Information
While logged in, the keychain does not prompt the user for passwords for various systems and/or programs. This can be exploited by unauthorized users to gain access to password protected programs and/or systems in the absence of the user.
Solution
Perform the following to implement the prescribed state:
Open Utilities
Select Keychain Access
Select a keychain
Select Edit
Select Change Settings for keychain <keychain_name>
Authenticate, if requested.
Select Lock when sleeping setting