A company that provides a cloud-based storage solution for consumers needs to ensure that users' data is encrypted while it is stored on its premises. Which of the following should be used to…

SSL (Secure Sockets Layer) is a cryptographic protocol that uses symmetric and asymmetric encryption to protect data confidentiality. Among the available options it is the only choice that performs encryption rather than hashing or authentication. While SSL is commonly associated with data in transit, it represents the encryption mechanism needed to ensure stored consumer data remains unreadable to unauthorized parties.

HMAC (Hash-based Message Authentication Code) is used to verify message integrity and authenticity using a shared secret, but it does not encrypt data and cannot protect the confidentiality of stored information.

SHA (Secure Hash Algorithm) is a one-way cryptographic hash function used for integrity verification and digital signatures - it cannot encrypt data or restore original plaintext, so it provides no confidentiality protection.

RC4 is a deprecated stream cipher with well-documented cryptographic weaknesses including key-scheduling vulnerabilities that make it fundamentally insecure for protecting stored data in any modern environment.