SSL and SSH sound similar and could easily be used interchangeably.
But what is the difference between SSL and SSH?
Are they directly comparable?
Are they variations on the same thing?
Often one is used when it ought to be the other. Is this correct?
SSL
SSL is a secure protocol for establishing links between networked computers. These links are authenticated and encrypted.
The most visible use of SSL is the padlock in the browser address bar showing that communication with a website is encrypted.
A certificate is assigned to a website to enable it to operate securely. An SSL certificate is used to bind the identity of a website to a cryptographic key pair, comprising a public and private key. Utilising the public key within the certificate the web browser can initiating communication.
Certificates can be self-signed where the authentication of the certificate is not to be referenced. There are paid for certificates and the LetsEncrypt free certificate.
SSL has been superseded by TLS (Transport Layer Security).
SSH
SSH is a network protocol, dating from 1995.
Its generally used to remotely connect with servers to make changes, updates and run apps. These tasks may be automated with one computer/server connecting to another at specified times of the day.
SSH encompasses the utilities which implement the protocol. There’s a strong password authentication, a public key authentication, and encrypted date a communications.
As a cryptographic protocol it provides a secure channel over an unsecure network enabling communication between a client and server.
There have been two major versions SSH-1 and SSH-2.
Further Reading
Wikipedia: secure shell
Wikipedia: Transport Layer Security
