What is Class 3 Digital Signature Certificate ?
Class 3 Digital Signature Certificate (DSC) provides the highest level of assurance or trust within the RCAI hierarchy setup of Controller of Certifying ( CCA ) In India. Class 3 Digital Signature is used to do various transactions like ITR eFiling, ROC, MCA21 eFiling, GST and IEC Registration, Trademark eFiling, eTendering etc.
 
What are the types of Class 3 Digital Signature Certificate ?
Class 3 Digital Signature can be categorized in two types, first one is signing and second is encryption. If both required it will be called as Class 3 Combo DSC.
 
What is Class 3 Individual User DSC ?
Class 3 Individual User DSC can be issued to any individual person. Any Indian residence with valid identit, address proof can buy class 3 individual user dsc. It can be issued for 1, 2 and 3 Years. Currently, Only Class 3 DSC for 2 Years is available. It comes in password protected USB Tokens like ePass Auto 2003 or HYP2003. 
 
What is Class 3 Organization User DSC ?
Class 3 Organization User DSC can be issued to any subscriber who is authorised signatory of organization or if authorised on behalf of that organization. Proprietorship Firm, Partnership Firm, Private Limited, Limited, LLP, Government Organizations, NGO, BPO in India can buy Class 3 Organization DSC. It can be issued also for 1, 2 Year and 3 Years. Currently, Only Class 3 DSC for 2 Years is available. It comes in password protected USB Tokens like HYP2003 to keep it secure. 
 
What is difference in Signing and Encryption Cerrificate in DSC ?
Signing Certificate is used to sign any information or documents online while encryption certificate convert that documents or information into special codes to keep it more secure. In India, Class 3 Signing Certificate is mainly useful for basic signing transactions like ITR eFiling, ROC and MCA eFiling, Trademark registration and Class 3 Signing and Encryption is useful for highly sensitive transactions like etendering, eprocurement etc. 
 
What is USB Token and Why it is required for DSC ?
USB Token is a password protected hardware device for storage of digital signature certificate in India. It is approved by CCA and comes with FIPS Certification. It is mandatory to download digital signature in USB Token. You can use this USB Token on your computer while using it.
Class 3 Digital Signture - Signing DSC Uses:- 
Income Tax Return ( ITR ) eFiling, Audit eFiling
ROC and MCA eFiling
GST Registration
IEC Registration
Trademark and Patent eFiling
IRCTC eTicketing
Directors EKYC
Provident Fund, EPFO
Traces
ICEGate, eSanchit, MEIS, SEIS Website. ( Class 3 Individual User Combo Required )
Company Registration
Class 3 Organization User - Combo DSC Uses
All India eProcurement Websites
All Indian eBidding, eAuction Websites
Gram Panchayat, Gram Sachiv, Gram Pradhan, 
Gram Sarpanch, CERSAI Website
AICTE and CBSE Affiliated Institutions