The external paging device is usually __________.

______ enables the reuse of existing classes.

a) Encapsulation b) Inheritance c) Polymorphism d) Simulation

An encryption scheme is _________ if the cost of breaking the cipher exceeds the value of the encrypted information and/or the time required to break the cipher exceeds the useful lifetime of the information.

Fill in the blank(s) with the appropriate word(s).