IAM Explained: Identity and Access Management in the Cloud

Identity and Access Management (IAM) is the cornerstone of cloud security. It defines who can access what resources and under what conditions. Understanding IAM is essential for securing any cloud environment.

What is IAM?

IAM is a framework of policies and technologies that ensures the right individuals have appropriate access to technology resources. In cloud computing, IAM controls access to cloud services and resources.

Core IAM Concepts

Identities

Identities represent entities that can be authenticated:

• Users: Individual people who need access
• Groups: Collections of users with similar access needs
• Service Accounts: Non-human identities for applications and services
• Roles: Temporary identities that can be assumed

Authentication

Authentication verifies identity through:

• Passwords (something you know)
• MFA tokens (something you have)
• Biometrics (something you are)
• Certificates (cryptographic proof)

Authorization

Authorization determines what authenticated identities can do:

• Policies: Documents that define permissions
• Permissions: Specific actions allowed on resources
• Resource-based policies: Permissions attached to resources
• Identity-based policies: Permissions attached to identities

IAM Best Practices

1. Implement Least Privilege

Grant only the permissions necessary to perform a task. Start with minimal permissions and add more as needed, rather than starting broad and restricting.

2. Use Groups and Roles

Instead of assigning permissions to individual users:

• Create groups based on job functions
• Assign permissions to groups
• Add users to appropriate groups
• Use roles for cross-account access

3. Enforce Multi-Factor Authentication

MFA significantly reduces the risk of account compromise. Require MFA for:

• All console access
• Privileged operations
• Access to sensitive data

4. Use Temporary Credentials

Prefer temporary credentials over long-term access keys:

• Use IAM roles for EC2 instances and Lambda functions
• Implement role assumption for cross-account access
• Rotate credentials regularly if long-term keys are necessary

5. Monitor and Audit

Regularly review IAM configurations:

• Enable logging for all IAM activities
• Review permissions periodically
• Remove unused credentials and permissions
• Alert on suspicious IAM changes

Common IAM Mistakes to Avoid

1. Using root/admin accounts for daily tasks
2. Sharing credentials between team members
3. Granting wildcard (*) permissions
4. Not rotating access keys regularly
5. Ignoring inactive users and permissions
6. Hardcoding credentials in applications

IAM Across Cloud Providers

While the concepts are similar, each cloud provider has its own IAM implementation:

• AWS IAM: Users, groups, roles, and policies with JSON syntax
• Azure AD: Users, groups, service principals, and RBAC roles
• GCP IAM: Members, roles, and policies with hierarchical inheritance

Understanding IAM deeply is essential for cloud security. Take time to learn your cloud provider's IAM system thoroughly before deploying production workloads.