4. In cryptography what is the difference between a symmetric algorithm and an asymmetric algorithm? (5 marks) 5. A hacker has gained access to a password file containing password hashes for millions of accounts. (a) How might the hacker determine whether the passwords have been salted? (5 marks) (b) Assuming the password file has not been salted, how might the hacker use this infor- mation to greatly increase the chance of cracking a password? (6 marks)