Fix The Authenticity of Host Not Verified Error

The chances that if you have installed open SSH newly on Linux Mint, you will encounter the error message “the authenticity of host cannot be verified” are high. Encountering this error message does not always mean that you have used the wrong host setup. Rather than panic, stay calm; this error message is normal for users connecting to a host for the first time.

This article will provide information on the “host’s authenticity not verified issue,’’ and profer solutions to resolve it.

What do I Do When I Encounter Authenticity of Host not Verified Error?

When you encounter the SSH error stating “Authenticity of host not verified,” it shouldn’t be a source of worry to you. The error occurs when you try to log in to a new system. It is aimed at verifying the network. So at the point where it asks if you trust the server, you can input your answer.

In the future, your computer will automatically remember your choice and not ask you the question again. Before inputting your answer, you should always compare the key provided against the key on the server. In reality, most people don’t bother with this step, but we advise you to follow it.

The real benefit is that subsequently, you wouldn’t get the SSSH complaint. If you do get the SSH complaint regarding a server you have already inputted as trusted, then there is a high chance that you are under a MiTM attack.

If you are on a network you trust and are confident that you are not under the Man in The Middle attack, and this is the first time you are connecting to the computer, you can rest easy knowing it is safe to accept the key.

I Keep Encountering the Authenticity of Host Not Verified Error, What Can I Do?

If you keep getting this authenticity verification issue when you connect to a new host, you should know it is normal. When you see the prompt asking if you want to continue, follow these steps.

Step 1: Select yes to continue connecting.

Step 2: Add the host’s fingerprint value to the home directory. To do this, enter the command line: ~/.ssh/known_hosts

Step 3: Check if the host’s fingerprint value has been properly added. For this, open up ~/.ssh/known_hosts via the command line nano ~/.ssh/known_hosts. You can open it in Nano or even another text editor. Superuser

Step 4: After this, select yes, then run the SSH command again. Once again, answer yes to the prompt, then check it out again. You will find the added host’s hash/fingerprint value at the bottom of the file.

One benefit of these hashes is that it protects the host from fraudulent third parties. For example, in the case of an attempted man-in-the-middle attack on the host, the host’s fingerprint value will automatically change and cause SSH to whip up an even more panicked warning to alert you of the proposed encroachment.

What to Do When You See Permission Denied?

If this error comes with an additional message about permission being denied, then it is likely that a wrong password has been entered. Entering the wrong password can trigger this error and may even present with the error message “root permission is not permitted.”

In this case, you should try to re-enter the correct password. If you cannot recall your password details, you can reset it easily by going to the access tab on the droplet page. If this does not work, check if the password authentication is disabled.

For this, you will need to log onto the droplet via web control. Once logged in, check the password authentication settings in the configuration file. Use the command: the /etc/ssh/sshd_config file. Superuser

What Does Man in the Middle Attack Mean?

A man-in-the-middle (MitM) attack occurs when there is a malicious intercept of communications between third-parties. The aim is to modify traffic secretly and obtain private information. These attackers use the attacks to steal personal information, login credentials, corrupt data, and spy or sabotage communications.

Put plainly, MitM happens when the hacker inserts his device in between your device and the webserver. Although you can guard against MitM by encrypting sensitive information, some attackers get around the protection encryption offers by rerouting traffic to fake sites. These fake or phishing sites are made to look legitimate. These smart moves make detecting these attacks extremely difficult.

How Does Man in the Middle Attack Operate?

MitM attack is among the oldest forms of cyberattacks. MitM attacks involve spying or manipulating traffic information. This manipulation may be via interfering with legitimate networks or even creating artificial ones under the attacker’s control. Such traffic can then be rid of encryptions and stolen, rerouted, or redirected to the attacker’s destination.

MitM encompasses a wide range of methods. The techniques used and the outcome all depend on the target victim and the goal. In SSL stripping, for example, the attackers will often create an HTTPS connection between the victim, themselves, and the server. With an unsecured HTTP connection with the user, information is sent as plain text without encryption.

For the evil twin attack, the technique employed is the mirroring of authentic Wi-Fi access points. These access points are, however, controlled entirely by malicious actors. With this, they can now track, collect, and even manipulate information sent by users.

Who is at risk?

Everybody using a mobile device is a target. However, the most vulnerable people are individuals in the top or executive positions in government and business.

These hackers are very cunny and are constantly on the lookout for people with access to important or sensitive information like trade secrets, financial data, etc. 

What Can I Do to Protect Myself?

Standard protection methods like secure wrappers, containers, and mobile anti-virus solutions often do not do enough to protect you from these cyber threats. This is so because each day, new forms of MitM spring up, and old techniques continue to evolve. To protect yourself from these new attacks being discovered regularly, you much take appropriate measures.

 The best protection, of course, is to prevent it from occurring in the first place. To protect yourself from these attacks, employ these methods.

  • While using mobile apps, ensure you validate the hostname
  • Ensure the certificate found to tally with the hostname server’s, and ensure the correct root authority trusts the certificate. Without doing this, there’s no way for the app or device to know if its data is being hijacked and sent to another website. Apple and Android have made this validation easier for users
  • Don’t set your device to auto-connect to unknown sources. 
  • Also, avoid the use of free Wi-Fi hotspots and automatic connections. 


The authenticity of the host not verified error is nothing you should panic over. In most cases, occurs when you try to sign in to a new system. Another reason for this message could be the suspected Man in The Middle attack. Use the tips provided in this article to rid yourself of this error and protect yourself from the MiTM attack.