Cloud Security

Cloud computing introduces unique security challenges. Understanding the shared responsibility model, cloud-specific threats, and security controls is essential for protecting cloud environments.

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Cloud Service Models

Model	You Manage	Provider Manages	Example
IaaS	OS, apps, data, middleware	Hardware, virtualisation, network	AWS EC2, Azure VMs, GCP Compute
PaaS	Applications and data	OS, runtime, middleware, hardware	Heroku, Azure App Service, Google App Engine
SaaS	Data (and sometimes config)	Everything else	Microsoft 365, Salesforce, Google Workspace

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The Shared Responsibility Model

Security in the cloud is shared between the cloud provider and the customer:

┌─────────────────────────────────────────────────┐
│                Customer Responsibility           │
│  ┌────────────────────────────────────────────┐  │
│  │  Data, Identity, Access, Configuration     │  │
│  │  Application Security, Encryption Keys     │  │
│  │  Network Security (security groups, NACLs) │  │
│  │  OS Patching (IaaS only)                   │  │
│  └────────────────────────────────────────────┘  │
├─────────────────────────────────────────────────┤
│                Provider Responsibility           │
│  ┌────────────────────────────────────────────┐  │
│  │  Physical security, Hardware, Networking   │  │
│  │  Hypervisor, Storage infrastructure        │  │
│  │  Global infrastructure, Availability       │  │
│  └────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────┘