This may sound weird: What if I don't let others know my public key, then use my private key to encrypt, and the public key to decrypt? Is this secure? Let me explain a little bit:
Common usuage: use private key to sign and disclose public key, then others can vefriy the data signature use public key
Weird usage: use private key to encrypt and don't disclose public key, in other end use public key to decrypt. notice here I will not disclose private key either so it's not swap In second scenario, if I can keep both keys secure(I mean don't disclose to otheres), does it secure?