Hardware security modules (HSMs) provide the foundation of modern asymmetrical and symmetrical encryption, tokenization, digital signature, and time stamping. They offer an impenetrable “Fort Knox” for managing digital certificates and performing cryptographic operations and play an integral role in payment security. This report examines key use cases, integration points, established and new requirements for HSMs, and highlights how HSMs must evolve for the post-quantum cryptography (PQC) era.