1. What do you think are the advantages and disadvantages of using a special-purpose device rather than a mobile phone in two-factor authentication? (Hint: Think about the problems of using a mobile...

1. What do you think are the advantages and disadvantages of using a special-purpose device rather than a mobile phone in two-factor authentication? (Hint: Think about the problems of using a mobile phone as an authentication device.) 2. What is the difference between symmetric and asymmetric encryption? Why do we need both encryption methods?