SSH or Secure Shell is a powerful and versatile tool that enables secure communication between two remote systems. With the advent of technology, controlling devices remotely across vast distances has become a reality.
One such technology is SSH, or Secure Shell, which allows for secure connections to remote servers and internet-enabled devices. But what exactly is SSH, and how does it ensure the security of your connection?
This article delves into the inner workings of SSH, providing a detailed understanding of its functionality and security measures.
SSH: Understanding its Functionality and Security Measure
SSH, or Secure Shell, is a protocol for remotely managing servers and accessing their settings and files. It is an improvement on Telnet, which was previously used but deemed insecure due to the lack of encryption.
It uses a combination of encryption methods such as symmetric, asymmetric and hashing to secure the connection. This makes it known as a Secure Shell connection.
With SSH, the remote user can be authenticated before the connection is established, and it allows for input and output communication between the client and the server.
It can be used on various operating systems such as OSX, Windows, and Linux, with popular SSH application PuTTY being a common choice for Windows users.
This makes it possible to manage servers without the need for physical access. Additionally, it can be used to manage and access other devices on the same network.
Understanding the benefits of SSH is crucial after learning about its functionality.
Advantages of SSH
SSH will provide you with numerous benefits. What are the benefits? Let’s take a look at the review below.
1. Hosting That is Completely Under Your Control
SSH enables remote control of hosting servers, providing the ability to access and manage them as if you were physically present.
It enables you to monitor server logs, install and uninstall applications, transfer data, and perform a variety of other tasks without physically accessing the server.
This gives you complete control over your hosting and the flexibility to manage it remotely.
2. Prevent Cybercrime
SSH employs several advanced cryptographic techniques to provide robust security.
It can detect and automatically disconnect from connections that are potentially compromised by hackers, protecting against various cyber threats such as IP and DNS spoofing, data manipulation, and unauthorized tracking.
This makes SSH an essential tool for ensuring the security of remote connections.
3. Strict Security Using an Authentication System
If you use SSH, hackers will have a more difficult time stealing your data. Hackers cannot simply steal passwords and user information because it supports data encryption.
How SSH Works?
The SSH protocol operates using a client-server model, in which the SSH client establishes a connection with the SSH server. The client uses cryptographic keys to verify and identify the server, and the connection will only be established if the key used by the client matches the one used by the server.
Once the connection is established, it is secured using symmetric encryption and hashing algorithms to ensure the confidentiality and integrity of data exchanged.
The process begins with the SSH client initiating the connection by contacting the SSH server through the SSH client application (such as PuTTY on Windows).
The server then sends its public key to the client, which responds by providing its key pair. They then verify the connection and establish a secure connection. After that, the client can access the server and exchange encrypted data.
What is an SSH Client?
The SSH client is a program that allows the operating system to connect to an SSH server. For example, Linux and MacOS have this feature built-in, while Windows users can use a program such as PuTTY.
MacOS and Linux users do not need to install any additional applications as the SSH client feature is already built-in in their respective Terminal, to connect, simply use the command “$ ssh username@server address,” as shown below:
The SSH command above establishes an encrypted connection with the ‘username’ user to the server with the IP address ‘31.22.72.55’ or the domain address of the SSH server.
You will be prompted to enter the user’s password, and if the correct one is entered, the connection will be established and you can control the SSH server via the Terminal.
3 SSH Encryption Methods
In the previous section, we briefly touched on the various encryption technologies used in SSH, including symmetric, asymmetric, and hashing.
These three methods work in concert to ensure secure data exchange between the client and server.
1. Symmetric Encryption
Symmetric encryption, also known as shared key encryption, uses a single key to encrypt and decrypt data exchanged between the client and server. This key is typically kept on the server side for identifying trusted users and is shared among all clients.
As long as the connection between the client and server is established, symmetric encryption will function securely. The Key Exchange Algorithm is used to create symmetric encryption and ensures that keys are not exchanged during the data exchange process, making it a secure method.
Additionally, encryption and decryption processes are performed separately on each device, making it impossible for unauthorized third parties to intercept and read the exchanged data.
2. Asymmetric Encryption
Asymmetric encryption is different from symmetric encryption in that it uses two keys, a private key and a public key. The private key is typically only held by the server, while the public key is accessible to the client.
Public keys can be used by any client, but the encryption process can only occur when the public and private keys are paired, not with different keys.
This creates a one-way relationship, meaning that once a message is encrypted, the host (server or client) with the public key will not be able to decrypt it. This is in contrast to symmetric encryption, which uses a single key for both the client and server.
3. Hashing
SSH utilizes a technique called hashing encryption, a type of cryptography that creates a unique, irreversible value called a hash. This one-way hash encryption is used to secure data exchanged during the connection process, it cannot be decrypted.
Hashing is especially useful for validating messages, and SSH uses a system called HMAC (Hash-based Message Authentication Code) to ensure that data cannot be tampered with.
It’s important to note that one-way hash encryption can’t be used in all scenarios, SSH only employs it for message validation and similar purposes.
Summary
Learning about SSH is a crucial step, particularly if you work with client-server connections. While Telnet was previously used, it cannot provide the same level of security as SSH, which uses various encryption technologies to secure data exchanges.
This article aims to provide a comprehensive understanding of what SSH is and how it functions.
If you have any additional questions, please feel free to ask in the comments section and don’t forget to subscribe for updates on technology, digital marketing, and business.
