AWS S3 (and Auth Methods) for Azure Folks

Amazon S3 is something akin to Azure Blob Storage. 

A quick revision of Azure Blob Storage: 

Azure Blob Storage is a general-purpose cloud storage option for cloud native workloads.  

It supports WORM operating scenarios (Write Once Read Many) aka WORM-compliant storage (which prevents data from being edited or deleted). Role based access control (RBAC) is supported as is authentication with Microsoft Entra (formerly Azure Active Directory).

Amazon S3 (Simple Storage Service) is a similar offering in AWS.

The services are exposed as a web service with a custom HTTP scheme known as keyed-HMAC (Hash Message Authentication Code).  A more "high level" authentication option is available via AWS IAM.

Securing Azure - A Multifaceted Problem

The following guide gives many dimensions to consider when securing an Azure environment.

At the storage level, Azure Storage supports the use of Azure Active Directory and role-based access control (RBAC). 

Storage service encryption means data at rest is protected. 

The OS disk used by virtual machines can in turn be secured via Azure Disk Encryption (ADE). ADE has no specific additional costs, but there is a cost for putting keys in the Azure key vault.

Servicing data subject requests (DSRs) in the context of EU GDPR, in the context of a secure Azure environment, is detailed here.