Digital signatures are the digital alternative of physical signatures. They use a mathematical algorithm to verify the document owner’s identity and to authenticate the document. This algorithm also makes it possible to trace the origin of a document and ensure that the content of the document is kept intact throughout the transfer process. Each document has a unique digital signature attached to it. A digital signature also includes information about the origin, the status and consent of the signature owner.
A digital signature certificate or commonly known as digital signatures are the most frequently used faster, secure and more convenient alternative to physical signatures. Anyone can create a digital signature online by registering for a Digital Signature Certificate (DSC) under a Certifying Authority. Among the many purposes of Digital signature, it has been incorporated into the workflow of many businesses because of these three main reasons :
1. Security : Digital signatures do not carry any fear of forgery or its content getting tampered once signed by the owner. Before the signing of a digital document, the signer’s identity is verified, hence if a digital document is ever forged, it will never make it through because each digital document contains the unique signature of the sender.
2. Time efficient : Anyone can easily sign a document in minutes without any fear of tampering. The extra time can be utilized in improving the workflow.
3. Cost efficient : Digital signatures cut off the additional costs like paper printing, mailing, traveling etc. thus making it favorable for people to exchange documents from anywhere and at any time without spending a single penny.
The mathematical algorithm which is unique to digital signatures makes it the safest portal for signing documents online. Let us now understand the process which makes digital signatures work.
1. The Hash function : Every time an individual signs a digital document a hash value is produced. This value is a fixed-length series of letters which is subject to change with any change made in the content of the document.
2. Public Key Cryptography : Digital signatures uses a cryptographic algorithm to generate two asymmetric keys, the public key and the private key. These keys ensure the safe transfer of a document for both the sender and the end recipient. One key is used to encrypt the data and the other is used to decrypt it. A private key is always unique to the owner of a digital signature. While the public key can be shared with the public to open and view the message.
3. Public Key Infrastructure (PKI) : The PKI ensures that all the policies, standards of a public key cryptography are maintained during the process of sending and receiving a digital document.
4. Certifying Authority (CA) : In many cases, a third party, who acts as the certifying authority also comes into action. They validate the identity of the signer and a recipient. Digital Signature Certificates are issues for the validation process.
5. Digital Signature Certificate : It is a digital document that verifies the identity of individuals involved in a digital transaction. A digital signature certificate is signed and authorized by a Certifying Authority (CA).