Alice needs to send a confidential document to her coworker. Bryan. Their company has public key infrastructure set up. Therefore. Alice both encrypts the message and digitally signs it. Alice uses___

Using Bryan's public key for both blanks fails because signature verification requires the signer's public key - Bryan must use Alice's public key, not his own, to confirm Alice's signature.

Encrypting with Alice's own public key provides no confidentiality for Bryan specifically, since any party holding Alice's public key could also decrypt the message.

Private keys are never used to encrypt confidential messages intended for a recipient - encrypting with Bryan's private key would allow any holder of Bryan's public key to decrypt the content, defeating confidentiality entirely.

Alice uses Bryan's public key to encrypt the message so that only Bryan, possessing the corresponding private key, can decrypt and read it. Bryan then verifies Alice's digital signature using Alice's public key, confirming the signature was produced by Alice's private key and establishing authenticity and non-repudiation.