Semih Civelek

Privacy & payment protocol engineer. Based in Turkey.

I design and ship production systems at the intersection of zero-knowledge proofs, fully homomorphic encryption, and programmable payments.

My work lives where cryptography meets payments. I build protocols that keep balances, orders, and identities private by default while keeping settlement, liquidity, and attribution verifiable.

GitHub @Himess__semihcvlk53@gmail.com

Featured Work

All projects

GhostLend

Live

Confidential lending & leverage, computed on ciphertext

Zama Developer Program — Builder Track Winner

Borrow, leverage, and net lending positions with the amounts, the debt, and even the leverage ratio encrypted end-to-end. Built on Zama FHEVM, live on Sepolia — no plaintext position ever touches the chain.

SolidityFHE (fhEVM)ERC-7984Chainlink

GhostRail

Live

Confidential lending on Circle's Arc

A confidential lending layer for Arc: supply into public Morpho/Aave-style venues across USDC, ETH, BTC, EURC, and tokenized treasury while keeping your position private — only the net of each batch ever touches the public venue. Plain Solidity, USDC-native, live on Arc testnet, architected for Arc's TEE Privacy Sector.

SolidityArcCircle CCTPUSDC

MARC Protocol

Live

The privacy layer for agent payments

Zama Developer Program — Builder Track Winner

FHE-encrypted tokens, agent identity, and escrow-based commerce for autonomous AI agents. Eight contracts on Sepolia, ten integration plugins, three ERC standards (7984, 8004, 8183).

SolidityFHE (fhEVM)x402MPP

MixVM

Deployed

Cross-chain private USDC

Zero-knowledge privacy pool for USDC with LayerZero V2 messaging and Circle CCTP V2 bridging. Poseidon + Merkle + Groth16 proofs plus ECDH stealth addresses.

SolidityCircomGroth16LayerZero V2

Roil

Live

Privacy treasury on Canton Network

Feature-complete privacy treasury with a custom wallet (Passkey, Google, Email), treasury swap AMM, whitelist, DCA, and governance, all on Canton's privacy-by-default ledger.

DamlCantonNext.jsTypeScript

PrivAgent

Live

Privacy-preserving x402 on Base mainnet

Production x402 payment protocol with privacy features, live on Base mainnet. ERC-8021 builder-code attribution, 282 tests, end-to-end verified.

Solidityx402BaseTypeScript

Pendex

Shipped

FHE-powered dark pool for pre-IPO leveraged trading

Zama Developer Program — Builder Track Winner

Zama Developer Program winning dark pool. Encrypted order book for pre-IPO equity with leverage, cleared on-chain without revealing positions.

SolidityfhEVMFHETypeScript

CityPulse

Shipped

Per-API nanopayment monetization for municipal traffic

Submission-ready Circle × Arc hackathon entry. Per-API nanopayments for municipal traffic data, 3D MapLibre navigation, and an 80-vehicle Istanbul fleet simulation.

Next.jsSolidityArcCircle Nanopayments