When creating a data connection, I'm getting the infamous ENCRYPTION_KEY_MISSING error message that I've seen several posts (post 1, post 2, post 3, post 4) discussing. I am aware of this support article that talks about how to generate an encryption key. I'm aware of the Setting an encryption key documentation which talks about how to set an encryption key.

What I can't seem to find is an explanation of what is an encryption key in the context of data connections and how Qlik Sense is using it.

This Community post suggests that an "encryption key" is a private key of an SSL certificate. This support article, however, suggests that using rand -base64 256 OpenSSL command, which to my understanding is a simple random string generator, will generate an "encryption key".

With that as the context, what is an encryption key? Is it a private key of an SSL certificate? Is it a random string? Is it either? Is it something else? Does anyone know?