Blockchain-based digital proof

Full-stack proof of concept around traceability and digital evidence (kept intentionally high-level for client confidentiality).

At the center of the project is the ability to make a technically sound evidence chain understandable in the interface: connecting signals, media, hashes, anchoring, and verification in a workflow usable by human operators. Business and client context is kept intentionally high-level (confidentiality).

Overview

Context

B2B project in a setting that required strong digital traceability and evidence practices. Client names, sectors, and detailed use cases are not disclosed (confidentiality).

Timeline

2025-2026

Stack

Docker · Python · React · TensorFlow

Published

March 2024

My role

Full-Stack Engineer

I built the main React/Django application, structured the integrity-verification workflow, secured access to media evidence, and integrated an existing blockchain/API building block as a technical validation layer inside a usable evidence workflow.

Key responsibilities

Designed and built the React/TypeScript interface for browsing records, media, and proof data
Developed the Django backend as a secure access layer for records, media assets, and anchor information
Integrated and adapted an existing blockchain/API building block used as a validation layer
Implemented the integrity-verification workflow linking records, media evidence, and anchor data
Structured the self-hosted deployment stack with Docker, Nginx, PostgreSQL, and operations documentation
Worked on making traceability and digital proof understandable for operational users

Proof points

Evidence chain

Signals, hash, anchoring, verification, and operator review

Media security

Backend-side ZIP extraction and temporary signed URLs

Architecture

Main React/Django app plus blockchain/API validation layer

Team setup

Main application designed and developed on the React/Django side
Existing blockchain/API building block studied, integrated, and adapted to the project need
Work focused on technical validation and operational usability

The problem to solve

When digital evidence must stand up to scrutiny, raw data alone is not operationally useful. It must be linked to media evidence, protected against tampering, technically verifiable, and presented in a workflow that supports traceability or evidentiary use.

The goal was to validate an end-to-end chain from event capture to integrity verification in a format that remains meaningful both technically and operationally.

How I structured the solution

I built the system around two complementary layers: a main React/Django/PostgreSQL application for consultation and verification, and a blockchain/API building block used during development to materialize anchoring and proof logic.

The validated workflow links event records, metadata, media evidence, hashing, anchor retrieval, and integrity comparison inside a single interface.

The goal was not to build an overly complex blockchain product, but to demonstrate that secure digital evidence can be technically validated and then presented in a way that remains understandable for human review.

Screenshots

Challenges that shaped the project

Turning raw data into readable evidence

Problem

Coordinates, timestamps, transactions, and ZIP archives are difficult to use operationally until they are organized into a coherent review workflow.

Solution

I designed a unified interface that clearly separates media, blockchain proof, and raw-data views while surfacing the metadata most useful for operational review.

Making blockchain a useful trust signal

Problem

A hash or transaction has no product value if users cannot understand what it proves in practice.

Solution

I added a dedicated verification screen, made the expected-versus-anchor comparison explicit, and translated technical verification into readable status signals.

Securing access to sensitive media evidence

Problem

Media evidence cannot be exposed through simple static links in a system that aims to be taken seriously from a security standpoint.

Solution

I implemented backend-side retrieval and extraction, temporary signed URLs, and temporary-file lifecycle handling to secure access to evidence assets.

Results and impact

Validated the feasibility of a strongly traceable evidence chain for field-originated records
Demonstrated a readable workflow linking signals, media, technical proof, and integrity verification
Provided a credible security model for controlled access to media evidence
Turned a complex cryptographic topic into a workflow usable for human review
Successfully integrated an existing blockchain/API layer into an application built for real operational usage

Visible proof

The project is positioned as a functional proof of concept, but it already relies on concrete proof: real screenshots, an explicit integrity workflow, and visible security mechanisms inside the interface.

Real screenshots of login, filters, blockchain proof, and review screens
Integrity verification based on hash comparison and anchor-proof retrieval
Temporary signed URLs for secure media access
Containerized architecture with main app and blockchain/API validation layer