Digital signature & DSC

Digital signature & DSC

Last Updated : Nov. 23, 2022, 3:07 p.m.

An electronic signature (e-signature) known as a digital signature uses public-key cryptography to provide identity authentication and offer data and transaction integrity.

The origin, identity, and status of electronic documents, transactions, or digital messages can be verified using digital signatures. They can also be used by signers to confirm informed consent.

The most frequent illustration is a wet signature that is scanned by a machine and then put into a document. Another illustration of a basic digital signature is the email signature we frequently include at the bottom of emails and the terms and conditions box we check during program installation.

How do Digital Signatures work?

Digital signatures operate by showing that a digital message or document has not been altered—intentionally or unintentionally—since it was signed. To accomplish this, digital signatures create a special hash of the message or document and encrypt it with the sender’s private key. Since the created hash is specific to the message or document, any changes to it will result in an entirely new hash.

The completed letter or digital document is then forwarded to the recipient after being digitally signed. The recipient then creates the hash of the message or digital document and uses the sender’s public key to decode the sender’s hash, which was contained in the original message. The message or digital document has not been altered, and the sender is verified, if the recipient matches the hash they create to the sender’s encrypted hash.

What are digital signature certificates?

A digital signature certificate, also known as a DSC, is a key that is cryptographically secure and is provided by certifying authorities (CAs) to validate and confirm the identity of the person who has the certificate.

To securely authenticate the signature and validate the signed document, DSCs are generally issued and used by organisations when they need to sign documents online digitally.

In any location where the certifying authorities support Aadhaar eKYC-based authentication, applicants may likewise obtain DSCs.

Along with these techniques, a letter that includes the applicant’s information for an online signing certificate as it is stored in the bank’s database may also be utilised. The bank manager needs to certify these documents.

Why is it required?

A DSC or digital Signature Certificate makes it possible for signatures to be made on electronic forms and online documents, much like there are physical documents for manual signatures.

The certificate digitally verifies the signer’s identity. In addition to these features, a DSC provides a high level of security for online transactions by guaranteeing the confidentiality of the data on the eSigned document.

Users can encrypt data so that only the intended receiver can access it using a digital signature certificate. An eSignature certificate guarantees that the document was not altered while in transit and establishes the sender’s identity.

How does DSC work?

  • A digital signature certificate directly links a set of electronic keys to a specific person’s identity. The pair consists of a private key and a public key that have the Certifying Authority’s approval (CA).
  • Information regarding the user’s identification is contained in the DSC. It contains details like the name, nation, PIN code, email address, date the certificate was granted, and the name of the certifying authority.
  • The electronic keys are approved by CAs as a pair. They are complementary to one another, and one cannot exist without the other. During the information exchange procedure, browsers and servers utilise these keys to encrypt and decrypt the data about the certificate user’s identity.
  • The user’s device or an external token stores the public key linked to the digital certificate. The user maintains control over the private key, which can only be used with the assigned password.
  • The public key is distributed together with encrypted data. If the public and private keys do not match or if one of them is unavailable, the authentication process for the eSigned document will fail.
  • By making the document inaccessible to unauthorised persons, this encryption technique assures that the encrypted data cannot be deciphered by them.

Positive aspects of digital signature certificates

  • The authentication of the document is secure: A DSC assists in highly authenticating the personal information of the individual bearer during digital commercial transactions.
  • Authenticity: The certificate assures the receiver that the signature on the document is that of the designated signatory. Without having to worry about it being forged, they can proceed with the digitally signed document.
  • Decreased time and expense: A digital signature certificate holder doesn’t need to be physically present to execute or approve a commercial transaction. As a result, less time and money are needed to execute a transaction.
  • The reliability of the data: After being electronically signed, the document cannot be changed or updated thanks to a digital signature certificate. This increases the security of the records, which are frequently quite private.
  • Simple Verification: If necessary, government agencies can quickly verify the business transaction by requesting the DSC from either the certificate holder or the recipient.

Similar to how a digital signature certificate functions as a digital proof one can present electronically, a certificate works as proof of identity of an individual for a certain purpose. Authorized users can use a DSC to access particular data or services on the internet as well as to prove their identity and digitally sign documents.


1. Where can I buy Digital Signature Certificate?

Only a Controller of Issuers of Digital Signature Certificates can issue legally valid Governmental Certifying Authorities (CCA). licenced by the government of India, certifying Authorities (CA), including Safescrypt, eMudhra, etc. a certifying body (CA) delivers safe digital signatures through a variety of alternatives designed to satisfy both personal and corporate needs.

2. Why do I need a Digital Signature Certificate?

An electronic identity authentication tool is a digital signature certificate. As well enables you to transact online with a high level of security by assuring full confidentiality of the data communicated when a digital signature certificate is used. Using certificates, you can encrypt data so that only the intended receiver can read it. able to read it. Information can be digitally signed to ensure that it has not been altered. Verify your identification as the message’s sender and that nothing has been altered while in transit.

3. Is it possible to utilise one digital signature certificate for several email addresses?

The answer is no. There can only be one email address on a certificate for a digital signature.

4. What is the DSC's validity period?

A DSC having a validity of one or two years may be issued by the Certifying Authorities.

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