Computer Security 2

Chapter # 5 1 - Define encryption and explain how it is used to protect transmission of info rmation. 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 no t intercepted by the opposing forces. There are a number of different ways to p rotect data during transmission, such as Substitution (character for character r eplacement) in which one unit (usually character) of cipher text (unintelligible text or signals produced through an encryption system) is substituted for a cor responding 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 k ey. The other method is Transposition (rearrangement characters) which is the encryp tion process in which units of the original plain text (usually individual chara cteristics) are simply moved around; they appear unchanged in the cipher text fo r their relative location. Study Case (Bank of Shenandoah Valley) While both encryption and authentication method are providing some measures of s ecurity, the implementation of security itself has totally a different approach. Before any methods chosen, the two most important factors in security implemen tations 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 envi ronment. 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 encryp tion method with a complex algorithm involved. Although an authentication metho d 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 perfec t example of how reliable an encrypted message can be while used within its appr opriates guidelines. Chapter # 6 4- Describe the three different database models - hierarchical, relational and n etwork. For data to be effectively transformed into useful information, it must be organ ized in a logical, meaningful way. Data is generally organized in a hierarchy t hat starts with the smallest unit (or piece of data) used by the computer and th en 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 t he top of every tree or hierarchy is the root segment or element of the tree tha t corresponds to the main record type. The hierarchical model is best suited to situations in which the logical relationship between data can be properly prese nted with the one parent many children (one to many) approach. In a hierarchica l 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 vario

us levels of one-to-many relationships are replaced with owner-member relationsh ips in which a member may have many owners. In a network database structure, mo re that one path can often be used to access data. "Databases structured accord ing 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 equivale nt of files. In relational databases, data are accessed by content rather than by address (in contrast with hierarchical and network databases). Relational da tabases locate data logically, rather than physically. A relational database ha s 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: Ø How much of the system should by computerized? Ø Should we purchase software or build based on what we are using in the current s ystem. ( make versus buy analysis) Ø If we decide to make the new system, should we design an on-line or batch system ? Ø Should we design the system for a mainframe computer, minicomputer, microcompute rs or some combinations? Ø What information technologies might be useful for this application? Some of the security issues, are consist of the level of security required and t he cost involved in this conversion. A database system is vulnerable to crimina l attack at many levels. Typically, it is the end user rather the programmer wh o is often (but not always) guilty of the simple misuse of applications. Thus, i t is essential that the total system is secure. The two classifications of secu rity 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 a s the end-user with important functionality of the new system and help them to a dapt to the new working environment more efficiently and effectively. The conti nuos training of the staff is essential in meeting the objectives of the organiz ation since they will be provided with needed skills and expertise necessary to deal with daily issues using of new system.