Computer security is a process of protecting computer system and information from harm and unauthorized use. The most important security tool beyond human integrity used is cryptography. Cryptography is used to hide data from public view and to ensure that the integrity and privacy of any data sent across a network has not been compromised. This project work helps you to understand what cryptography is all about and the procedures used to achieve this aim, it explains the design and implementation of computer security: data encryption and decryption and key hash algorithm. The programming language used in the development of this project is Microsoft, in this project the researcher achieved all she has in mind in designing this program by making sure that the integrity and the privacy of an individual is not compromise. In conclusion, security in communication and network system have come a long way to ensure that information transmitted between two or more parties involved in a conversation enjoys the benefits of privacy. The researcher suggested that developers and engineers need to research more on computer security in order to provide a stronger security unit on information and data.


In the past, security was simply a matter of locking the door or storing files in a locked filing cabinet or safe. Today, paper is no longer the only medium of choice for housing information. Files are stored in computer databases as well as file cabinets. Hard drives and floppy disks hold many of our secret information.

In the physical world, security is a fairly simple concept. If the locks on your house’s doors and windows are so strong that a thief cannot break in to steal your belongings, the house is secure. For further protection against intruders breaking through the locks, you might have security alarms. Similarly, if someone tries to fraudulently withdraw money from your bank account but the teller asks for identification and does not trust the thief’s story, your money is secure. When you sign a contract with another person, the signatures are the legal driving force that impels both parties to honor their word.

In the digital world, security works in a similar way. One concept is privacy, meaning that no one can break into files to read your sensitive data (such as medical records) or steal money (by, for example, obtaining credit card numbers or online brokerage accounts information). Privacy is the lock on the door. Another concept, data integrity, refers to a mechanism that tells us when something has been altered. That’s the alarm. By applying the practice of authentication, we can verify identities. That’s comparable to the ID required to withdraw money from a bank account (or conduct a transaction with an online broker). And finally, non-repudiation is a legal driving force that impels people to honor their word.

As the Internet becomes a more pervasive part of daily life, the need for e-security becomes even more critical. Any organization engaged in online activity must assess and manage the e-security risks associated with this activity. Effective use of cryptographic techniques is at the core of many of these risk-management strategies. The most important security tool is cryptography.


  1. To understand and improve the computer data security through encryption of data.
  2. To provide  a means of safeguarding data in a system
  3. To enhance the integrity of data
  4. To facilitate the use of more sophisticated tool against hacking, cracking, bugging of a system.
  5. To develop a platform to complement physical security.