. Key Responsibilities: MPC Protocol Implementation: Architect and implement high-performance threshold signature schemes (specifically DKLS23 or similar) for ECDSA key generation and signing. Confidential Computing Architecture: Design and build services that run inside Trusted Execution Environments (TEEs), specifically targeting AMD SEV-SNP and Intel TDX via Confidential Containers (CoCo). Attestation Framework: Implement the RATS (Remote ATtestation procedureS) architecture (RFC 9334) to ensure that no key share is released until the requesting node proves its hardware and software integrity to a Key Broker Service. Hardware Security Integration: Design "Cold Ceremony" workflows that integrate offline hardware tokens as offline Key Encryption Keys (KEKs) for disaster recovery and deep storage. Secure Enclave Development: Write and optimize memory-safe code (Rust/Go) that operates on key material exclusively within encrypted memory regions, ensuring zero leakage to the host OS or hypervisor. Policy-to-Cryptography Binding: Design mechanisms to cryptographically bind business logic approvals (e.g., WebAuthn assertions) directly to the MPC signing session, eliminating the gap between "approval" and "execution". Qualifications: Applicants must be authorized to work for ANY employer in the U.S. This position is not eligible for visa sponsorship. Strong experience in systems-level engineering within distributed environments Proven track record building or operating distributed systems at scale Expert-level proficiency in: Go (orchestration, services) Rust (cryptographic and memory-safe components) Experience working in high-bar engineering environments Strong core engineering fundamentals (data structures, concurrency, systems design) Experience collaborating across engineering teams and influencing technical direction Applied Cryptography Deep experience with threshold cryptography, MPC, or related protocols Ability to implement cryptographic research papers (e.g., GG20) from scratch Confidential Computing Hands-on experience with: AMD SEV-SNP Intel SGX/TDX Confidential Containers (CoCo) Strong understanding of attestation flows, measurements, and memory encryption Attestation & Identity Familiarity with RATS architecture, Key Broker Services (KBS), and Attestation Services Experience integrating OIDC, WebAuthn, or FIDO2 Security Architecture Proven experience designing zero-trust / untrusted infrastructure systems Domain Expertise Experience in digital assets, crypto infrastructure, custody platforms, or high-security fintech environments (preferred over traditional banking) Exposure to CNCF Trustee or similar attestation frameworks