Question

What kind of requirements need to be achieved for massage authentication? What kind of methods are normally used to achieve such requirements?

Answer 1

Message authentication is a way of verifying the received messages, whether they are from an alleged source or whether the messages are altered or not.

Requirements:

1. Disclosure - the release of message contents to a person or process not containing the proper cryptographic key.
2. Traffic analysis - determining the frequency and duration of connection in a connection-oriented application or the length of messages between parties in a connection-less application.
3. Content modification - changing the contents of a message.
4. Timing modification - delayed or replayed messages.
5. Source repudiation - denial of transmission of a message by source.
6. Destination repudiation - denial of transmission of a message by destination.

Methods:

One of the methods includes a digital signature, an authentication technique that measures for counter check the source and destination.

Other methods could be using Message Authentication Code (MAC). MAC generated by an algorithm, the receiver performs computation on the message and checks whether it matches the MAC, for which the sender assures that the message was unaltered and comes from the sender.