A _________ protects against an attack in which one party generates a message for another party to sign

Head of ____ is one of key presidential appointments

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

If a witness to an accident states, "That car was going fast; probably 60 miles per hour," that witness is:

A) testifying. B) stating a fact. C) giving an opinion. D) giving a deposition.