Normally (in production) , you would need to pay a "certificate authority " to issue a '''certificate ''' for you. Thatis essentially '''s essentially a "signed " public key ''' that will tell strangers on the internet that your server is really yours (i.e. the certificate authority says so). There's is an obvious problem with the previous statement statemen,t but that's mostly is mainlyy how public key encryption works on the internet Internet today.

We'll will be generating our ownpublic keys, mostly mainly in order to avoid paying for the a certificate. We won't will not have too much enough time to get into the details of what all the following commands doin this section. They are from [https://www.e-rave.nl/create-a-self-signed-ssl-key-for-postfix this blog post]. If you don't understand what he's talking about on that page the blog post refers to but would like to understand - I'll again recommend the in more details, a good recommended book for interest, called Crypto by Steven Levy for reading outside this course, provides a more in-depth discussion of encryption and security.

The public key cryptography concepts in this lab are the same in this lab as the SSH a previous lab(), but although the terminology is slightly different.  A simple way to look at it summarize the differences is::* The '''.key''' file is your private key.:* The '''.crt''' file is your public key.