What is Digital Signature Certificate(DSC) ?

bharath (student) (45 Points)

02 September 2010  



Digital Certificates serve as your identity in the digital world. Just as a passport or a driver's license is used to uniquely identify individuals in the physical world, digital certificates are used to identify entities in digital transactions. Based on Public Key Cryptography, these Digital Certificates associate every entity with a unique pair of credentials - the public key and the private key. Only the owner of a Digital Certificate has access to the private key and can use it to digitally sign and encrypt any digital information such as emails, forms, files etc.


A Digital Signature Certificate, like hand written signature, establishes the identity of the sender filing the documents through internet which sender cannot revoke or deny. Accordingly, Digital Signature Certificate is a digital equivalent of a hand written signature which has an extra data attached electronically to any message or a document. Digital Signature also ensures that no alterations are made to the data once the document has been digitally signed. A DSC is normally valid for 1 or 2 years, after which it can be renewed.


The IT Act has given legal recognition to digital signature meaning, thereby, that legally it has the same value as handwritten or signed signatures affixed to a document for its verification.


The Information Technology Act, 2000 provides the required legal sanctity to the digital signatures based on asymmetric cryptosystems. The digital signatures are now accepted at par with handwritten signatures and the electronic documents that have been digitally signed are treated at par with paper documents. 


Under MCA21 Every person who is required to sign manual documents and returns filed with ROC is required to obtain a Digital Signature Certificate (DSC). Accordingly following have to obtain Digital Signature Certificate: 

 1. Directors 

 2. Auditors

 3. Company Secretary - Whether in practice or in job. 

 4. Bank Officials - for Registration and Satisfaction of Charges 

 5. Other Authorized Signatories.



 WHAT IS e-token ?


A Digital Signature certificate (DSC) is kept in internet explorer of computer system (PC) but keeping DSC on your computer system has following draw backs :-

     a) It can be misused by anyone who is having access to your computer system

     b) DSC is lost if computer system is formatted or internet explorer is changed. 

Accordingly, safe and proper method is to keep DSC on e-token, a small USB port devise, which is password protected. The said e-token is a small hardware device and can be plugged to USB port of any system to digitally sign the documents and when not in use can be kept in safe custody.




There are 3 types of Digital Signature Certificates, having different security levels, namely :-  Class-1, Class-2 , Class-3.

For filing documents under 
MCA21, a  Class-2 Digital Signature Certificate issued by a Licensed Registration Authority is required.

Class – 1 Certificate:

Digitally sign email - You can digitally sign your email messages using Personal Digital Certificate so that the recipient is assured that the email has come from you.

Encrypt email - You can encrypt emails using Personal Digital Certificate to prevent unauthorized people from reading it.

Authenticate to Web Servers - You can authenticate yourself to a Web Server to engage in secure communication with Web Server using Personal Digital Certificate. This protects all information such as credit card details that you send to the Web Server.

Class-1 Certificates however, do not facilitate strong authentication of the identity of the Subscriber; hence are not intended for, and shall not be relied upon, for commercial use where proof of identity is required


Class – 2 Certificate:

Class-2 Certificates are issued as Managed Digital Certificates to employees/ partners/ affiliates/ customers of business and government organizations that are ready to assume the responsibility of verifying the accuracy of the information submitted by their employees/ partners/ affiliates/ customers.

 This organization requests the issue of Digital Certificates for employees/ partners/ affiliates/ customers of the organization. In the case of a Class-2 Certificate, the verification of details supplied with the request for a Digital Certificate is done by these organizations

Class – 3 Certificate:

Class-3 Certificates are issued to individuals, companies and government organizations. They can be used both for personal and commercial purposes. They are typically used for electronic commerce applications such as electronic banking, electronic data interchange (EDI), and membership-based on-line services, where security is a major concern. Class-3 Certificates issued are legally valid under the Indian IT Act 2000.


MCA21 eFiling 

DGS&D e-Tendering

Directorate of Commercial  Taxes - West Bengal

 Patent/Trademark e-Filing

IRCTC e-Ticketing

Northern Railway eProcurement


Certifying Authorities (CA) has been granted a license to issue a digital signature certificate under Section 24 of the Indian IT-Act 2000. One can procure Class 2 or 3 certificates from any of the certifying authorities. 

Tata Consultancy Services (TCS)

National Informatics Center (NIC)

IDRBT Certifying Authority

SafeScrypt CA Services, Sify Communications Ltd.

(n) Code Solutions CA

MTNL Trust Line

*Customs & Central Excise


*The MCA21 application testing and integration with iCERT issued DSCs is currently in progress.

Cost of DSC for 1 year validity would be around Rs.150- Rs.2000 (Depending on the Certifying Authorities)