Cryptographic services
User Authentication
If you log to a computer system there must (or at least should) be some way that you can convince it of your identity. Once it knows your identity, it can verify whether you are entitled to enter the system. The same principal applies when one person tries to communicate with another: as a first step you want to verify that you ar communicating with the right person. Therefore there must be some way in which you can prove your identity. This process is called user authentication. There are several ways to obtain user authentication.
Data Authentication
Data authentication consists of two components: the fact that data has not been modified (data integrity) and the fact that you know who the sender is (data origin authentication).
Data Integrity
A data integrity service guarantees that the content of the message, that was sent, has not been tampered with. Data integrity by itself is not meaningful: it does not help you to know that the data you have received has not been modified, unless you know it has been sent directly to you by the right person. Therefore it should always be combined with data origin authentication.
If you log to a computer system there must (or at least should) be some way that you can convince it of your identity. Once it knows your identity, it can verify whether you are entitled to enter the system. The same principal applies when one person tries to communicate with another: as a first step you want to verify that you ar communicating with the right person. Therefore there must be some way in which you can prove your identity. This process is called user authentication. There are several ways to obtain user authentication.
Data Authentication
Data authentication consists of two components: the fact that data has not been modified (data integrity) and the fact that you know who the sender is (data origin authentication).
Data Integrity
A data integrity service guarantees that the content of the message, that was sent, has not been tampered with. Data integrity by itself is not meaningful: it does not help you to know that the data you have received has not been modified, unless you know it has been sent directly to you by the right person. Therefore it should always be combined with data origin authentication.