What is the MOST secure way to share the documents with the external users?
Use S3 presigned URLs to share the documents with the external users. Set an expiration time of 7 days.
Move the documents to an Amazon WorkDocs folder. Share the links of the WorkDocs folder with the external users.
Create temporary IAM users that have read-only access to the S3 bucket. Share the access keys with the external users. Expire the credentials after 7 days.
Create a role that has read-only access to the S3 bucket. Share the Amazon Resource Name (ARN) of this role with the external users.
Explanations:
S3 presigned URLs provide a secure way to share documents for a limited time. By setting an expiration time of 7 days, the links will automatically become invalid after that period, ensuring that access is time-limited and secure.
While Amazon WorkDocs allows sharing documents, it does not provide the same level of temporary access control as presigned URLs. Additionally, moving documents to WorkDocs may introduce additional complexity and security considerations.
Creating temporary IAM users with access keys poses security risks, as sharing access keys can lead to misuse. Even with an expiration mechanism, it is less secure than using presigned URLs, as it grants broader access to the S3 bucket rather than temporary, limited access to specific objects.
Sharing the ARN of a role does not allow external users direct access to the S3 bucket. They would need AWS credentials to assume the role, which complicates access management and does not provide the intended temporary access to documents.
From what I’ve heard, the answer is:
Use S3 presigned URLs to share the documents with the external users. Set an expiration time of 7 days.