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Network Security |
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There are several protection alternatives, including the use of passwords, use of security modems and encryption/decryption. The most secure and effective are the encryption/decryption types. Historical information Encryption or cryptography was used for military purposes since the Roman empire (of course without the use of computers!). Nowadays, cryptography is done by computers since it will be very easy for computers to crack a man-made cryptography. |
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What is encryption/decryption? "Enryption is the translation of data into a secret code." Decryption is the changing back of encrypted code (or cipher text) to plain text. A key or password is necessary for encryption and decryption. While encryption is done at the transmitting end so that unauthorised users who will access the data through the network will not be able to understand the data, decryption is done at the receiving end so that the receiver will be able to read the data. 
There are two main encryption/decryption processes:  public key encryption
symmetric encryption |
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Public key encryption This uses two keys: a private key known only to the receiving computer, and a public key known to anyone who wants to communicate securely with the computer. A message encrypted using the public key can be decrypted using the private key, and vice versa. A popular implementation of the public key encryption is the Secure Socket Layer (SSL), which was originally developed by Netscape. |
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Symmetric encryption
This uses the same private key to encrypt and decrypt the data. Although this is faster, the disadvantage is that both the sender and receiver of information must have access to the same key, thus secure distribution of keys must be implemented, which is difficult. |
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