HashiCorp Vault is a secrets and encryption management system that can help organizations comply with the new PCI DSS v4.0 requirements by providing secure and auditable access to sensitive data, including cardholder data. The system validates and authorizes clients before providing them access to secrets or stored sensitive data, ensuring tight control over access and recording detailed audit logs. Vault addresses several key PCI requirements, including securing configuration and management of systems, protecting account data, encrypting transmission over public networks, and defining processes for strong cryptography during transmission. To leverage Vault effectively for PCI compliance, organizations must integrate it into a broader compliance strategy that includes training, regular audits, and ongoing monitoring of their systems and processes.