Which of the following is the most effective method to ensure data confidentiality when transmitting sensitive information over a public network?

Public-key encryption using the recipient’s public key is the best choice for ensuring data confidentiality during transmission. This method leverages asymmetric encryption, where the recipient’s public key is used to encrypt the data, and only the recipient can decrypt it using their private key. This ensures that even if the data is intercepted during transmission, it cannot be read by unauthorized parties without access to the recipient's private key. For example, when a user sends an email encrypted with the recipient's public key, only the recipient can decrypt it, preserving confidentiality. Asymmetric encryption also avoids the risk of key compromise associated with pre-shared keys in symmetric encryption. Moreover, it scales better for secure communication across multiple parties because each participant needs only one pair of keys (public and private) instead of maintaining numerous shared keys. Why Other Options Are Incorrect:

• A) Symmetric encryption relies on a shared secret key. If the key is intercepted, the data is compromised.
• B) Using the sender’s private key ensures authenticity but does not protect confidentiality because anyone with the sender’s public key can decrypt the data.
• D) Hashing only ensures data integrity, not confidentiality, as it does not allow for data reconstruction or encryption.
• E) A one-time pad is secure in theory, but improper key management makes it impractical for real-world applications.