Before you set Access Control for an Amazon S3 Bucket using Bucket Explorer, we strongly recommend that you read this page and understand the implications. In most cases, you will never need to set Bucket ACL as "read all" . That statement is true even when you are using a bucket for web hosting.

1. Permissions set for a Bucket do NOT automatically propagate to files stored in that Bucket.
2. "Read" permission at Bucket level does NOT mean that the authorized user can read all the files in that Bucket . Read permission at Bucket Level means that "list bucket" command is authorized on a bucket. Which essentially means that if you give "read" permission on a bucket to everyone then everyone can list the file names, their size and last modified date from that bucket.

Access Control List

Amazon S3 allows users to store their files in Buckets. All Buckets and Files are associated with Access control policies. ACL is a mechanism which decides who can access what. This option gives you access to ACLs of particular bucket. Here you can not only see your ACLs but also can update them. ACLs are excellent way to control the way buckets are accessed by other Amazon users and normal users. When you alter any bucket's ACL, Program informs you about changes and asks your permission whether to proceed with the changes. This facility makes sure that you have not made any change accidentally.

Update ACL Access Control for Bucket

1. To update Access Control List for Bucket/File you have to select particular Bucket/File.
2. Right Click on selected Bucket/File.
3. You will get a form showing current ACLs of that Bucket/File.
4. These ACLs are shown in Table and that table contains at least 4 rows for Bucket (owner, Authenticated Users, All Users and Log Delivery) and 3 rows for file (owner, Authenticated Users, All Users). Row could be more then specified number
5. you can make S3 files public readable by clicking on Make Public button
   
   OR
   
   You can also make private S3 files ( private ACL setting is set by default ) by clicking on Make Private button
   
   OR
   
   You can change ACLs according to your requirement by simply checking or un-checking checkbox.
   
   
6. When there are no changes done in ACL & you click on save, then Permissions remain identical and it won’t do any changes but it shows message.
   1. Message for identical/changed ACLs case of bucket : “Permission has been saved for bucket”
   2. Message for identical ACLs case of File : “Permission is Identical for: <file name>”
   3. Message for changed ACLs case of Files : “Permission updated for : <file name>”.
      

You don't need to pay any cost for update ACL if the permissions are identical.