SSH key: Learn how to configure the tool

SSH key: Learn how to configure the tool

SSH is a type of secure protocol used as a means of remote connection to Linux servers. After connection, commands typed on the local terminal are sent to the remote server and executed there. The credential provides a text-based interface, generating a remote command and connection to achieve the user’s goals.

An SSH key is a quick reference, an access credential, or when someone needs to figure out how to configure their server in different ways and connect. Their function is similar to assigning usernames and passwords, but these keys are useful in automated processes and for implementing single sign-on by advanced users and system administrators.

Would you like to know how an SSH key is generated and what to do to configure it? Follow this content!

Understand what the SSH key is and what it is for

Secure Shell (SSH) keys are authentication credentials used to manage operating systems, networks, and configurations. They are within the file transfer and configuration management tools. The data centers of large corporations use these resources that allow automation, which is capable of making cloud services more modern and economical.

Other computer-dependent solutions also rely on SSH keys, which offer greater security and convenience when managed properly. They grant access and control to who can access what in a computerized system, with the help of policies and identity management, user accounts, and access. Without this solution, it is not possible to have data integrity and confidentiality.

Technically, SSHs are cryptographic keys that use a public key system to identify users. Therefore, they are authentication credentials and need to be managed to determine who is authorized to access environments and are similar to the locks that private keys can perform.

Find out what the elements of the SSH key are

The SSH private identity keys that a client uses to log in and authenticate to a server are similar to the physical keys that can open locks. Taken together, authorized and identification keys are opposed to host keys.

See below for more details that make up the Secure Shell keys!

Device keys

Host keys authenticate servers and computers to prevent attacks known as man-in-the-middle. This authentication is certificate-based and can be a very attractive option for large organizations.

The solution enables all connections to be secured and device authentication keys to be rotated and managed conveniently.

Host Keys

One of the unique features of the SSH key is that, by default, the tool remembers the host key when connecting for the first time. This is an important difference that allowed the solution to be implemented locally, as there was no centralized infrastructure for hosts in 1995.

Memorized host keys are recognized and stored in a file called known_hostsOpenSSH. If they are not changed, the approach is very easy to use and provides reasonably good security. Ease of deployment was one of the main reasons the SSH key became successful.

Session keys

A session key can be used to encrypt most data during a connection. SSH is negotiated during access and then used with a message authentication code algorithm and a symmetric encryption algorithm to protect data.

Check out how an SSH key is generated and what to do to configure it

It is easy to perform SSH key-based default configuration. Typically they are configured in an author_keys.ssh file in the user’s home directory subdirectory. See other tips :

  • create a key using ssh-keygen;
  • install it as an authorized key on a server using the ssh-copy-id tool;
  • use passwords for all identity keys used for interactive and automated access;
  • store keys in ssh-agent for single sign-on;
  • use the program called ssh-agent to keep decrypted private keys in memory and authenticate logins;
  • see the ssh-agent documentation to configure it;
  • enable agent forwarding;
  • set in AllowAgentForwarding/etc/ssh/sshd_config on the server and in the client configuration file /etc/ssh/ssh_config .yesForwardAgentyes.

The location of the identity key is in the user’s .ssh directory. The identity key file name starts with id_<algorithm>. You will be able to specify any location and any file name and provide the path name when creating a private key, for example, ssh -i /home/ylo/secure/my-key ec2-user@awshost.domain.myusaria.

Discover the main commands that help with SSH configuration

To connect to a remote machine, you need to have the IP address and load the terminal. Type SSH followed by the IP address, for example, SSH, or the name like SSH Check out some commands for connecting to the host below!


Use ssh-add when you need to tell SSH which key you want to use for authentication. This command adds private key identities from your SSH directory to the SSH-agent authenticator agent. This way you won’t have to type passwords into the terminal.


SCP stands for Secure Copy Protocol, which is a command-line utility used by users to securely copy directories and files to two locations, typically between Linux and Unix systems.


SFTP is the acronym for the term SSH File Transfer Protocol, which transfers files between remote systems securely. If you want to create a user on your system that will be used for file transfer only, you need to create a specific directory to provide access to the directory.


SSH Vault allows users to securely connect to different machines and environments to perform several distinct operations. Using the SSH key can be difficult to manage between teams and corporate businesses, but the solution is secure for automating access.

Understand the advantages of SSH keys over passwords

SSH are secure keys used to manage configurations, networks, operating systems, and private data. They are one of the best security systems.

Note the main advantages of these solutions:

  • ease of configuration on your system;
  • easy and quick access revocation according to requirements;
  • accessibility across multiple systems without sharing passwords;
  • simplified permissions management.

Did you understand how to configure the SSH key? This tool is essential to ensure that systems are not accessible to malicious users and prevents unauthorized people from gaining access to computers. Private keys can be encrypted with a password in interactive logins for non-automated tasks.

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