A Hardware Security Module (HSM) is a physical device that provides a secure environment for cryptographic operations such as the generation, management, storage, and protection of encryption keys. HSMs are designed to prevent tampering and unauthorized access, often used by enterprises to enhance security for transactions, identities, and applications. On the other hand, a Trusted Platform Module (TPM) is also a hardware device that assists in secure generation of cryptographic keys, but it is commonly used to secure the computing platform itself rather than for managing keys for user authentication. A Key Management System is typically a software solution rather than a dedicated hardware device, and a Secure Enclave, while it provides additional security within a processor, does not have the primary purpose of managing multiple cryptographic keys for user authentication.