Why Pre-Loss Documentation Holds Up in Claims Disputes

How SHA-256 hashing, blockchain timestamp finality, and independent verification create evidence that survives hostile review.

This page is the ProofLedger legal admissibility white paper. Save it as a PDF to share with counsel, claims reviewers, or your team.

The Core Problem: Proving When Evidence Existed

In any dispute — insurance, construction, litigation — the value of evidence depends on when it was created. A photograph of a roof taken before a hurricane is powerful evidence. The same photograph, if it cannot be proven to predate the event, is worthless.

Digital files carry metadata (EXIF data, file system timestamps), but this metadata is trivially modifiable. Courts and claims reviewers know this. Opposing counsel will challenge file dates. Carriers will question creation times. Without an independent anchor, the timestamp is just an assertion by the party with an interest in the outcome.

How ProofLedger Solves This

SHA-256 Cryptographic Fingerprinting

When a file is submitted to ProofLedger, a SHA-256 hash is computed. This is a one-way mathematical function that produces a unique 64-character fingerprint. Any change to the file — a single pixel, a single byte — produces a completely different hash. This is not encryption; the original file cannot be reconstructed from the hash.

ProofLedger never sees, stores, or transmits your original files. Only the hash is recorded. Your evidence stays on your devices.

Blockchain Timestamp Anchoring

The hash is then anchored to a public blockchain with a timestamp. This creates an immutable, independently verifiable record that the specific hash existed at a specific point in time.

Polygon anchoring (included in all paid tiers): Fast, cost-efficient. Suitable for routine documentation.
Bitcoin anchoring (Escalation tier): The most secure, battle-tested blockchain. Appropriate for evidence that may face hostile legal review.

Once anchored, the timestamp cannot be altered, backdated, or removed by anyone — including ProofLedger.

Independent Verification

Any party — an opposing attorney, a claims reviewer, a judge — can independently verify a ProofLedger record:

Compute the SHA-256 hash of the original file (using any standard tool)
Look up the hash on the ProofLedger verification page
Confirm the blockchain transaction using any public blockchain explorer

No trust in ProofLedger is required. The verification chain is fully transparent and reproducible.

Legal Authentication Standards

Federal Rules of Evidence — Rule 901

FRE 901(a) requires that evidence be authenticated by "evidence sufficient to support a finding that the item is what the proponent claims it is." ProofLedger addresses this through:

901(b)(1) — Testimony of a witness with knowledge: The person who captured the evidence can testify to its creation, and ProofLedger provides independent confirmation of when the hash was first recorded.
901(b)(9) — Evidence about a process or system: The SHA-256 hashing and blockchain anchoring process can be described as a system that produces accurate results. The mathematics of SHA-256 and the immutability of blockchain records are well-established.

See also: Florida Statute § 90.901 (authentication requirement), which mirrors the federal standard.

Why Blockchain Timestamps Are Stronger Than Server Logs

A company's internal database can be modified by the company. A blockchain cannot be modified by any single party. This distinction matters when the opposing side challenges the credibility of the timestamp provider. ProofLedger's anchors are on public ledgers that ProofLedger does not control and cannot alter.

Key distinction: ProofLedger does not prove authorship, ownership, rights, intent, or truth. It proves that a specific digital fingerprint existed at a specific time. What the file means is a matter for the parties and the tribunal.

Certificate Classes

Standard Proof Certificate (Polygon)

Suitable for routine pre-loss documentation, maintenance records, and inspection reports. Polygon is a well-established public blockchain with fast finality.

Escalation Proof Certificate (Polygon + Bitcoin)

For matters where evidence may face hostile review — contested insurance claims, active litigation, regulatory proceedings. Bitcoin is the most secure, longest-running blockchain and carries the highest evidentiary weight. Escalation certificates are appropriate when the stakes justify the additional anchoring cost.

Survivability: What Happens If ProofLedger Ceases Operations

Every blockchain anchor is a permanent public record. If ProofLedger ceased operations entirely:

Polygon transaction records remain on the Polygon blockchain, queryable through any Polygon explorer
Bitcoin transaction records remain on the Bitcoin blockchain, queryable through any Bitcoin explorer
Anyone with the original file can compute its SHA-256 hash and match it against the on-chain record

ProofLedger is designed so that the evidence outlives the platform. This is an intentional architectural decision, not an afterthought.

How to Obtain ProofLedger Evidence for a Pending Dispute

Create a free account at proofledger.io — no credit card required
Upload your evidence files through the Record Evidence page. Each file receives a proof record with blockchain anchoring.
For litigation-grade evidence, select Bitcoin anchoring (Escalation) to add the strongest available timestamp.
Share the verification URL with opposing counsel, the claims reviewer, or the court. The verification page is public and requires no account.

For team or enterprise needs — multiple inspectors, shared evidence packages, API integration — see Enterprise or contact support.