Optimizing Zero-Knowledge Proofs For Soulbound Token-Based Academic Authentication On Resource-Constrained Devices

Abstract

The transition toward the Web3 ecosystem shifts digital identity management from centralized authorities toward user-controlled decentralized infrastructures. However, blockchain-based academic credentials implemented through Soulbound Tokens (SBTs) may expose privacy risks because credential activities remain publicly observable. This study presents an academic authentication framework that integrates the ERC-5192 Soulbound Token standard with Groth16 zk-SNARKs implemented using Circom, SnarkJS, and client-side WebAssembly (WASM). The framework combines Merkle-tree membership validation and a nullifier mechanism to support privacy-preserving credential verification and replay resistance. Experimental evaluation was conducted under controlled conditions using a Samsung Galaxy A24 mobile device and the Ethereum Sepolia Testnet. Across 50 authentication trials, the prototype achieved a 100% authentication success rate. The measured mean authentication latency was 6.30 s, consisting of wallet connection (0.50 s), witness generation (1.00 s), proof generation (4.59 s), and smart contract verification (0.21 s). These results demonstrate the feasibility of browser-based privacy-preserving academic credential verification under the evaluated experimental configuration, while broader device and deployment validation remain necessary for large-scale implementation.