Benefits of the Digital Signature
There are basically two benefits that encourage the use of this tool:
1. Authentication:
Although messages may usually include information regarding the sender, that information is not always precise.
Digital signatures are used to authenticate the source of the message.
When a proprietor of a secret key for a digital signature is linked to a specific user, a valid signature shows that the message was sent by that specific user.
The importance of high confidence regarding authenticity of the message sender is reinforced specially in a financial context.
2. Integrity
When both the sender and recipient of a message need to be assured that the communication has remained unaltered during delivery, this benefit becomes crucial.
Although encryption hides the contents of the message, it is possible to change the encryption of a message without understanding it (some algorithms prevent this, others don’t).
Nevertheless, if a message is digitally signed any alteration thereafter would turn the signature invalid.
Even more, there aren’t any efficient ways of modifying a message and its signature to produce a new one with a valid signature, since this is considered computationally impossible by many cryptographic functions, known as Hash.