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.
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.
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.
The hash is 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.
Once anchored, the timestamp cannot be altered, backdated, or removed by anyone — including ProofLedger.
Any party — an opposing attorney, a claims reviewer, a judge — can independently verify a ProofLedger record:
No trust in ProofLedger is required. The verification chain is fully transparent and reproducible.
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:
See also: Florida Statute § 90.901 (authentication requirement), which mirrors the federal standard.
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.
Suitable for routine pre-loss documentation, maintenance records, and inspection reports. Polygon is a well-established public blockchain with fast finality.
For matters where evidence may face hostile review — contested insurance claims, active litigation, regulatory proceedings. Bitcoin is the most secure, longest-running blockchain. Escalation certificates are appropriate when the stakes justify the additional anchoring cost.
Every blockchain anchor is a permanent public record. If ProofLedger ceased operations entirely:
ProofLedger is designed so that the evidence outlives the platform. This is an intentional architectural decision.
For team or enterprise needs — multiple inspectors, shared evidence packages, API integration — see Enterprise or contact support.
Dual-chain anchoring for claims adjusters, attorneys, forensic engineers, and risk managers. Free tier includes 5 proofs — no credit card required.
