The role of session key

1. John started a tutorial class to handle electronic gadgets easily in a shopping mall. His business runs well. He planned to conduct online classes in Internet and hosted an application. He got a merchant account from national credit card company. To provide more payment options to his customer, he wants to go with PayPal. What are the various kind of operations that happen with PayPal and in its absence? Suggest your overall opinion to John in this scenario. 7. State the basic steps in PGP. 8. Discuss the role of PGP in E-mail security. 9. Give a sample for hash algorithm.

2. What is the role of session key in PGP encryption?