The best option for ensuring confidentiality through the use of asymmetric encryption is to encrypt a message with the recipient’s public key (option A). This is because:
Asymmetric encryption, also known as public-key cryptography, is a type of encryption that uses a pair of keys to encrypt and decrypt data. The pair of keys includes a public key, which can be shared with anyone, and a private key, which is kept secret by the owner12.
In asymmetric encryption, the sender uses the recipient’s public key to encrypt the data. The recipient then uses their private key to decrypt the data. This approach allows for secure communication between two parties without the need for both parties to have the same secret key12.
Encrypting a message with the recipient’s public key ensures that only the recipient can decrypt it with their private key. This provides confidentiality, which means that the message is protected from unauthorized access or disclosure12.
Encrypting a message with the sender’s private key (option B) does not ensure confidentiality, but rather authentication, which means that the message can be verified as coming from the sender. This is because anyone can decrypt the message with the sender’s public key, but only the sender can encrypt it with their private key12.
Encrypting a message with the sender’s public key (option C) or the recipient’s private key (option D) does not make sense, as it would render the message unreadable by both parties. This is because neither party has the corresponding key to decrypt it12.
Therefore, the best option for ensuring confidentiality through the use of asymmetric encryption is to encrypt a message with the recipient’s public key (option A), as this ensures that only the recipient can decrypt it with their private key.
[References: 1: What is asymmetric encryption? | Asymmetric vs. symmetric … - Cloudflare 2: What is Asymmetric Encryption? - GeeksforGeeks, , , , ]
