A Digital Signature Certificate, or DSC, is the electronic credential that proves who signed a document and that the contents have not changed. In India the system runs under the Information Technology Act, 2000, and the certificate you almost always need today is Class 3. This guide explains the current DSC types, who issues them, and what each one lets you do.
Key Takeaways
- A DSC binds your identity to a public key and follows the X.509 standard (NIST).
- Class 2 DSC issuance ended on January 1, 2021; Class 3 is now the standard for income-tax, MCA, GST, and e-tender filings (ClearTax).
- DSCs come as Signing, Encryption, or combined certificates, are valid for one to three years, and live on a secure USB token.
What is a Digital Signature Certificate (DSC)?
A Digital Signature Certificate binds your identity to a public key and is issued by a trusted Certificate Authority, using the standard X.509 format (NIST CSRC). In India it is the legal instrument that lets you sign filings online so government portals can verify you. Think of it as a tamper-evident digital ID card.
The certificate carries your name, your public key, the issuing authority, and a validity window. When you sign a document, the matching private key on your token produces a signature that anyone can check against the certificate. If a single byte of the file changes after signing, verification fails. That is how a DSC proves both identity and integrity.
For a fuller breakdown of how the certificate and the signature differ, see our guide on digital certificates versus digital signatures.
Which classes of DSC exist today, and why is Class 3 the standard?
Class 3 is the standard DSC in India. Class 2 issuance was discontinued effective January 1, 2021, following a CCA directive dated November 26, 2020, and Certifying Authorities now issue Class 3 in its place (ClearTax). Class 3 serves the combined Class 2 and Class 3 role across statutory and high-assurance filings.
This is the part many older articles get wrong, so it is worth stating plainly. There is no current Class 2 certificate to buy. Existing Class 2 certificates stayed valid until their expiry date, but they cannot be renewed, and any new application is fulfilled as Class 3.
Where does Class 1 fit?
Class 1 still exists, but it is a low-assurance certificate that confirms an email address and name only. It is not used for company filings, tax returns, or tenders. If you are signing anything statutory in India, Class 1 is not the certificate you want.
So the practical landscape is simple. For business and compliance work you use Class 3, the single standard certificate that handles income-tax filing, MCA and ROC submissions, GST, e-tenders, and audit reports.
Signing, Encryption, or combined: which certificate type do you need?
Beyond classes, a DSC is issued by function. The three options are a Signing certificate, an Encryption certificate, or a combined certificate that carries both. Most business buyers order the combined type because filings sometimes need confidential transmission as well as a verifiable signature on the same token.
The difference comes down to the job each one does:
| Certificate type | What it does | Typical use |
|---|---|---|
| Signing | Authenticates the signer and proves the document was not altered | E-filing, signing returns and forms |
| Encryption | Encrypts the document so only the intended recipient can read it | Confidential tenders, sensitive data exchange |
| Signing + Encryption | Both functions on a single certificate | Most business and e-tender workflows |
If you only ever sign and never need to encrypt, a Signing certificate is enough. When a portal or tender process asks for an Encryption certificate, that is a separate function, not a higher class. To see how DSCs compare with simpler signing methods, read our overview of electronic signature types and examples.
Who issues a DSC in India?
In India, Digital Signature Certificates are issued by Certifying Authorities (CAs) that are licensed by the Controller of Certifying Authorities (CCA), a body established under the Information Technology Act, 2000 (CCA). You buy your DSC from one of these licensed CAs, not from the government directly.
The trust runs in a hierarchy. The Root Certifying Authority of India (RCAI), operated by the CCA, anchors the chain. RCAI signs the licensed CAs, and the CAs in turn issue your DSC. When a portal verifies your certificate, it walks this chain back to RCAI to confirm the certificate is genuine and was issued by an authority the government trusts.
That chain is why a DSC carries legal weight that a scanned signature image never can. The legal backing for all of this sits in the IT Act, which we cover in our explainer on e-signature laws in India.
What can you do with a DSC?
A Class 3 DSC unlocks the main statutory filing portals in India. It is accepted for income-tax e-filing, Ministry of Corporate Affairs and ROC submissions, GST, e-tenders, and audit reports, which is why it replaced Class 2 as the single standard (ClearTax). One certificate covers most compliance obligations a business faces.
Some processes are specific about the class they accept. For Import-Export Code (IEC) work, the Directorate General of Foreign Trade (DGFT) accepts only Class 3 DSC. So an exporter applying for or amending an IEC must hold a current Class 3 certificate; nothing lower will pass.
In day-to-day terms, a DSC lets a director approve company forms, an accountant file returns, and a bidder submit a sealed e-tender, all without printing or couriering paper. Once the certificate is on your token, signing is a matter of plugging it in and entering your PIN.
How long is a DSC valid, and how do you get one?
A DSC is typically valid for one to three years and is stored on a secure USB token, also called a crypto token, which holds the private key in hardware (CCA). Keeping the key on the token, rather than on a hard drive, is what makes the certificate hard to copy or steal.
Getting one follows a short path. You pick a licensed Certifying Authority, choose Class 3 and the certificate type you need (Signing, Encryption, or combined), and complete identity verification, often through Aadhaar or PAN-based KYC. The CA then issues the certificate, which you download onto the token.
When the certificate reaches its expiry date, you apply for a fresh one rather than renewing an old Class 2 cert. Once your DSC is active, you can pair it with an online signing workflow such as Document eSign's electronic signature platform to route, sign, and store documents end to end.
Frequently asked questions
Is there still a Class 2 DSC in India?
No. Class 2 DSC issuance was discontinued from January 1, 2021, following a CCA directive dated November 26, 2020 (ClearTax). Certifying Authorities now issue only Class 3 DSC, which covers the work Class 2 used to handle plus higher-assurance uses.
Which DSC class do I need for income-tax and MCA filings?
Class 3 DSC is the certificate used for income-tax e-filing, MCA and ROC filings, GST, e-tenders, and audit reports. Since Class 2 was retired in 2021, Class 3 is the single standard for these statutory submissions in India.
What is the difference between a Signing and an Encryption certificate?
A Signing certificate authenticates the signer and protects document integrity. An Encryption certificate keeps the document confidential by encrypting its contents. Many DSC orders bundle both as a combined Signing plus Encryption certificate on one token.
How long is a DSC valid?
A DSC is typically valid for one to three years and is stored on a secure USB crypto token. When it expires you apply for a fresh certificate from a licensed Certifying Authority. Old Class 2 certificates stayed valid until expiry but cannot be renewed.