Secure Store Service in SharePoint 2010

Secure Store Service:
The Secure Store Service is an authorization service that runs on an application server. The Secure Store Service provides a database that is used to store credentials. These credentials usually consist of a user identity and password, but can also contain other fields that you define. For example, SharePoint Server 2010 can use the secure store database to store and retrieve credentials for access to external data sources.
Secure store used for following scenarios:
Excel services,Visio services, Performance point services, PowerPivot for SharePoint 2010, BCS.
Backup the SSS DB once it is newly created and after every generating of new encryption key.

SSA creation:
Create a new service account --> Register the account in Configured Managed account in Central admin --> Recommend is not to set for Automatic password change --> Start the SSS service through "Manage services on server" central admin -->  Application Management section, click Manage service applications --> New -->  click SSS --> Enter the name of of SSA --> Enter the SQL server name and the DB name  --> Enter the name of new application pool --> Select configurable

Generate new on Encrption key:
Open the SSA --> click on Generate New Key under Ker management --> On the Generate New Key page, type a pass phrase string in the Pass Phrase box, and type the same string in the Confirm Pass Phrase box.

A target application is a collection of information that maps a user or users to a set of encrypted credentials stored in the Secure Store database.Storing credentials in Secure Store is accomplished by using a Secure Store target application. A target application maps the credentials of a user, group, or claim to a set of encrypted credentials stored in the Secure Store database. After a target application is created, you can associate it with an external content type or application model, or use it with a Business Intelligence Service Application such as Excel Services or Visio Services to provide access to an external data source. When a SharePoint Server 2010 service application calls the target application, Secure Store confirms that the user making the request is an authorized user of the target application and then retrieves the encrypted credentials. The credentials are then used on the user’s behalf by the SharePoint Server 2010 service application.

Create target application:
Manage service application--> Click SSA --> Manage Target application --> New --> Target Application ID --> enter the a unique string --> Enter the test string in Display name --> Enter an email ID -->use default page/custom page/None --> Select Group or Individual from Target Application Type drop down --> Next --> Specify the credential fields for your Secure Store Target Application --> Add two listed fields -->Specify the membership settings.