How does encryption work

I turned on encryption for my form to see how it would work, then turned it off again because I had a few questions. I downloaded the encryption key and saved it -- then I tested the form and received the email notification telling me I had received an encrypted response, and when I clicked the button in the email, I was able to view the submission ... but I'm not sure how this works -- do I just have to keep the "key" document on my computer and by having it there, I'm able to view the encrypted submissions? What if I'm on another computer that doesn't have the "key" document on it, can I only view submissions from the computer that has the "key" document (or a copy of it) saved to its hard drive? What happens if I delete the "key" document from my computer, will I no longer be able to view submissions? Also, since I turned encryption off, if I turn it back on again, should I choose to provide my own key and use the one I already downloaded, or will I need to request for JotForms to provide a new key? Thanks for your help.

In order to view an encrypted notification, you need to upload the encryption key to your browser. If had not uploaded the private key to your browser, and the data was already decrypted, could it be possible that you had added the Preview Before Submit widget? That widget can cause conflicts with the encryption process and the data will not be encrypted. 

Please check this complete guide about encrypted forms before implementing this feature: https://www.jotform.com/help/344-Encrypted-Forms-and-How-to-Use-Them