About Captilo
Privacy-first blockchain certificate verification platform
What is Captilo?
Captilo is a privacy-first verification platform that validates PDF certificates against the Constellation Network blockchain. We provide a simple, secure way to verify the authenticity of digital certificates without storing any user data.
Built with security and privacy at its core, Captilo ensures that all verification processes happen server-side, preventing any possibility of tampering while maintaining complete user anonymity.
How Verification Works
1. Upload PDF Certificate
You upload a Captilo PDF certificate to our secure server. The file is temporarily stored for processing only.
2. Image Hash Recalculation
Our server extracts the embedded image from the PDF and recalculates the SHA-256 hash from the actual pixel data. This prevents image-swapping attacks where someone could replace the photo but keep the original hash text.
3. Compound Fingerprint Calculation
The system builds a compound fingerprint by combining the image hash with metadata (timestamp, location, device info) and calculating a SHA-256 hash of the canonicalized JSON.
4. Blockchain Verification
The compound fingerprint is queried against the Constellation Network blockchain. If found, the certificate is verified as authentic and its submission details are returned.
5. Immediate Deletion
After verification, the PDF is immediately deleted from our server. Nothing is stored, ensuring complete privacy.
Why Blockchain Verification?
Immutable Proof
Once a certificate is submitted to the Constellation Network blockchain, it cannot be altered or deleted. This creates an immutable record of authenticity.
Tamper-Proof
Blockchain technology ensures that any attempt to modify a certificate would change its fingerprint, making tampering immediately detectable.
Decentralized Trust
Verification doesn't rely on a central authority. The blockchain network itself provides cryptographic proof of authenticity.
The Captilo Mobile App
The Captilo mobile app captures forensic-grade photos with tamper-proof metadata. When a photo is captured with Captilo:
The image is hashed using SHA-256- Metadata (location, timestamp, device info) is captured
- A compound fingerprint is generated and submitted to the blockchain
- A PDF certificate is generated with the proof details
This website verifies Captilo certificates by recalculating the fingerprint and checking it against the blockchain submission.
Security Features
Server-Side Processing
All extraction and hash calculation happens on our server, preventing client-side manipulation.
Image Hash Recalculation
We extract and rehash images from pixel data to prevent image-swapping attacks.
No Data Storage
PDFs are deleted immediately after verification. We never store your certificates.
Anonymous Verification
No user accounts required. Verify certificates completely anonymously.