SkillChain: A Decentralized Framework for Cryptographic Credential Authentication and Immutable Provenance on the Algorand Blockchain

This preprint establishes the initial public disclosure of the SkillChain system architecture.This work presents SkillChain, a decentralized credential verification framework based on cryptographic hashing and blockchain anchoring. The system records a SHA-256 hash of a credential on the Algorand blockchain to provide proof-of-existence while preserving document privacy through off-chain storage. A normalization pipeline enables deterministic verification across document formats, and a decentralized identifier (DID) provenance layer supports issuer attribution. The implementation represents a functional research prototype demonstrating feasibility of independent authenticity verification without direct reliance on institutional communication. This preprint serves as an initial architectural disclosure and foundation for future empirical evaluation.