Technical Architecture
We replace subjective visual inspection with immutable mathematical truth. This document outlines the physical and cryptographic protocols used to secure assets on the Autograph Blockchain.
1. Physical Digitisation (Spectral Topography)
The foundation of our system is the high-fidelity digitisation of the asset. We do not simply take a high-resolution photograph; we capture the physical topography and chemical composition of both the substrate (paper, leather, plastic) and the ink.
| Wavelength Spectrum | Nanometer Range | Primary Detection Utility |
|---|---|---|
| Ultraviolet (UV-C) | 254 nm | Fluorescent bleaching agents in modern paper substrates. |
| Ultraviolet (UV-A) | 365 nm | Iron gall ink degradation and historical paper sizing. |
| Visible (RGB) | 400 - 700 nm | Baseline colorimetry and geometric stroke pathing. |
| Near-Infrared (NIR) | 850 - 940 nm | Pen pressure depth topography and underlying graphite traces (traced forgeries). |
| Short-Wave Infrared (SWIR) | 1200 - 1550 nm | Synthetic vs natural dye differentiation in modern markers (e.g., Sharpie formulations post-1998). |
Data Yield and Pre-processing
A standard scan yields approximately 800MB of raw spectral data. This data is processed through our proprietary tensor pipeline to isolate the specific geometry of the ink deposit relative to the substrate topography. This ensures that minor environmental changes (e.g., humidity affecting paper curl) do not wildly alter the core biometric signature.
2. Cryptographic Hashing (SHA-256)
The processed 3D spectral map is too large to store on-chain efficiently, and public exposure of the raw data could theoretically aid sophisticated forgers. Therefore, we utilize the SHA-256 hashing algorithm.
// The fundamental property of a cryptographic hash:
Input A: Authentic 1927 Babe Ruth Signature Data (800MB)
Output Hash: 5e884898da28047151d0e56f8dc6292773603d0d6aabbdd62a11ef721d1542d8
Input B: Autopen Forgery of 1927 Babe Ruth Signature (Visually identical)
// Even a 1% variance in pen pressure depth completely changes the hash:
Output Hash: 8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92
3. Blockchain Anchoring and Provenance
Once the hash is generated, it is anchored to the Ethereum mainnet via a custom Smart Contract. This creates an immutable, timestamped record that proves the asset existed in that exact physical state at that specific moment.
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Minting the Non-Fungible Token (NFT)
We issue an ERC-721 token to the owner's wallet. Unlike standard NFTs which point to a generic image URL, our token metadata contains the SHA-256 hash of the physical object's spectral topography.
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Chain of Custody
When the physical item is sold, the NFT is transferred. The blockchain ledger permanently records this transfer, creating a public, unbroken chain of custody (provenance) that cannot be forged.
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Re-verification
At any point, a new owner can rescan the asset. If the new hash matches the on-chain hash, authenticity is mathematically proven. If the item was swapped for a forgery, the hashes will fail to align.