# Request Authentication
<a name="RequestAuthentication"></a>

**Topics**
+ [What Is Authentication?](WhatIsAuthentication.md)
+ [Creating an AWS Account](AboutAWSAccounts.md)
+ [Managing Users of Amazon SimpleDB](UsingIAMWithSDB.md)
+ [Using Temporary Security Credentials](UsingTemporarySecurityCredentials_SDB.md)
+ [HMAC-SHA Signature](HMACAuth.md)

This section explains how Amazon SimpleDB authenticates your requests.