SCS-C02 Identity and Access Management Practice Question
A developer needs to grant an IAM user temporary access to an S3 bucket for 15 minutes. Which AWS service should be used to generate temporary credentials?
⚠ Common exam trap
SCS-C02 often tests whether candidates confuse key-management services with credential-issuing services; the trap is selecting KMS because it 'manages keys,' when the question is about temporary IAM credentials, which only STS provides.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
AWS Security Token Service (STS)
AWS Security Token Service (STS) is the service that issues temporary, limited-privilege credentials via APIs like AssumeRole, GetSessionToken, and GetFederationToken. To grant an IAM user temporary access to an S3 bucket for 15 minutes, you call STS AssumeRole (or GetSessionToken) with a DurationSeconds value of 900, and STS returns an access key, secret key, and session token that expire automatically.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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AWS Certificate Manager (ACM)
Why it's wrong here
AWS Certificate Manager (ACM) provisions and rotates public/private TLS certificates for use with integrated AWS services like CloudFront and Application Load Balancer, enabling HTTPS encryption. It does not participate in user authentication or authorization, and it cannot mint credentials for API access, temporary or otherwise. Therefore ACM is unrelated to granting an IAM user temporary access.
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AWS Key Management Service (KMS)
Why it's wrong here
AWS KMS is a managed service that creates, stores, and controls customer master keys used for cryptographic operations such as encrypting data at rest or in transit. It can enforce key policies and grant permissions for cryptographic operations, but those permissions are distinct from STS-issued credentials and do not provide the caller with a temporary AWS access key, secret key, and session token. KMS would never be used to give an IAM user temporary AWS API access.
- ✓
AWS Security Token Service (STS)
Why this is correct
AWS Security Token Service (STS) is the service that issues short-lived credentials composed of an access key ID, secret access key, and session token, exactly what an IAM user needs for temporary access. By calling sts:AssumeRole (or GetFederationToken), the developer can request a role's permissions for a configurable duration and receive credentials that expire automatically. This matches the requirement: STS is the correct service for granting temporary access to AWS resources.
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AWS Directory Service
Why it's wrong here
AWS Directory Service provides managed Microsoft Active Directory domains, enabling your workload to authenticate users against LDAP and Kerberos protocols in the AWS cloud. It handles enterprise identity directories and can integrate with IAM roles for single sign-on, but it does not itself issue AWS API credentials with session tokens. Since the question asks for a service that grants an IAM user temporary access to AWS, Directory Service is not the correct choice.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
Related to this question
About these practice questions
Courseiva writes every SCS-C02 question from scratch — 1,205 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
This SCS-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SCS-C02 exam.