You can improve the security of your sign in to AWS services, such as Amazon WorkSpaces and Amazon QuickSight, by enabling multi-factor authentication (MFA) when using AWS Directory Service for Microsoft Active Directory (Enterprise Edition), also known as Microsoft AD. Enabling MFA helps improve the security of your applications because users must enter a one-time passcode (OTP) in addition to their Active Directory (AD) user name and password. AWS Microsoft AD supports both virtual and hardware MFA OTP tokens.