What is the difference between SSL and SSH? The key difference between SSH vs SSL is that SSH is used for creating a secure tunnel to another computer from which you can issue commands, transfer data, etc. On the other end, SSL is used for securely transferring data between two parties – it does not let you issue commands as you can with SSH.
Does SSH use TCP or UDP? Is SSH over TCP or UDP? SSH usually runs over TCP. That being said, RFC 4251 specifies that SSH transmission layer protocol “might also be used on top of any other reliable data stream”. SSH protocol’s default settings are to listen on TCP port 22 for connections.
Does SSH require a key? SSH key pairs are two cryptographically secure keys that can be used to authenticate a client to an SSH server. Each key pair consists of a public key and a private key. The private key is retained by the client and should be kept absolutely secret.
Are SSH keys tied to user? ssh/authorized_keys. In short although the keys are not physically connected to user or host, it’s probably best to treat them as if they were.