Encrypt each user's data before storing it on the hard disk
4. You have been hired to provide advice about the use of cryptography to the developer of new two products within a company.

a. Group A is developing a product which will encrypt each user's data before storing it on the hard disk, and decrypt it as it is accessed. Confidentially should be preserved. They want to know what encryption algorithms to use, and how it should be used to achieve their goals. What advice would you give this group?

b. Group B is developing a product which will allow users to send encrypted messages to other users around the world. Users typically do not know each other directly, but they should be able to send messages for which integrity and confidentiality are preserved. They want to know what encryption algorithm(s) to use, and how it (they) should be used to achieve the goals. What advice would you give this group? 

9. An enterprising group of entrepreneurs is starting a new data storage and retrieval business, StoreItRite, Inc. For a fee, the new company will accept digitalized data (both text and images), and store it on hard drives until needed by the customer. Customer data will be transmitted to and from StoreItRite over the Internet. StoreItRite guarantees that the data's confidentiality and integrity will be maintained.
StoreItRite also envisions some information assurance requirements for their internal operations. Company employees will need to exchange confidential email, and will need a mechanism for verifying the integrity and originator of some email messages. Also, StoreItRite intends a daily backup of all customer data to a remote facility via a leased line. They wish to do so as economically as possible, while ensuring the data's confidentiality and integrity. 
StoreItRite is interviewing candidates for the position of Chief Information Officer (CIO). They are asking candidates to describe briefly how they would satisfy StoreItRite's requirements as stated above. How would a successful candidate respond?