A digital signature is an electronic form of a signature that can be used to authenticate the identity of the sender of a message or the signer of a document, and also ensure that the original content of the message or document that has been sent is unchanged. Digital signatures are easily transportable and cannot be imitated by someone else. The ability to ensure that the original signed message arrived
means that the sender cannot easily disclaim it later.

Digital Signature Certificates (DSC) is the electronic format of physical or paper certificate like a driving License, passport etc. Certificates serve as proof of identity of an individual for a certain purpose; for example, a Passport identifies someone as a citizen of that country; who can legally travel to any country. Likewise, a Digital Signature Certificate can be presented electronically to prove your
identity, to access information or services on the Internet or to sign certain documents digitally.

A Digital Signature Certificate authenticates your identity electronically. It also provides you with a high level of security for your online transactions by ensuring absolute privacy of the information exchanged using a Digital Signature Certificate. You can use certificates to encrypt information such that only the intended recipient can read it. You can digitally sign information to assure the recipient
that it has not been changed in transit, and also verify your identity as the sender of the message.

Legally valid Digital Signature Certificates are issued only through a Controller of Certifying Authorities (CCA), Govt. of India, licensed Certifying Authorities (CA).

You can use Digital Signature Certificates for the following:

• For sending and receiving digitally signed and encrypted emails.
•  For carrying out secure web-based transactions, or to identify other participants of web-based transactions.
•  In eTendering, eProcurement, MCA [for Registrar of Companies efiling], Income Tax [for efiling income tax returns] Applications and also in many other applications.
• For signing documents like MSWord, MSExcel and PDFs.
• Plays a pivotal role in creating a paperless office.

A Digital Signature Certificate explicitly associates the identity of an individual/device with a pair of electronic keys – public and private keys – and this association is endorsed by the CA. The certificate contains information about a user’s identity (for example, their name, pin code, country, email address, the date the certificate was issued and the name of the Certifying Authority that issued it).
These keys complement each other in that one does not function in the absence of the other. They are used by browsers and servers to encrypt and decrypt information regarding the identity of the certificate user during information exchange processes. The private key is stored on the user’s computer hard disk.