Drop any file to recompute its fingerprint, or enter a Proof ID to look it up on-chain. No account required.
No trust in ProofLedger required. Every step is reproducible by anyone, on any device.
Your browser computes the SHA-256 hash of the file locally. The same file always produces the same fingerprint. Any alteration — even a single bit — produces a completely different hash.
The computed hash is compared to the fingerprint anchored on Polygon and/or Bitcoin at the moment of recording. A match proves the file is byte-for-byte identical to the original.
The Ed25519 platform signature on the certificate is checked against ProofLedger's published public key. This confirms the certificate was issued by the platform and has not been modified.
The open-source verify-proof Python package lets anyone reproduce the full verification process offline — using only the certificate JSON and a direct connection to the public blockchain. No dependency on ProofLedger infrastructure, ever. Designed so opposing counsel can verify independently.
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.
