What is MAC?
MAC is a service which is used for the authentication of message, checks the integrity of message. MAC uses a secret key for the purpose of encryption. It takes the key and the message as input and produces the authentication code as the input.
Requirements of MAC
• Traffic analysis
• Content modification
• Sequence modification
• Timing modification
• Source repudiation
• Destination repudiation
It describes about the process of release of contents of the message to the person who is not having the appropriate cryptographic key.
It determines the patterns of traffic among the parties who are in the connection oriented network. It can be determined also in the connection less network.
In this the attacker may indulge the unwanted message contents in in the network. This may lead to the fraudulence in the communication channel.
It leads to the modification of messages in the communication channel which are sent to receiver from sender.
It involves the process of modifying the sequence of messages.
It describes the replay or delay of messages which are sent from sender to receiver.
It describes the process of denial of services from the sender side
It describes the process of denial of services from the receiver side.
MAC provides the service in the following different ways.
This service is used in the context of symmetric encryption and provides confidentiality and the authentication.
This service is used in the context of public key encryption and provides confidentiality.
This service is used in the context of symmetric encryption and provides authentication and the signature.
This service is used in the context of symmetric encryption and provides authentication the signature and confidentiality.
MAC can also be combined with hash to provide the different feature; the algorithm which is developed by them is HMAC. MAC is also combined with the block cipher in order to develop the DAA, CMAC like algorithms. In fact HASH and MAC are combinedly used to generate pseudo random generators.