DSC vs eSign. Digital Signatures Explained: Differences, Use Cases and Legal Validity of Electronic Signatures in India

A digital signature in India is typically created using either a Digital Signature Certificate (DSC) or an eSign—both legally recognised ways to sign documents electronically and replace physical signatures. At first glance, they seem similar.

Yet they work very differently.

A DSC is created once, issued after identity verification, and can be used repeatedly during its validity period. An eSign, on the other hand, is generated only when a document needs to be signed. Every signing request begins with a fresh identity check.

For professionals, businesses, government agencies, and organisations in India that sign documents regularly or need secure signing for customer-facing or regulated transactions, this difference affects compliance, workflow design, security, and user experience. Understanding how DSCs and eSign work, where each fits, how they compare operationally, and how Indian law treats them makes it much easier to choose the right digital signature method for a particular transaction.

What is a Digital Signature Certificate (DSC) or digital certificate?

DSC stands for Digital Signature Certificate which is a digital identity issued by a licensed Certifying Authority after verifying the identity of the applicant.

It works much like an office access card.

For many professionals, a DSC becomes part of everyday work. Company directors use it while filing documents with the Ministry of Corporate Affairs (MCA). Chartered Accountants use it for tax filings. Company Secretaries rely on it for regulatory filings. Businesses participating in government tenders often require one as well.

Many professionals use DSC in their everyday work. For example:

• Company directors use it while filing documents with the Ministry of Corporate Affairs (MCA).

• Chartered Accountants use it for tax filings. Company Secretaries rely on it for regulatory filings.

• Businesses participating in government tenders often require one as well.

Instead of proving identity every single time, the verification happens only once ie., when the certificate is issued.

How does a DSC work?

Although the technology behind a DSC involves encryption and cryptography, it relies on Public Key Cryptography, which uses a pair of mathematical keys: a public key and a private key.

The digital signature uses a mathematical algorithm embedded in the Digital Signature Certificate, and the signing keys must be kept secure.

The process of using a DSC goes like this:

A process called "hashing" converts the document text into a unique fixed-size string of data called a hash, and even a tiny change creates a different hash value.

1. An application is submitted to a licensed Certifying Authority.

2. Identity documents are verified through the prescribed KYC process.

3. A Digital Signature Certificate is issued.

4. The signing credentials are securely stored, typically in a USB cryptographic token or a secure cloud environment, with private keys protected against unauthorized access.

5. Documents can then be digitally signed whenever required, and if a document is modified after signing, the cryptographic hash changes so the signature no longer verifies.

Because the same certificate is used repeatedly, a DSC usually remains valid for one to three years before it needs to be renewed.

This is why DSCs are commonly used for recurring professional work rather than one-time transactions.

What is an eSign (electronic signature)?

An eSign is a type of digital signature that verifies the signer's identity each time a document is signed. Thus, for an eSign, often Aadhaar OTPs are issued and there is no reusable certificate.

While using an eSign, there is no USB token to carry, long-term certificate to manage, or need to install an application. A fresh digital signature is generated only for that particular document. Once the signing process is complete, the transaction ends.

Because of this, eSign has become popular wherever large numbers of people need to sign documents quickly and conveniently.

For example:

• Banks use it for account opening.

• Fintech companies use it for loan documentation.

• Businesses use it for vendor contracts, customer agreements and consent forms.

How does an eSign work?

Although the experience of using an eSign for verification often feels as simple as entering an OTP, several steps happen in the background, and the user will typically upload a file to the signing platform before authentication.

Users can sign documents online in formats such as PDF and Word documents.

A typical eSign process works like this:

Depending on the platform, a signature may be added by drawing, typing, or using another approved digital-signing method.

1. A document is uploaded or opened for signing on screen.

2. The signer's identity is authenticated through an approved method, such as Aadhaar based authentication.

3. Once the authentication succeeds, a signature type is selected and a digital signature is created for that specific transaction.

4. The signed document is saved and made available to download securely with the digital signature attached.

Each signing request begins with a fresh identity verification.

This makes eSign particularly useful for occasional users and businesses that need to collect signatures from customers, employees or vendors who may never sign another document again.

DSC vs eSign: A Practical Comparison

Both DSC and eSign help create legally recognised digital signatures, but they are designed for different situations. The table below highlights the key differences between DSC and eSign along with a practical and operational comparison.

DSC or eSign: Which is the better option?

There is no universal answer because the right choice depends on the nature of the transaction, the specific document, and the platform or regulator requirements.

A Digital Signature Certificate is the better choice when:

• Documents are signed frequently

• Recurring contract signing is involved and a DSC is required or preferred

• Regulatory or company filings are required

• Government portals specifically require a DSC

For example, a Company Secretary filing MCA forms for multiple clients/businesses benefits from having a reusable certificate rather than completing identity verification every time.

eSign is generally the better choice when:

• Vendor contracts can be completed quickly through eSign

• Employment agreements are issued

• agreements need to be completed quickly

• thousands of people may need to sign the same type of document

For example, an HR team issuing offer letters to hundreds of new employees can save time and avoid printing paper documents by using eSign instead of asking every employee to obtain a DSC.

Understanding Legal Validity of DSC and eSign

A common misconception is that a DSC carries greater legal value because it involves a certificate. But that is not how the law treats them.

A valid DSC created under Section 3 of the Information Technology Act and a valid electronic signature recognised under Section 3A both receive legal recognition under Section 5 of the Act. However, each method has its own legal requirements.

• A DSC must be issued by a licensed Certifying Authority under the framework prescribed by the Controller of Certifying Authorities (CCA). It relies on asymmetric cryptography and a secure hash function, and the subscriber is responsible for keeping the signing credentials under their control. When statutory conditions are met, its legal effect is clear: it can serve as a legally binding signature on electronic documents and create an electronic record.

• An eSign must use a method that satisfies the reliability requirements under Section 3A of the IT Act and is recognised under the applicable legal framework. In simple terms, the signing method must reliably establish the signer's identity, remain under the signer's control at the time of signing, and make any subsequent changes to the signature or document detectable.

Whether a document is accepted ultimately depends not only on these legal requirements being met, but also on whether the relevant law, regulator or digital platform permits that particular method of signing for the transaction.

Legal Implications of DSC vs. eSign

Although both methods are secure, responsibility is handled differently.

With a DSC, the certificate holder is expected to keep the signing credentials secure. During validation, the signed document, digital signature, and public key are checked together. The recipient can verify it by using the sender's public key to recover the original hash and compare it with a newly generated hash; if they do not match, the signature is invalid. If the certificate, token or associated credentials are compromised because they were not adequately protected, disputes may become more complicated.

With eSign, identity is authenticated separately for every signing request. Questions around misuse are therefore more closely connected to the authentication process used for that particular transaction.

Regardless of the method used, organisations should maintain proper records of the signing process. In the event of a dispute, those records often become just as important as the signature itself, and each signed transaction should preserve an automated unalterable log with timestamps and IP addresses; parties can also use Adobe Acrobat Reader to check signed PDFs. Strong security controls such as TLS-encrypted file transfers and ISO/IEC 27001-certified systems help protect signing data.

Digital Signatures Prove Who Signed. Digital Trust Proves What Happened.

Choosing between a DSC and an eSign is rarely about deciding which one is better. It is about selecting the right tool for the right transaction.

As more business moves online, signing a document is only one part of the story. Questions that often arise much later include:

• When was the document signed?

• Was it modified afterwards?

• Who approved it?

• Was consent properly captured?

• Can the entire sequence of events be demonstrated during an audit or legal dispute?

Neither a DSC nor an eSign, by itself, answers every one of these questions. A digital signature helps protect a document by creating a unique, tamper-evident fingerprint, adding enhanced security. That is where digital trust infrastructure becomes increasingly important.

Maintaining reliable evidence, preserving document integrity, recording consent and creating verifiable audit trails are all essential to ensuring that digital transactions remain trustworthy long after the signature has been applied. This fingerprint also helps show whether a document was altered after signing.

Frequently Asked Questions

1. Can a DSC and an eSign both be used to sign PDFs?

Yes. Both can be used to digitally sign PDF documents, and on many platforms they can also be used with Word documents, provided the platform supports the chosen signing method for each file.

2. Can eSign replace a DSC everywhere?

No. Some government portals and regulatory filings specifically require a DSC. In those situations, eSign cannot be used as a substitute.

3. Which option is better for businesses?

It depends on the purpose. Businesses that frequently deal with statutory filings often require a DSC, while eSign is generally more suitable for customer agreements, employee documentation and routine commercial contracts.

4. Which method is more secure DSC or eSign?

Both rely on secure technologies and are recognised under Indian law when used in accordance with the applicable legal framework. The more important consideration is whether the signing process is implemented correctly, how the user's identity is authenticated, whether the signing workflow protects the related data, and whether proper records are maintained.

5. Can digitally signed documents be used as evidence?

A valid digital signature helps establish the authenticity of a document. However, digitally signed electronic records may support proof of a particular person's approval when the applicable legal and evidentiary requirements are met, and admissibility in legal proceedings still depends on the facts of each case.

6. Why are there two different systems if both are digital signatures?

When the Information Technology Act, 2000 was introduced, it recognised Digital Signature Certificates. As technology evolved, the law was amended to recognise other reliable electronic signing methods, including eSign. Today, both are legally valid when they meet the applicable requirements under the Act.

7. What is the main difference between DSC and eSign?

The key difference lies in how they are created and used. A DSC is a reusable digital certificate, while an eSign is generated for each signing transaction, unlike a traditional written signature or handwritten signature placed on paper documents.