08-12-2012, 05:02 PM
NETWORK SECURITY
[attachment=43109]
WHAT IS NETWORK SECURITY
NETWORK SECURITY is becoming more and more crucial as the volume of data being exchanged on the internet increases.
When people use the internet ,they have certain expectations .
They expect confidentiality and data integrity.
They want to be able to identify the sender of a message .
They want to be able to prove that a message has in fact sent by a certain sender even if the sender denies it.
PRIVACY
PRIVACY means that the sender and receiver expect confidentiality .
The transmitted message should make sense to only the receiver . To all others, the message should be unintelligible.
AUTHENTICATION
Authentication means that the receiver is sure of the sender’s identity and that an imposter has not sent the message.
INTEGRITY
DATA INTEGRITY means that the data must arrive at the receiver exactly as it was sent . There must be no changes during the transmission ,either accidental or malicious . As more and more monetary exchanges occur over the internet , integrity is crucial. For example , it would be disastrous if a request for transferring $100 changes to a request for $10,000 or 100,000. The integrity of the message must be preserved in a secure communicaton.
Non-repudiation
Non-Repudiation means that a receiver must be able to prove that a received message came from a specific sender. The sender must not be able to deny sending a message that he, in fact , did send. The burden of proof falls on the receiver. For example , when a customer sends a message to transfer money from one account to another, the bank must have proof that the customer actually requested this transaction.
How privacy can be acheived ?
ENCRYPTION/DECRYPTION:-
The data to be encrypted at the sender site is called plaintext. The encrypted data is called cipher text and is decrypted at the receiver .
There are two categories of encryption /decryption methods: the secret key method and the public key method
PRIVACY WITH SECRET KEY ENCRIPTION/DECRYPTION
The same key is used by both parties.
The sender uses this key and an encryption algorithm to encrypt data; the receiver uses the same key and the corresponding decryption algorithm to decrypt the data.
The algorithm used for decryption is the inverse of the algorithm used for encryption. E.g. if the encryption algorithm uses a combination of addition and multiplication ,the decryption algorithm uses a combination of division and subtraction.
Note:----it also referred to as symmetric encryption algorithms because the same secret key can be used in bidirectional communication.
[attachment=43109]
WHAT IS NETWORK SECURITY
NETWORK SECURITY is becoming more and more crucial as the volume of data being exchanged on the internet increases.
When people use the internet ,they have certain expectations .
They expect confidentiality and data integrity.
They want to be able to identify the sender of a message .
They want to be able to prove that a message has in fact sent by a certain sender even if the sender denies it.
PRIVACY
PRIVACY means that the sender and receiver expect confidentiality .
The transmitted message should make sense to only the receiver . To all others, the message should be unintelligible.
AUTHENTICATION
Authentication means that the receiver is sure of the sender’s identity and that an imposter has not sent the message.
INTEGRITY
DATA INTEGRITY means that the data must arrive at the receiver exactly as it was sent . There must be no changes during the transmission ,either accidental or malicious . As more and more monetary exchanges occur over the internet , integrity is crucial. For example , it would be disastrous if a request for transferring $100 changes to a request for $10,000 or 100,000. The integrity of the message must be preserved in a secure communicaton.
Non-repudiation
Non-Repudiation means that a receiver must be able to prove that a received message came from a specific sender. The sender must not be able to deny sending a message that he, in fact , did send. The burden of proof falls on the receiver. For example , when a customer sends a message to transfer money from one account to another, the bank must have proof that the customer actually requested this transaction.
How privacy can be acheived ?
ENCRYPTION/DECRYPTION:-
The data to be encrypted at the sender site is called plaintext. The encrypted data is called cipher text and is decrypted at the receiver .
There are two categories of encryption /decryption methods: the secret key method and the public key method
PRIVACY WITH SECRET KEY ENCRIPTION/DECRYPTION
The same key is used by both parties.
The sender uses this key and an encryption algorithm to encrypt data; the receiver uses the same key and the corresponding decryption algorithm to decrypt the data.
The algorithm used for decryption is the inverse of the algorithm used for encryption. E.g. if the encryption algorithm uses a combination of addition and multiplication ,the decryption algorithm uses a combination of division and subtraction.
Note:----it also referred to as symmetric encryption algorithms because the same secret key can be used in bidirectional communication.