FlagThis

Abstract

The rapid growth of digital content has made reliable integrity verification increasingly important. Existing solutions rely either on centralized authorities, which introduce trust dependencies and single points of failure, or on decentralized storage systems that incur prohibitive resource overhead. In this paper, we present snaproot , a lightweight system that implements the hash-anchoring paradigm of Haber and Stornetta on the Solana blockchain to provide efficient, decentralized file integrity verification. snaproot generates a SHA-256 hash of a file and stores it immutably on-chain as a permanent reference record. Verification is performed by recomputing the hash and comparing it to the stored value, yielding a deterministic binary outcome. Beyond the basic anchoring mechanism, we describe a fourtier trust architecture comprising three realized tiers user sovereignty through locally generated keys, within-chain immutability through consensus, and cross-fork verifiability and one prospective tier consisting of a planned cross-chain migration mechanism for longterm persistence beyond the lifetime of any single blockchain. We present a formal threat model, a security analysis grounded in the second-preimage resistance of SHA-256, and an empirical evaluation on Solana Devnet across file sizes from 1 KB to 500 MB, with sub-fivesecond confirmation latency on Devnet that supports capture-time anchoring of photographs as a practical workflow for typical network conditions. The system is deployed on Solana Mainnet; a formal characterization under Mainnet load is left to future work. A central conceptual contribution of this work is the explicit structural separation between existence proof the chain-resident, key-independent claim that a file existed at a given time and authorship proof the key-dependent binding between a record and a specific wallet identity. This separation, which is absent or implicit in most prior hash-anchoring designs, allows existence guarantees to survive key loss, organisational change, and provider disappearance, while preserving the ability to make stronger authorship claims where keys are retained. We position snaproot against established hash-anchoring systems (OpenTimestamps, OriginStamp, Chainpoint) and discuss limitations with respect to pre-registration manipulation and AI-generated content.