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README.md

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-TRIZ SECURITY COMMON
+# TrizTech Security JWT Library
+
+![Java](https://img.shields.io/badge/Java-8%2B-blue) ![JWT](https://img.shields.io/badge/JWT-RS256-green) ![JJWT](https://img.shields.io/badge/JJWT-0.12.x-orange) ![Version](https://img.shields.io/badge/version-1.0.0-success)
+
+Internal Java library dedicated to the **generation** and **validation** of **JWT** tokens signed with **RSA (RS256)**, intended to be shared across applications within the **TrizTech** ecosystem.
+
+---
+
+## 1. Overview
+
+`TrizTech Security JWT Library` is a utility Java library that allows you to:
+
+- **generate** JWT tokens signed with **RS256**
+- **validate** JWT tokens using an **RSA public key**
+- **load** RSA keys from **PEM** format
+
+---
+
+## 2. Use Cases in the TrizTech Ecosystem
+
+### Related Applications
+
+- **auth-triz** — holds the **RSA private key** and generates JWT tokens
+- **trizstock** — holds the **RSA public key** and validates tokens
+- **trizdistribution** — holds the **RSA public key** and validates tokens
+
+> This approach ensures that **only auth-triz can sign** tokens. The other applications can only verify them.
+
+---
+
+## 3. Features
+
+- JWT generation signed with **RSA / RS256**
+- JWT validation using an **RSA public key**
+- Loading **private** and **public** RSA keys from PEM files
+- Support for **custom claims**
+- Simple API with `static` methods
+- Compatible with **Java EE / Spring (non-Spring Boot)**
+
+---
+
+## 4. Project Structure
+
+| Class | Role |
+|--------|------|
+| `JwtUtils` | JWT token generation and validation |
+| `KeyLoader` | RSA key loading from PEM files |
+
+---
+
+## 5. Requirements
+
+- Java 8+ (recommended: Java 17)
+- JJWT 0.12.x
+- Valid RSA keys in PEM format
+
+---
+
+## 6. Generate RSA Key Pair with OpenSSL
+
+### 1) Generate the private key
+Run this command in Terminal / Git Bash / PowerShell:
+
+```bash
+openssl genpkey -algorithm RSA -out private_key.pem -pkeyopt rsa_keygen_bits:2048
+```
+
+This creates:
+
+* private_key.pem
+
+Example format:
+```xml
+-----BEGIN PRIVATE KEY-----
+MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBK...
+-----END PRIVATE KEY----- 
+```
+This is exactly the format your **KeyLoader.loadPrivateKey(...)** expects:
+
+* header: -----BEGIN PRIVATE KEY-----
+
+### 2) Generate the public key from the private key
+
+```xml
+openssl rsa -pubout -in private_key.pem -out public_key.pem
+```
+
+This creates:
+
+* public_key.pem
+
+Example format:
+
+```xml
+-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgK...
+-----END PUBLIC KEY-----
+```
+
+This is exactly the format your **KeyLoader.loadPublicKey(...)** expects:
+
+* header: -----BEGIN PUBLIC KEY-----
+
+---
+
+## 7. Auteur
+Developed for the **TrizTech ecosystem** — to centralize and share JWT logic between `auth-triz`, `trizstock`, and `trizdistribution`.