Protocol Engineer

Role Summary

We are seeking a Protocol Engineer with an expertise in cryptography,

blockchain, zero-knowledge systems, and Rust.

The role focuses on designing, implementing, optimizing and actualizing the core

proving systems, circuits, cryptographic primitives, and protocol logic powering

Nullmask.

Responsibilities

• Assist with design and implementation of zkSNARK-based components and
• proving systems (Noir and Rust, currently we use UltraHonk, we will probably
• switch to Jolt)
• Develop cryptographic primitives and libraries in Rust
• Translate research into specification for developers
• Implement Solidity smart contracts for on-chain protocol components
• Optimize zk-circuits and E2E protocol latency
• Investigate overall protocol privacy and possible attack vectors
• Conduct security reviews and cryptanalysis of critical components
• Contribute to documentation, specifications, and protocol design
• Collaborate across research, backend, and product teams

Protocol Engineer Required Skills

Mathematics & Algebra

• Solid understanding of linear algebra, finite fields arithmetic, field extensions,
• polynomial interpolation
• Elliptic curve fundamentals (group law, curves, scalar arithmetic)
• Basic knowledge of curve cycles and pairings

Computational Algebra

• Polynomial algorithms (FFT/NTT)
• Big integer arithmetic (Montgomery, Karacuba)
• Basic computational algebra concepts (symbolic computation)

Cryptography

• Solid knowledge of provable security & reductions
• Commitment schemes (Pedersen, KZG, IPA, Merkle)
• Signature schemes (ECDSA, Schnorr, BLS)
• Hash functions (Poseidon2, Keccak, SHA-256, etc.)
• Merkle trees (sparse, incremental)
• Symmetric & asymmetric cryptography
• Elliptic-curve cryptography fundamentals and applications

Zero-Knowledge Proofs

• Solid understanding of zkSNARK
• Familiar with Fiat–Shamir transformation
• Polynomial commitments, IOPs, ZKG
• Protocol Engineer 2Familiarity with basic differences between:

Groth16

Plonk / Plonkish

Plonky2

zkSTARKs & FRI

• Basic understanding of concept of recursive proofs:

Accumulation schemes (Halo2, UltraHonk)

Folding schemes (Nova, HyperNova, CycleFold)

Familiarity with zkVMs / zkEVMs

Arithmetization

• Solid understanding of circuit design and arithmetization

range checks, custom gates, lookup tables

• Basic understanding of R1CS, Plonkish, AIR

Blockchain & Smart Contracts

• Solid understanding of Ethereum:

Transaction format, gas model, EVM architecture

Precompiles, storage, calldata, logs

Token wraping

L2 solutions (zkRollups, optimistic rollups, validiums)

• Bridges (native, Wormhole), message passing (e.g. LayerZero)
• Liquidity pools and AMM fundamentals

Privacy protocols (Zcash, Monero, Tornado, Railgun):

Nullifiers, Merkle trees, UTXO model, inclusion proofs

• Basic understanding of compliance in privacy-preserving systems

Programming & Tooling

• Advanced proficiency in Rust (async, traits, borrowing, performance)
• Basic proficiency in JavaScript/TypeScript
• Familiarity with Solidity
• Git & GitHub workflows

Nice to Have

• Experience with Arkworks, Halo2, Plonky2, Circom, or Nova
• Experience with zkVMs (Risc-0, SP1, Jolt, Cairo, Lurk)
• Experience building privacy systems (mixers, stealth addresses, MPC)
• Strong background in security audits or protocol design
• Systems engineering (Linux, networking, low-level optimization)
• Experience contributing to open-source cryptography projects
• Understanding of account abstraction (EIP-4337) and private wallets

Why Join Nullmask

• Work on cutting-edge cryptography and ZK systems
• Direct collaboration with senior cryptography talent
• Greenfield protocol design — minimal legacy constraints
• High personal impact on a core privacy technology
• Opportunity to shape a new privacy standard for Ethereum