We have got this message below when trying to connect via SSH, WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED

I had overwritten my previous key in my computer and used it with a new droplet (not the one I tried to connect when getting this message. That one actually asks for a password I have not received via e-mail)

Thinking that this message was probably related to that, I updated my SSH key in Azure with that new one from my computer again. But the message continued to show when trying to login in via ssh.

Awnser

Use ssh-keygen to delete the invalid key

Example:

By Windows Cygwin:

Post reference ssh.com.

By linux:

ssh-keygen Option Summary

Here is a summary of commonly used options to the keygen tool:

  • -b “Bits”
    This option specifies the number of bits in the key. The regulations that govern the use case for SSH may require a specific key length to be used. In general, 2048 bits is considered to be sufficient for RSA keys.
  • -e “Export”
    This option allows reformatting of existing keys between the OpenSSH key file format and the format documented in RFC 4716, “SSH Public Key File Format”.
  • -p “Change the passphrase” This option allows changing the passphrase of a private key file with [-P old_passphrase] and [-N new_passphrase], [-f keyfile].
  • -t “Type” This option specifies the type of key to be created. Commonly used values are: – rsa for RSA keys – dsa for DSA keys – ecdsa for elliptic curve DSA keys
  • -i Input When ssh-keygen is required to access an existing key, this option designates the file.
  • -f File Specifies name of the file in which to store the created key.
  • -N New Provides a new passphrase for the key.
  • -P Passphrase Provides the (old) passphrase when reading a key.
  • -c Comment Changes the comment for a keyfile.
  • -p Change the passphrase of a private key file.
  • -q Silence ssh-keygen.
  • -v Verbose mode.
  • -l Fingerprint Print the fingerprint of the specified public key.
  • -B Bubble babble Shows a bubble babble (Tectia format) fingerprint of a keyfile.
  • -F Search for a specified hostname in a known_hosts file.
  • -R Remove all keys belonging to a hostname from a known_hosts file.
  • -y Read a private OpenSSH format file and print an OpenSSH public key to stdout.