11 - Amazon S3 Security

Amazon S3 Security - Section Overview

awss3securityencryptionsaa-c03

Section Map

This section covers Amazon S3 security features building on the fundamentals from S3 Introduction and advanced topics from Advanced S3. Security is one of the most heavily tested S3 topics on the SAA-C03 exam.

# Topic Key Concepts
01 S3 Encryption SSE-S3, SSE-KMS, SSE-C, client-side encryption, encryption in transit, DSSE-KMS, default encryption
02 S3 CORS Cross-Origin Resource Sharing, preflight requests, Access-Control-Allow-Origin headers
03 S3 MFA Delete Multi-factor authentication for permanent deletions, root account requirement
04 S3 Access Logs Server access logging, audit trail, logging loop warning
05 S3 Pre-signed URLs Temporary access, URL expiration, GET/PUT use cases
06 Glacier Vault Lock & S3 Object Lock WORM model, compliance mode, governance mode, legal hold, retention periods
07 S3 Access Points Simplify security management, access point policies, VPC origin
08 S3 Object Lambda Modify objects on retrieval, redact PII, enrich data, Lambda access points

Key Exam Topics

  • Encryption types — know when to use SSE-S3 vs SSE-KMS vs SSE-C vs client-side
  • KMS throttling — SSE-KMS counts against KMS API quotas (5,500–30,000 req/s)
  • CORS — must enable correct CORS headers on the target S3 bucket for cross-origin requests
  • MFA Delete — only root account can enable/disable, requires versioning
  • Pre-signed URLs — temporary access to private objects (console: 12h, CLI: 168h)
  • Object Lock — compliance mode (nobody can delete) vs governance mode (admins can override)
  • Access Points — simplify bucket policy management at scale
  • S3 Object Lambda — transform objects on retrieval without duplicating buckets

Check yourself

Quiz