To understand the process of how digital signature works and why it has become an essential form of authorization in certain cases, it is important to know about the main components of a digital signature.
The first and foremost thing that a digital signature includes is the name of the individual who is using the signature or authorizing a digital document for distribution/access. This is important so as to reduce any chances of fraud that may be caused by another person sharing the same name.
Apart from the full name of the user, a digital signature should also contain various contact information such as telephone number, a valid email address and contact address that may be used to locate the person. This data is however encrypted and not accessible by every individual so as to ensure privacy of the user.
Another very important component of a digital signature is a public key. This is unique to each digital signature issued/generated. This key is used for encryption of the document being authorised and is essential for the verification process. The expiry date of a digital signature is also determined by its public key. This implies the time frame for which a particular digital signature will be valid. Public key is also useful in case you need to reset the signature, if necessary.
Serial number is another key component that acts as a unique identifier of a digital signature. This serial number is used by a certification authority who issues the digital certificate. This number is of prime importance to ensure the viability of a digital signature.