Which cloud service category is MOST likely to use a client-side key management system?

In IaaS, customers have significant control over the operating system and applications, allowing them to implement server-side or customer-managed key management within their allocated resources.

In a SaaS model, the customer typically has the least control over the application and underlying infrastructure, making client-side key management crucial for maintaining data confidentiality and compliance. This allows customers to encrypt their sensitive data before uploading it to the SaaS application, ensuring the cloud provider never possesses the unencrypted data or the encryption keys, thereby addressing strict regulatory or privacy requirements.

In PaaS, customers manage their applications and data, giving them more options for integrating key management solutions directly into their application stack rather than relying solely on client-side encryption.

DaaS (Desktop as a Service) is a specific type of SaaS, and while it might involve client-side key management for certain data, SaaS broadly represents the category where such a solution is most common for protecting data from the provider.