PuTTYgen is what you will use to generate your SSH keys for use in PuTTY. PuTTYgen is a (free) open-source utility and can be downloaded from the maintainer's website. However, PuTTY does have a companion named PuTTYgen (an RSA and DSA key generation utility), that can convert OpenSSH private key files into PuTTY's format allowing you to connect to your cloud server from a Windows machine, with the added security that SSH keys provide.

Consequently, PuTTY does not have native support for reading OpenSSH's SSH-2 private key files. While PuTTY is a client program for SSH (in addition to Telnet and Rlogin), it is not a part of or otherwise based on OpenSSH. RSA is the only recommended choice for new keys, so this tutorial uses 'RSA key' and 'SSH key' interchangeably. Both of these were considered state-of-the-art algorithms when SSH was invented.īut DSA has come to be seen as less secure in recent years. SSH can use either 'RSA' (Rivest-Shamir-Adleman) or 'DSA' ('Digital Signature Algorithm') keys. Other authentication methods are only used in very specific situations. Key-based authentication is the most secure of several modes of authentication usable with OpenSSH, such as plain passwords and Kerberos tickets. Today, OpenSSH is the default SSH implementation on Unix-like systems such as Linux and OS X. Click here to check the Best Putty AlternativeĮvery computer has (i) a public and (ii) a private 'key' (two mathematically-linked algorithms that are effectively impossible to crack). While a password can eventually be cracked with a brute-force attack, SSH keys are nearly impossible to decipher by brute force alone. This is because SSH keys provide a more secure way of logging in compared to using a password alone.

If your headless, or remote, VPS is visible over the Internet, you should use public key authentication instead of passwords, if at all possible.

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