A public adjuster gets called in on a commercial property claim three weeks after a storm. The insured has photos of the roof condition taken before the event. Timestamps in the file metadata put them eight months prior. The carrier is skeptical. And without something more than metadata, it has good reason to be.

The carrier's position: metadata is not proof. It's not wrong.

A JPEG timestamp is a field in the file header. Anyone with basic software can change it. Courts know this.

Blockchain timestamping for pre-loss documentation exists to close this gap. ProofLedger anchors a SHA-256 hash of each file to two public blockchains at the moment of capture. Polygon confirms the record instantly. Bitcoin processes a daily batch with merkle proofs. The original files never leave the device. What lands on-chain is a cryptographic fingerprint tied to a specific point in time.

This is what temporal verification looks like in practice. A risk manager documents a property in January, each photo anchored as it's captured. The blockchain entry exists before any loss occurs. Months later, a storm claim comes in. The property manager has those January photos, and with them, blockchain-anchored timestamps confirming the capture date on two independent public ledgers. That's a materially different evidentiary position than metadata alone.

The chain-of-custody gap in digital evidence authentication isn't hypothetical. It's a recurring issue in commercial property and casualty litigation. Defense counsel has learned to challenge file metadata as a timing source, and carriers increasingly scrutinize provenance of photos, inspection reports, and condition records. Courts can authenticate blockchain records under FRE 901(b)(9), which covers evidence produced by a process that generates an accurate result. This requires a technical foundation, typically through certification explaining how the anchoring process works. For machine-generated records, FRE 902(13) allows authentication through written certification without live witness testimony.

An opposing party challenging a blockchain-anchored timestamp has to explain why two independent public ledger records are wrong. That's a harder argument than pointing to a file header that anyone could have modified.

Evidence packs organize anchored files by case, claim, or matter, each with a loss date, pre/post indicators, and a verification record exportable for counsel or carrier review. The structure maps to how adjusters and attorneys actually build a file.

Chain-of-custody documentation built on blockchain anchoring isn't a replacement for thorough evidence collection. It's the layer that makes the timing of that collection independently provable when metadata alone won't hold up.

Anchor before the loss, not after. Risk documentation, not claim documentation.