What Is Secure Shell (SSH)?

Secure Shell (SSH) is a secure protocol for accessing and managing remote systems over a network. For businesses, it’s commonly used to connect to cloud servers, run remote commands, or transfer files securely.

What sets SSH apart is encryption. It protects every session, login, and command from being intercepted. That’s why it’s widely used for server administration, automation scripts, and secure file transfers in business environments.

If your team needs reliable access to critical infrastructure or wants to avoid exposing credentials, SSH is a go-to tool for secure remote operations.

How Does Secure Shell Work?

Secure Shell (SSH) works by creating an encrypted connection between a client and a remote server. This secure tunnel ensures that any data, commands, or credentials shared during the session can’t be intercepted or tampered with.

When a user initiates an SSH session, the client verifies the server’s identity using a cryptographic key. Once verified, the user logs in with either a password or an SSH key. All communication after that is encrypted end-to-end.

SSH runs over TCP (typically on port 22) and supports secure command execution, file transfers (via SCP or SFTP), and port forwarding. These are useful for remote system administration and secure infrastructure access in a business environment.

Key Features of SSH

Understanding SSH’s key features gives clarity on how it strengthens remote access and system security. These features are what make SSH a preferred choice in business IT environments:

• End-to-End Encryption: All communication between client and server is encrypted, preventing data interception or tampering.
• Authentication Options: SSH supports password-based login as well as public-private key authentication for stronger, credential-less access.
• Remote Command Execution: Users can securely execute shell commands on remote servers, which is ideal for remote administration and automation.
• Secure File Transfers: SSH enables encrypted file transfers through SCP (Secure Copy Protocol) or SFTP (Secure File Transfer Protocol).
• Port Forwarding (Tunneling): SSH can securely tunnel other protocols, such as HTTP or database traffic, which is useful for protecting sensitive connections.
• Session Integrity: SSH protects against session hijacking, DNS spoofing, and MITM attacks, provided host key verification is correctly performed.

Common Use Cases of SSH

If you're implementing SSH for your business, it's important to realize how and where it's often used. This will help you determine whether SSH is the right solution.

• Remote Server Management: IT teams use SSH to securely access servers across data centers or cloud platforms, perform updates, and manage services.
• Automated Backups and Scripts: Scheduled tasks and scripts often rely on SSH to execute commands or sync data between remote systems without human input.
• Secure File Transfers: Businesses use SFTP over SSH to exchange files between internal systems or with external partners without exposing them to public networks.
• Port Forwarding for Internal Tools: SSH tunnels allow secure access to internal dashboards, development tools, or databases from remote locations.
• Version Control in DevOps: Development teams authenticate Git access using SSH keys to securely push or pull code from repositories like GitHub or GitLab.
• IoT Device Access: In industries with smart devices or remote sensors, SSH is often used for secure access, monitoring, and updates.

SSH vs Telnet: What’s the Difference?

Before SSH, many businesses relied on Telnet, a protocol that transmits data in plain text. This created serious security gaps, especially in enterprise settings.

SSH closed those gaps by encrypting communication and offering stronger authentication methods. It quickly became the industry standard for secure system administration, file transfer, and automated remote tasks.

If you’re still comparing SSH and Telnet, here’s a quick breakdown of how they differ:

What Is SSH Tunneling?

SSH tunneling is a method of securely forwarding network traffic from one system to another using the encrypted SSH protocol.

It allows businesses to create secure pathways (or “tunnels”) for data to travel over untrusted networks. This is especially useful for accessing internal applications, databases, or systems from remote locations without exposing them to the internet.

SSH tunnels can forward local, remote, or dynamic ports. Thus, you can route traffic securely from a local device to a remote server or even set up a temporary encrypted proxy.

SSH vs SSL/TLS: Key Differences

Now that you've seen how SSH tunneling works, it's common to question how it compares to SSL/TLS. Both are encryption protocols that protect data, but they’re not built for the same purpose.

If you’re setting up secure remote access or encrypted data transfers, understanding the difference helps you choose the right solution. Here’s a quick breakdown of when SSH makes more sense and where SSL/TLS fits better.

SSH Key Management

SSH keys have been mentioned several times, but what exactly are they? SSH keys are cryptographic credentials used to authenticate access between a client and a server. They come as a pair, a private key kept securely on the user’s device and a public key stored on the target system. When the two match during a connection attempt, access is granted without the need for passwords.

Managing these keys involves securely generating, storing, distributing, and revoking them. For businesses, this means controlling who has access, where keys are used, and ensuring they don’t linger beyond their intended purpose. Without proper management, organizations risk unauthorized access and policy violations. That’s why many implement automated key rotation, expiry policies, and central visibility tools.

UTunnel’s Take on Secure Shell (SSH)

For businesses looking to simplify and secure SSH access, UTunnel offers a browser-based solution through OneClick Application Access. It enables authorized users to initiate SSH sessions with a single click — no local client software or manual key setup required.

OneClick SSH Access for Secure and Controlled Connectivity

The OneClick Application streamlines SSH access for teams and contractors by eliminating traditional CLI configurations and shifting session management to the browser. This makes it easier to grant access without compromising on control or security.

Connections are governed by UTunnel’s Zero Trust Application Access (ZTAA) framework. Access is policy-driven and based on user identity, device, location, and time. This reduces lateral movement risk and ensures each session aligns with your organization’s security requirements.

It also supports rotating devices, enforces role-based permissions, and minimizes setup overhead. Everything’s handled while being compliance-ready, with clientless SSH access.

FAQs on SSH

Is Secure Shell UDP or TCP?

SSH uses the TCP protocol. It relies on a reliable, connection-oriented communication channel to maintain secure sessions.

What port does SSH use?

By default, SSH runs on port 22. However, it can be configured to use a different port based on your setup or security preferences.

What is the difference between a VPN and a Secure Shell?

A VPN encrypts all network traffic between devices, creating a secure tunnel across the internet. SSH, on the other hand, is primarily used to securely access remote systems and transfer files at the command level.

Is SSH better than VPN for remote access?

It depends on the use case. SSH is ideal for server management and secure file access. VPNs are better for full network access or applications that need a broader range of connectivity.

How are SSH keys more secure than passwords?

SSH keys are cryptographic credentials that are nearly impossible to brute-force. Unlike passwords, they aren't transmitted over the network and can't be reused across services.

Can I transfer files using SSH?

Yes, SSH supports secure file transfer via tools like SCP (Secure Copy) or SFTP (SSH File Transfer Protocol).