6. Assume Alice uses S/Key and a seed x to generate 200 one-time passwords for her to login into the EBay server. Please answer the following questions:

6.1: After the 200 passwords are created by Alice running free software, Alice is going to use them in a particular order. What is the 106th password that Alice will use to login into the EBay server? Please justify your answer with sufficient details. (15 points)

6.2 After each one-time password is used by Alice, the EBay server will update its password file accordingly. After the 5th password used to login is used by Alice and after the password file is updated, what is stored in the password file (on the EBay server)? Please justify your answer with sufficient details. (15 points)

6.3: After the 22nd password used to login into the server is used by Bob, John, the bad guy, steals his 87th password. Among the 200 - 22 = 178 passwords left for Bob to use, how many can still be used by Bob without worrying about attacks? Please justify your answer with sufficient details.