public key encryption - When generating or exporting a GPG private key, what is 'secret subkey'?

Question

Let's say I generate a secret PGP key using gpg --gen-key
I enter name: John Doe, and email: johndoe@example.com, it asks for a passphrase, and then generates the key.

When I do gpg --list-keys the new key is there.

Now when I export the key using gpg --export-secret-key johndoe@example.com it asks for the passphrase to export the OpenPGP secret key. When I click cancel, it asks again for the passphrase, this time to export the OpenPGP secret subkey.

What is this 'secret subkey', how does it differ from the main or regular secret key?

When I export the public key, i.e. the thing I can send to others, I use this:
gpg --armor --export johndoe@example.com

And then I get something that looks like a base64 encoded public key. But it's just one key. Which part is this, the main key or subkey? Or is there no difference when dealing with the public side of things?

question from:https://stackoverflow.com/questions/66066178/when-generating-or-exporting-a-gpg-private-key-what-is-secret-subkey

Answer 1

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