How to sign a pdf using Digital Signature Certificate (DSC)?

DSC (Digital Signature Certificate): How to Sign a PDF, its Classes, and Working Mechanism

Digital Signature Certificate! It sounds like a certificate that verifies the authenticity of any signature on a digital platform or the internet. 

Well, that’s correct.

Digital Signature Certificates are issued by the certifying authorities to validate the identity of its holder. However, it is not like only individuals can have their DSC. There are DSCs for organizations as well and those are called organizational DSCs. Most of you already have an idea about what DSCs are but find them difficult to use. So for you, we will be covering the process of using a USB token and have better clarity on DSC, its classes, and significance as well. 

What is Digital Signature Certificate (DSC)?

Digital Signature certificates are the new-age authentication method and alternative for physical signatures. They ensure the authenticity of documents submitted or shared online. Offline forms are signed physically likewise online forms are signed digitally using DSCs. 

In India, the Information Technology Act, 2000 allows the use of DSCs on Government portals. As per the IT Act, 2000 Only Certification Agencies can issue any DSC. The names of all such Certified Authority (CA) are listed on the Government Portal.

Different Classes of DSC

However, there are different classes of DSCs as well based on the information they store of its user. 

Basically, there are 3 different classes of DSC.

1. Class 1 DSC

2. Class 2 DSC

3. Class 3 DSC

  • Class 1 DSC: These are for individuals. It confirms the user’s name and email details.
  • Class 2 DSC: Generally Director and Signatory authorities of a company require this while filing with the Registrar of Companies (ROC). This is the one needed for companies or trusts to file their tax returns.

{Note: However, w.e.f January 1, 2021 Class 2 DSC has been discontinued. Those who possess Class 2 DSC would be upgraded to Class 3 DSC automatically.} 

  • Class 3 DSC: This is the highest and most secure digital signature certificate available in India. It is used by the Directors and authorized signatories of a company for signing documents digitally. Those who wish to take part in bidding or tenders must also have this. Class 3 DSC is mainly used for the following purposes:
    •  e-Tendering
    •  Patent and Trademark e-filing
    •  MCA e-filing
    •  Income Tax e-filing
    •  LLP registration
    •  Customs e-filing
    •  e-Procurement
    •  e-Bidding
    •  e-Auction
    •  GST Application filing

Now, when you know different classes of DSCs, you definitely must be intrigued about their working mechanism.

Well, if you are not then you should be.

How does Digital Signature Work?

To understand the working mechanism of a Digital Signature Certificate, we first need to know a few terms involved in it.

  1. Hash Function: It is a combination of numbers and letters generated using a mathematical algorithm. It also includes details like email, document, picture, and other types of data for generating hash values.
  1. Public key Cryptography: Cryptography is a science used to keep information safe and secret. Public-key cryptography (also known as asymmetric encryption) is a cryptographic method that uses a key pair system. One key, called the public key, encrypts the data. The other key, called the private key, decrypts the data.

When a signer digitally signs a document, a cryptographic hash is generated for the document. That cryptographic hash is then encrypted using the sender’s private key. It is then appended to the document and sent to the recipients along with the sender’s public key. The recipient can decrypt the encrypted hash with the sender’s public key certificate. A cryptographic hash is again generated on the recipient’s end.

Both cryptographic hashes are compared to check their authenticity. If they match, the document hasn’t been tampered with and is considered valid.

How to Sign pdf with Digital Signature Certificate?

Now you have your DSC token with you in USB format but don’t know how to use it. You can leave your worry aside and start using your DSC after this blog. Let’s continue without wasting more time:

  1. Plugin the token into your system and install the driver. The driver for the token generally is in the device or else you can download it online as well.
  2. The next step is downloading the form for signing digitally.

{Remember: You must have Adobe Acrobat installed in your system. If it is not then you can have it online for free.}

  1. Now Open the downloaded document in Adobe Acrobat.
  1. Click on “Tools” then on “Certificate
  1. Select the area for signing the document using the cursor. Then a pop-up will appear asking for your private key.
  1. Provide the key and then select the “Lock Document After Signing” option to ensure no edits can further be made on the same.
  1. You can save the signed pdf and upload it wherever required.

Final Words

Digital Signature Certificates are very useful and often mandatory while filling online forms. It not only authenticates your identity, provides a high level of security in biddings but also ensures no tampering of the document as well.

All in all, if you don’t have your DSC, get it today. And if you have confusion about where to get it, Contact Professional Utilities and have it with you.

Most Frequent Doubts

Q1. Are DSCs mandatory for company registration?

Ans. Yes, MCA (Ministry of Corporate Affairs) has mandated DSCs while registering a company. To be more specific, classes 2 & 3 DSCs are required for these purposes. DSCs are also important for filing Income Tax, GST, and other government forms.

Q2. How to use DSC?

Ans. DSCs are collected in USB token format, which further can be used for digitally signing the document. You can follow the above-mentioned step to learn using a DSC.

Q3. How to use a DSC USB token?

Ans. You have a USB token for your DSC with you. The next thing you should do is install the driver for DSC, generally, it is pre-installed in your USB. Once successfully installed you can start using the DSC following the steps described above.

Q4. Which DSC class is best for me?

Ans. As such we can’t decide which one best suits you. For that purpose, you first need to understand the different classes of DSCs and their significance as well as limitations.

Q5. Is DSC a digital signature or digital identity?

Ans. It will fall under the digital identity category. People often mistakenly take electronic signatures similar to digital signature certificates. In reality, DSCs working is based on algorithms and a unique identity whereas electronic signatures can easily be manipulated and cannot be a secure source for authentication.