SSH: Definition, Functions, Advantages, Types, and Advantages

What is SSH? SSH is an essential network protocol for securing data communication on remote devices. The security system in SSH is equipped with strong encryption and secure authentication processes. SSH can perform several functions such as remote login and file transfer with a high level of security.

SSH Meaning

What is SSH? SSH stands for Secure Shell. SSH is a network protocol used to secure communication between remote devices over an unsecured connection. SSH is a solution that provides strong end-to-end encryption, secure authentication, and encrypted data transmission and reception. This protocol is used to access, control, and transfer data securely between devices connected within a network.

In its implementation, computers and modems have only limited capabilities to connect to the remote internet, such as collecting sensor data and controlling specific systems. Remote computers running standard operating systems such as Linux or Windows allow users to access software on those computers. In addition to accessing them, users can also repair or update software and configuration data as needed. This maintenance action requires system administrators to open a connection to the shell program (command prompt) running on the remote computer, which uses the Secure Shell (SSH) protocol. SSH is a replacement technology for the insecure Telnet Protocol and Unix Remote Shell Protocol.

Functions of SSH

The primary function of SSH is to provide secure network communication between connected devices. Below are some key functions of SSH:

Secure Communication

One of SSH’s main functions is securing network communication. This protocol uses end-to-end encryption to protect data transmitted over the network from monitoring, interception, or manipulation by unauthorized parties. This ensures the confidentiality, integrity, and authenticity of the data sent via the SSH connection.

Remote Login

SSH allows users to perform remote login to distant devices securely. By using an SSH client, users can log into these devices and gain access to the shell or command-line interface to execute commands and manage the device.

Secure File Transfer

SSH can also be used to transfer files securely between remote devices. Using SCP (Secure Copy Protocol) or SFTP (SSH File Transfer Protocol), users can send and receive files with end-to-end encryption.

Port Forwarding

SSH supports port forwarding, which allows users to forward network traffic through a secure SSH connection. This feature is useful for securing access to services running on remote devices or accessing services on a local network through a secure SSH connection.

Tunneling

SSH tunneling is a technique for securing and managing remote connections over the internet. In this context, system administrators use the Secure Shell (SSH) protocol to access remote computers that do not support incoming connections. They utilize a proxy host or jump host as an intermediary. Users open an SSH tunnel from their controlling computer to the jump host, forming a virtual network. Through this tunnel, the controller can establish an SSH connection to the remote computer. SSH key certification and X.509 certificates are stored in GitHub for authentication. This setup enables efficient and secure management of multiple remote computers without requiring direct connections from the internet.

Advantages and Disadvantages of SSH

Below are some advantages and disadvantages of the SSH protocol:

Advantages of SSH

High Security – SSH uses end-to-end encryption to protect data sent through the connection. This encryption makes it difficult for unauthorized parties to monitor, steal, or manipulate data transmitted over the network.
Secure Authentication – SSH provides secure authentication mechanisms to identify and verify users connecting to remote devices. Authentication involves using public and private keys, passwords, or digital certificates.
Flexibility – SSH can be used for various purposes, including remote login, file transfer, port forwarding, and tunneling. This allows users to securely access, manage, and transfer data between connected devices.

Also Read : What is UDP

Disadvantages of SSH

Complex Initial Configuration – Setting up SSH initially requires proper configuration, including public and private key setup, authentication settings, and other security configurations.
Vulnerability to Brute Force Attacks – SSH can be vulnerable to brute force attacks where attackers attempt multiple password combinations to gain unauthorized access.
Requires a Stable Internet Connection – SSH requires a stable internet connection to function. If the internet connection is disrupted or unstable, it can result in difficulties accessing remote devices via SSH.

Types of SSH

Below are some commonly used types of SSH:

OpenSSH

OpenSSH is the most popular and widely used SSH implementation. It is an open-source project available for free and can run on various operating systems, including Linux, macOS, and Windows.

Dropbear

Dropbear is a lightweight SSH implementation suitable for devices with limited resources, such as routers, embedded devices, and lightweight Linux-based operating systems. Dropbear provides a subset of SSH features, including remote login and file transfer.

PuTTY

PuTTY is a popular graphical SSH client for the Windows platform. It provides an intuitive user interface and supports features such as remote login, file transfer, and port forwarding.

Tectia SSH

Tectia SSH is a commercial SSH solution developed by SSH Communications Security. It offers strong security and management features, as well as additional tools such as SFTP and security monitoring.

SecureCRT

SecureCRT is a popular SSH and Telnet client application for the Windows platform. Besides SSH features, SecureCRT also provides additional functionalities such as backup and recovery, credential manager integration, and automated scripting.

It should be noted that many other SSH implementations and clients are available beyond this list. The best choice depends on user needs and preferences.

Also Read : What is RDBMS

Understanding SSH WebSocket

SSH WebSocket is a technology that integrates Secure Shell (SSH) with WebSocket to enhance internet connection speed and security. WebSocket is a communication protocol that allows real-time data transfer through a single TCP connection that remains open. With this combination, SSH can work more efficiently and stably, especially in networks that restrict access to standard SSH port.

How SSH WebSocket Works

Connecting to the WebSocket Server – The client initiates a connection to the server using the WebSocket protocol via standard HTTP/HTTPS ports (80 or 443).
Establishing an SSH Tunnel over WebSocket – Once the WebSocket connection is successfully established, the SSH session is forwarded through this path, allowing the server to encrypt and secure data traffic.
Stable Data Transfer – Data from the SSH session is packaged into WebSocket packets and transmitted in real time, resulting in a faster, more responsive, and stable connection than conventional SSH.

Advantages of SSH WebSocket

Bypassing ISP Blocking – WebSocket operates through standard HTTP/HTTPS ports (80 or 443), allowing SSH connections to avoid firewalls or ISP restrictions that block standard SSH port (22).
Optimized Connection Speed – With a tunneling system, WebSocket usage reduces latency and increases data communication efficiency.
Data Security – SSH WebSocket employs high-level encryption to protect data from cyber threats.
Compatibility with Various Networks – SSH WebSocket can be used in networks with strict restrictions, such as offices, campuses, or public networks that limit direct SSH access.

SSH WebSocket is a modern and efficient solution for users who want to increase the speed and security of SSH connections , especially in networks that restrict direct SSH access. With this method, users can enjoy a more stable, fast, and secure connection without having to worry about restrictions from their internet service provider (ISP) .

Conclusion

SSH is a network protocol that is crucial in securing remote data communications through strong encryption and secure authentication. In addition to being used for system administration and encrypted file transfers, SSH is a leading solution that also supports additional security features such as port forwarding and tunneling. While it has challenges such as complex initial configuration and the risk of brute force attacks, its advantages in protecting against cyber threats make it a top choice compared to legacy protocols such as Telnet.

Innovations such as SSH WebSocket further enhance the efficiency and stability of connections, making it an essential solution for network administrators and users who prioritize digital security. Learn essential technology skills by joining the SSH program at the Best Private University in Indonesia ! Advance your career and become an expert in network security today!

References

T. Ylonen; C. Lonvick (January 2006). The Secure Shell (SSH) Protocol Architecture. IETF Trust. doi:10.17487/RFC4251. RFC 4251

Toledo, S. (2023). SSH tunneling to connect to remote computers. Software Impacts, 17(September), 100545. https://www.sciencedirect.com/science/article/pii/S2665963823000829