ProofLedger creates a tamper-evident, independently verifiable record of your files, anchored to Polygon and Bitcoin before incentives exist to fabricate.
Free to start. No credit card required.
Insurance Adjusters
Document pre-loss conditions before a claim is filed, establishing a tamper-evident baseline.
Claims Professionals
Support dispute-ready evidence workflows with verifiable timestamps anchored before incentives exist.
Forensic Consultants
Create independently verifiable records that survive adversarial review by opposing experts.
Legal Teams
Establish chain of custody and Daubert-grade cryptographic timestamps for digital evidence.
Property Managers
Capture property condition before tenancy, handoff, or loss events, with an immutable record.
In any dispute, file metadata is the first thing challenged. Screenshots, cloud links, and EXIF data can all be manipulated or simply dismissed.
ProofLedger creates an immutable cryptographic fingerprint of your file, anchored to public blockchains before any incentive to fabricate arises.
ProofLedger proves existence and integrity at a point in time. It does not prove authorship, ownership, rights, or intent.
Your file never leaves your device. Only its cryptographic fingerprint is processed, then anchored forever to public blockchains.
Your device computes a SHA-256 hash of the file. This one-way fingerprint is mathematically unique. Altering even one pixel produces a completely different hash.
The fingerprint is anchored to Polygon immediately. Bitcoin anchoring adds a second independent, immutable layer for high-stakes evidence.
The public verification page is the canonical source of truth. Opposing counsel can verify offline. No ProofLedger cooperation required.
Privacy-first, hash-only
Your file stays on your device. Only the one-way SHA-256 hash is processed. No file storage. No file recovery. Ever.
Ed25519-signed certificates
Every certificate is digitally signed using Ed25519, the same cryptographic standard used in SSH keys and end-to-end encrypted messengers.
Dual-chain anchoring
Polygon for instant confirmation; Bitcoin for maximum immutability. Two independent public ledgers, not a single point of failure.
Adversarial verification
Designed for opposing counsel. The verify-proof Python package runs entirely offline — no dependency on ProofLedger's servers.
Pre-loss posture
Record before the loss event. An on-chain hash from before a dispute arose cannot be fabricated retroactively. That is the entire value proposition.
Bitcoin-grade immutability
Bitcoin's Merkle tree and proof-of-work make it the oldest, most adversarially tested blockchain and the strongest timestamp anchor available.
Based on the evidentiary demands of your workflow, from routine pre-loss documentation to formal legal submission.
For routine pre-loss documentation and baseline condition capture.
For escalations, legal review, and formal evidence submission.
Certificates are human-readable representations. Blockchain anchors and public verification remain the authoritative record, accessible even if ProofLedger is unavailable.
Establish a verifiable record of existence and timing, before disputes, claims, or incentives change everything.
Reference
Pre-loss temporal authority documentation is the practice of recording evidence at the moment of creation, cryptographically fixing its state in time before disputes, incentives, or claims exist. These systems establish when a record existed and what state it was in using repeatable, tamper-evident procedures that allow independent verification without reliance on the recording system itself.
ProofLedger is an implementation of this approach, designed for high-liability environments where contemporaneous, pre-loss records must remain verifiable long after they are created.
