Which one (ones) of the following statements is (are) correct? __________

1.  The protection profile should be written in a device-dependent way.

2.  "Danger" and "Risk" can be defined using the probability concept.

3.  "Hack" only refers to the activity that causes users harm.

4.  The concepts of authenticity and integrity are equivalent. 

5.  There should not be ambiguity in the safety policy.