maintain the integrity of information, authentication of legal users, and availability of data.
             Possible threats and dangers to the Networks
             A threat to confidential data on computers comes from both inside and outside users. It may be intentional or unintentional and accidental. There are also passive and active threats. Passive threats are those where only secure information is accessed without affecting the system (Computer Security, 1998). In case of active threats, both information and system are affected (Computer Security, 1998) and this is mostly intentional.
             Threats could be from hackers who masquerade for accessing secure data or spreading virus. Repetition and modification of messages. Insider attacks could come from the loss of confidential secure data by authorized users where as outsider attacks are intentional site invasion or data access by illegitimate users. Creation of trap doors that allow unauthorized person to access information. Virus attacks that may damage important data, files and hardware. Exhaustion attacks to access passwords or any other encrypt data. Other accidental failures including hazards to equipment and systems. For e.g., power failures, rain/snow/air storm, earthquakes etc.
             Protection from external threats include implications of following measures:
             Encryption is to encode the information into an unreadable format using specific mathematical key. In this way message cannot be read in the hands of unauthorized persons. Only authorized person having the same matching key can decrypt and read the message.
             There are different encryption models for encrypting/decrypting files. These models in turn have variable keys, coming in various size and numbers. The smaller the key, the easier is to crack the message. Therefore, for very secure and confidential information, larger and tougher keys should be used to encode and decode the messages.
             Two types of keys are important for encryption s...