Encryption is method of scrambling data in some manner during transmission. In periods of war, the use of encryption becomes paramount so those messages are not intercepted by the opposing forces. There are a number of different ways to protect data during transmission, such as Substitution (character for character replacement) in which one unit (usually character) of cipher text (unintelligible text or signals produced through an encryption system) is substituted for a corresponding unit of plain text (the intelligible text or signals that can be read without using decryption), according to the algorithm in use and the specific key.
The other method is Transposition (rearrangement characters) which is the encryption process in which units of the original plain text (usually individual characteristics) are simply moved around; they appear unchanged in the cipher text for their relative location.
Study Case (Bank of Shenandoah Valley)
While both encryption and authentication method are providing some measures of security, the implementation of security itself has totally a different approach. Before any methods chosen, the two most important factors in security implementations are having to be determined. The level of security needed and the cost involved, so the appropriate steps can be taken to ensure a safe and secure environment. In this case Bank of Shenandoah Valley is in type of business which a high level of security is required, therefore, I would suggest the use of encryption method with a complex algorithm involved.
Although an authentication method is a secure method as well, is not as complex as encryption method of complex algorithm since it has been used in military during the war where a high levels of security are a must. During the war, the use of encryption becomes paramount so those messages are not intercepted by the opposing forces. This is a perfect example of how reliable an encrypted message can be while used within its appropriates guidelines.
4- Describe the three different database models – hierarchical, relational and network.
For data to be effectively transformed into useful information, it must be organized in a logical, meaningful way. Data is generally organized in a hierarchy that starts with the smallest unit (or piece of data) used by the computer and then progresses into the database, which holds all the information about the topic. The data is organized in a top – down or inverted tree likes structure. At the top of every tree or hierarchy is the root segment or element of the tree that corresponds to the main record type.
The hierarchical model is best suited to situations in which the logical relationship between data can be properly presented with the one parent many children (one to many) approach. In a hierarchical database, all relationships are one – to -one or one- to – many, but no group of data can be on the ‘many’ side of more than one relationship.
Network Database is a database in which all types of relationships are allowed. The network database is an extension of the hierarchical model, where the various levels of one-to-many relationships are replaced with owner-member relationships in which a member may have many owners. In a network database structure, more that one path can often be used to access data. ‘Databases structured according to either the hierarchical model or the network model suffers from the same deficiency: once the relationships are established between the data elements, it is difficult to modify them or to create new relationships.
Relational Database describes data using a standard tabular format in which all data elements are placed in two-dimensional tables that are the logical equivalent of files. In relational databases, data are accessed by content rather than by address (in contrast with hierarchical and network databases). Relational databases locate data logically, rather than physically. A relational database has no predetermined relationship between the data such as one-to-many sets or one-to-one.
Case study ( D’Angelo Transportation, Inc.)
There are a number of factor which ought to be discussed during discussion:
O How much of the system should by computerized?
O Should we purchase software or build based on what we are using in the current system. ( make versus buy analysis)
O If we decide to make the new system, should we design an on-line or batch system?
O Should we design the system for a mainframe computer, minicomputer, microcomputers or some combinations?
O What information technologies might be useful for this application?
Some of the security issues, are consist of the level of security required and the cost involved in this conversion. A database system is vulnerable to criminal attack at many levels. Typically, it is the end user rather the programmer who is often (but not always) guilty of the simple misuse of applications. Thus, it is essential that the total system is secure. The two classifications of security violations are malicious or accidental.
One of the most emphasized and significant factors of any program development is the early involvement of the end-users. This provides the programmer as well as the end-user with important functionality of the new system and help them to adapt to the new working environment more efficiently and effectively. The continuos training of the staff is essential in meeting the objectives of the organization since they will be provided with needed skills and expertise necessary to deal with daily issues using of new system.