SSH (Secure Shell) is a cryptographic network protocol for secure data communication over unsecured networks. It enables encrypted access to remote servers, secure file transfers, and command execution. Below are key concepts and practical guides:

🧠 Core Features

  • Encryption: AES-256 or ChaCha20 algorithms protect data in transit
  • Authentication: Public-key authentication (SSH keys) or password-based methods
  • Port Forwarding: Secure tunneling for local network access
  • SSH Tunneling: Encrypts traffic between client and server

📌 How SSH Works

  1. Key Exchange: Establishes secure session keys using Diffie-Hellman algorithm
  2. Authentication: Verifies user identity through public key or password
  3. Secure Channel: Encrypts all subsequent communications

📦 Common Use Cases

  • Remote server management 🌐
  • Secure file transfer 📁
  • Port forwarding for applications 🔄
  • Secure remote desktop access 🖥️

🛠️ Configuration Examples

# Basic SSH connection
ssh username@remote_server_ip

# Using SSH keys
ssh -i /path/to/private_key username@remote_server_ip

# Port forwarding
ssh -L 8080:localhost:80 username@remote_server_ip

🧪 Security Best Practices

✅ Use strong, unique passwords
✅ Enable two-factor authentication (2FA)
✅ Regularly update SSH keys 🔐
✅ Disable password authentication if possible

📚 Expand Your Knowledge

For deeper insights into network security principles, visit our Network Security Fundamentals tutorial.

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