Final answer:
The security protocol Kerberos is used to enforce strong passwords, account locking, and password expiration policies. It uses tickets and symmetric key cryptography for secure communication in potentially unsafe networks.
Step-by-step explanation:
The security protocol used to provide security policies such as strong passwords, account locking, and password expiration is Kerberos. HTTP (HyperText Transfer Protocol) and TCP/IP (Transmission Control Protocol/Internet Protocol) are not primarily focused on user authentication or policy enforcement like Kerberos. Kerberos is a network authentication protocol designed to provide strong authentication for client/server applications by using secret-key cryptography. A major benefit of Kerberos is its ability to provide secure authentication over open networks where there might be threats of eavesdropping and replay attacks.
Kerberos accomplishes this by utilizing tickets and symmetric key cryptography to authenticate users to services and vice versa. When it comes to creating security policies for passwords, such as enforcing strong passwords, setting password expiration periods, and implementing account locking mechanisms after a series of failed login attempts, these functionalities are typically managed by the network or system administrators within an organization's IT infrastructure, often leveraging capabilities provided by the authentication system, in this case, Kerberos.