What type of authentication requires two different forms of verification including something you have and something you know?

The correct answer is multifactor authentication, which is a security measure that requires users to provide two or more verification factors to gain access to a resource. This method enhances security by combining different types of authentication factors: something you have (like a mobile device or hardware token) and something you know (like a password or PIN).

Using multifactor authentication significantly reduces the risk of unauthorized access, as it is significantly more difficult for an attacker to possess both types of factors needed for authentication. This method is widely adopted in various environments, especially in cloud services and sensitive applications where data protection is paramount.

The other options do not incorporate the specific requirement for two different forms of verification. Single Sign-On allows access to multiple applications with a single set of login credentials, but it does not require multiple forms of verification. Confederations typically refer to a grouping of federated identity systems, which also do not emphasize dual-factor verification. Active Directory/LDAP are directory services that facilitate user authentication and authorization but, again, do not pertain specifically to the multifactor approach.