What is a hardware security module used for?

• A. Storing regular user passwords in plaintext.
• B. Acting as a firewall for networks.
• C. Providing general server computation.
• D. Providing a secure set of cryptographic services and key-management functions, including decryption of account data.

Answer: (D)

A hardware security module is a specialized device designed to protect cryptographic keys and perform cryptographic operations in a secure, tamper-resistant environment. It securely generates, stores, and manages keys, and carries out tasks such as encryption, decryption, signing, and key lifecycle management, all while ensuring keys aren’t exposed to potentially compromised systems. This makes it the right choice for providing a secure set of cryptographic services and key-management functions, including decryption of account data, because sensitive operations happen inside the hardware with strong access controls and auditability. The other options don’t fit: storing passwords in plaintext is insecure by design, a firewall protects networks rather than performing cryptographic processing, and general server computation isn’t focused on safeguarding keys or performing cryptographic operations.