What is SSH? Complete explanation!

SSH stands for Secure Shell, also called “shell”. It is a tool to log in to another computer or server in an encrypted manner to remotely execute commands on these other computers or servers. This is done through a shell. This process is very safe, because the data that is sent over the connection is encrypted and therefore impossible for outsiders to get commands or passwords from.

Long story short: malicious persons work by tapping the internet connection. This is not possible if SSH is used, because the connection is encrypted. SSH is thus a network protocol that allows cryptographic encryption to securely exchange data and establish communication between two computers or servers.

How does SSH work?

Public-key cryptography is used to encrypt the data using SSH. This means that when a connection is made, the data is encrypted by symmetric cryptography. Only the systems connected via this connection know the key of the encryption. When unauthorized people log into the network, the encryption will deny these people. This makes it impossible to see and steal data, such as important passwords.

How do you use SSH?

SSH is a useful tool when you work with insecure connections. However, to use this program, you must first download an SSH client via Windows. Once installed, you can create a password or SSH key to login. You can then contact other systems, such as the server, another computer or the web host. It is important that your web host supports SSH. At Hypernode we support this of course. Encryption can also occur at the domain level, which may be applicable when there are multiple users accessing the domain. In this case, data can be protected from other users.

SSH is used on a command basis, which ensures that users with little or no programming experience can get started with the program. However, there are several, very clear manuals to be found on the internet for support. Examples of SSH commands:

• traceroute IP address: Run traceroute
• history: shows which commands you have already executed
• shutdown -r now: restart the server
• free –m: shows how much memory is still free
• pwd: show which folder you are in
• rm FILE: delete file or folder

Why use SSH?

Of course, SSH offers a lot of security for data distribution and communication between different computers, which is a big advantage. In addition, a major advantage of SSH is that authentication with a public and secret key pair is possible. This allows SSH applications to be used automatically without the need for a password. In addition, any system to which the public key has been assigned can be logged on by using the secret key. If the owner decides to change the password of the secret key, there will be no consequences for the key pair. SSH replaces older protocols, such as telnet, which did not yet use encryption. SSH is therefore a lot more secure.

Different SSH systems

Of course there are also different variants within SSH that you can join and use. Three of these will be briefly explained.

1.PuTTY

The most famous Secure Shell client is PuTTY, which is a protocol that is available for free and can be installed on Windows. Connecting to a remote SSH server is as simple as typing in the IP address or domain and then opening it. You may be asked for your username and password to connect to the remote SSH server. This can be replaced by connecting with PuTTY’s SSH keys without using passwords. It is also possible to create a shortcut to PuTTY to open the SSH session with one click of your mouse.

2.KiTTY

A good alternative to PuTTY, which is also free and open source , is KiTTY. This program is designed to function as a Windows SSH client. It contains all the functions that PuTTY also has with some extra functions added. The main additional features are:

• Automatically remember password
• KiTTY is a light SSH client and requires relatively few resources from the computer or server on which it is installed.
• An icon for each session. This makes it a well-arranged program.
• Run a local, saved script on a remote session.
• pscp.exe and WinSCP integration. Here, pscp is a command-line application and WinSCP (Windows Secure CoPy) is an open-source graphical Windows application that uses SSH.
• Sessions are filtered.
• Shortcut for commands that are predefined.
• Quick start of a double session.
• Send to boxes. With this, open sessions can be placed in a course and an overview can be made.

3.MobaXterm

PuTTY is a good free SSH client and the most common among Windows users. However, there are also flaws in this client, one of the missing features is to open a session in tabs. Alternatives to PuTTY (and similar clients, such as KiTTY) are available with these missing features added. These alternatives also combine other protocols such as FTP, SFTP and more within one tool. This can be useful for home server users or for a server administrator.

An example of an alternative to PuTTY is  MobaXterm. This program is free to download, but there is also a paid Pro version available. This protocol is a single Windows application that offers many functions for IT administrators, programmers, webmasters and other people who want to manage a system remotely. Some important features of MobaXterm are:

• Supports various protocols such as SSH, X11, RDP, VNC, FTP, MOSH and many more.
• Brings Unix commands to Windows, such as bash, cat, grep, sed, awk and many more.
• Requires relatively few resources from the computer or server on which the client is installed.
• Embedded X Server and X11 forwarding. Communication agreements are recorded by the X server and the X11 forwarding is a mechanism that allows the user to launch remote applications, but where the password screen is forwarded to the local Windows computer.
• GUI (graphical user interface) file, which allows the use of graphics, widgets, and text.
• Possibility to expand with plugins.
• Tabs available for SSH.

MobaXterm does not contain intrusive ads to upgrade to the Pro version or to the free Home edition which can be pleasant for the user. However, the paid version offers more features.

Conclusion

Whether you use PuTTY, KiTTY, MobaXterm or another SSH client, all systems ensure that your data is secure via SSH keys and can be communicated over distance through advanced encryption, making your data safe.