Verifying Insurance Claim Documents

Verifying Insurance Claim Documents With Hashes

You can verify that an insurance claim document has not changed since a particular moment by comparing its SHA-256 hash with a hash recorded earlier. A blockchain timestamp makes that earlier record independently checkable. What this method cannot do is show that the document was truthful, or genuine when it was first created. It answers “is this the same file?”, not “is this file honest?”.

That distinction matters because claim files now arrive as PDFs, photos, invoices and estimates that are easy to edit. This guide explains what hash comparison establishes, how to run the check step by step, and where other fraud-detection methods must take over.

Two different questions about a claim document

Reviewers of claim documents usually need to answer one of two questions.

Integrity: Is the file in front of me byte-for-byte identical to the file that existed at an earlier point?

Authenticity: Was that earlier file genuine, accurate and created by the person who says they created it?

A hash comparison answers only the first question. Forensic analysis, source checks, claimant interviews and repair-shop verification address the second. Treating them as one question is the most common way a timestamp ends up being over-trusted.

Why integrity checks matter more now

Insurers report that editing claim documents has become cheaper. Verisk, an insurance data and analytics provider, wrote in April 2025 that generative AI can produce convincing medical reports, invoices and accident photos in seconds. The same article describes “shallowfakes,” which are small edits to genuine documents, and notes that minor adjustments often pass undetected. This is a vendor’s description of the risk, not an independent measurement.

A May 2026 SAS press release makes a related point about images. It cites a survey by the Association of Certified Fraud Examiners and SAS in which only 7% of anti-fraud professionals said their organization was more than moderately prepared to detect or prevent AI-driven fraud. Treat that figure as a third-party claim from a vendor that sells detection tools.

Detection tools look for signs of manipulation. Verisk describes document forensics that spot mismatched fonts, altered dates or overlapping text in PDFs. A hash comparison works differently. It does not look for signs of editing at all. It checks whether a file matches a fingerprint taken earlier, and it can only do so if an earlier fingerprint exists.

What a hash comparison establishes

A hash function converts a file into a short, fixed-length string. NIST’s Secure Hash Standard (FIPS 180-4) specifies SHA-256 and describes the output as a message digest. If the file is altered, even by one character, the digest changes, so a mismatch shows the file is not the one that was fingerprinted. A match shows the file is identical to the fingerprinted version.

For US litigation, hash values have an established role in authenticating electronic data. Federal Rule of Evidence 902(14), effective 1 December 2017, allows data copied from an electronic device, storage medium or file to be authenticated by a “process of digital identification,” shown through a certification by a qualified person. The Advisory Committee notes refer to hash values as the usual method, according to the American Bar Association’s summary of the rule.

Three qualifications apply.

* Rule 902(14) concerns authenticating a copy by certification. It does not make a hash record automatically admissible, and it does not address hearsay.

* The ABA summary notes that a certification authenticates the copy made for court. It has no bearing on whether the original was altered before the copy was made. A hash recorded when the file was first stored can show whether the file is unchanged since then, which may go to the weight of the evidence.

* A Certelo certificate is not a certification by a “qualified person.” Whether it supports a particular proceeding is a question for counsel in the relevant jurisdiction.

That second point is the practical reason to fingerprint claim documents early. A hash taken at intake or before submission gives a later reviewer something to compare against.

How a blockchain timestamp adds an independent time reference

A hash on its own proves nothing about timing, because whoever holds the file can compute a hash at any time. A timestamp ties the hash to an external time reference.

Certelo works as follows, based on its current website and compliance documentation:

* The file stays on the user’s device. Certelo calculates the SHA-256 fingerprint locally in the browser, and the original file is not uploaded to create the proof.

* The fingerprint is recorded on the Electra Protocol blockchain.

* The result is a PDF certificate. Anyone can check the record using the original file, the SHA-256 hash or the certificate ID, without an account.

* The record shows that a file with that exact fingerprint existed at or before the recorded blockchain time.

The recorded time is a reference point, not the moment the document was created.

How to verify a claim document against a timestamped fingerprint

This procedure assumes someone fingerprinted the document earlier and kept the certificate.

1- Preserve the file exactly as received. Do not open and re-save it, convert it, print it to PDF, compress an image or rename it through software that rewrites it. Any re-save can change the bytes and produce a different hash even when the visible content looks identical.

2- Obtain the proof references. You need the certificate, plus the original file, the SHA-256 hash or the certificate ID.

3- Calculate the SHA-256 hash of the file. On Certelo’s verification page, the hash is generated locally in your browser and checked against the blockchain, and the file is not sent to Certelo.

4- Compare the results. If the calculated hash matches the registered one, the file is identical to the version that was recorded. If it does not match, the file is a different version. The check does not say why it differs.

5- Read the recorded time. Note the blockchain timestamp and treat it as “existed at or before this time.”

6- Write down the check. Record who ran it, when, which file name and size you tested, the hash you calculated and where the file came from.

Where this fits in a claims workflow

The following uses are analysis, not documented Certelo customer practice.

On the insurer side:

Fingerprinting files at intake creates a reference point for the stage after receipt. If a dispute later arises over whether a submitted estimate or photo was altered during handling, the insurer can compare the current file with the intake fingerprint. This protects the insurer’s own record, and it also protects the claimant against an allegation that a file was changed internally.

On the policyholder or contractor side:

Fingerprinting inventories, pre-loss photographs, estimates and invoices before submission creates a dated reference for those exact files. It supports the position that the version submitted is the version that existed earlier. It does not show that the photographs depict real, undisturbed conditions.

For third-party documents:

A repair shop or medical provider could fingerprint what it issues. The reviewer then has a reference that does not depend on the claimant’s copy.

A hypothetical example

This example is invented for illustration. A policyholder fingerprints a contractor’s repair estimate on the day it is received. Weeks later the insurer receives an estimate with a higher total. Hashing the submitted file produces a different value from the recorded one, so the two files are not identical. This does not show who changed the figure or whether the change was deliberate; it tells the reviewer to ask for the original and investigate the difference.

What hash verification cannot tell you

Pair hash checks with other controls, because they have clear limits.

Truthfulness. A fabricated invoice can be fingerprinted like a genuine one. A matching hash shows consistency over time, not honesty.

Authorship and identity. Certelo’s compliance page states that it does not prove authorship and does not verify the identity of the person who submitted a file. Because no registration is required, the on-chain record contains the hash and timestamp only.

Real-world accuracy. A timestamped photo may be a manipulated or AI-generated image. Image analysis and source checks address that risk.

Changes before fingerprinting. If a file was edited before it was hashed, the hash faithfully records the edited version.

Context and custody. A reviewer must still assess who held the file, how it moved and whether the surrounding records are consistent.

Certelo’s compliance page suggests keeping supporting records alongside the certificate, such as payment receipts, internal communications and system logs, to help connect the file to the person who submitted it.

A short verification record checklist

> The exact original file, unchanged

> The Certelo certificate PDF

> The SHA-256 hash and the certificate ID

> The date, time and method of your own verification

> Records showing where the file came from and who handled it

> Results of any separate forensic or image analysis

Next step

If you already hold a Certelo certificate, you can check a claim document on Certelo’s verification page using the file, its SHA-256 hash or the certificate ID. For legal questions about using a record in a specific claim or proceeding, consult a qualified professional. This article is general information, not legal advice.