Working Principle of a Digital Signature

Digital Signature is an encrypted signature. It is a cryptographic value that is calculated from the data and a secret key known only by the signer. Digital Signatures could be described as an electronic “fingerprint”. It securely associates the signer to the agreements or documents he signs. To ensure security, the system makes use of an accepted format, known as the Public Key Infrastructure. The scheme adds a trust factor too by making agreements signed via digital signatures non-repudiable and reliable. 

The working principle of a Digital Signature is based on public key - cryptography. Each individual’s sign involves a pair of keys: the public key and the private key. 

The private key is used for encryption and the public key is used for verification. The data is fed to a hash function which would result in the generation of a hash result. This hash result along with the private key are fed to the signature algorithm, which produces the digital signature out of the same. Verification process is done by tracking the hash function back and comparing it with the original hash function. The public key as well as the signature is applied onto the verification algorithm which results in a value which is compared to the hash result obtained by application of the same hash function to the data sent along with the signature to the verifier. If the two functions match, the signature is verified. 

Digital Signature Certificates

Digital Signature Certificate is a certificate issued for validating and verifying the identity of the person who holds it. This is for the purpose of validating encrypted digital signatures. This could be presented electronically to verify the identity of the holder, to access some relevant information or services or for signing certain documents digitally. 

The different types of digital signature certificates are:

Class 1 certificate - Issued to individuals/private subscribers, will confirm that user's name (or alias) and E-mail address form an unambiguous subject within the Certifying Authorities database.

Class 2 certificate - Where a person’s identity is verified against a trusted, pre-verified database. 

Class 3 - Where the person will have to appear in person in front of a Registration Authority and prove his/her identity. 

Aadhaar eKyc - OTP class of certificates are issued for individuals use based on OTP authentication of subscriber through Aadhaar eKyc. These certificates will confirm that the information in Digital Signature certificate provided by the subscriber is same as information retained in the Aadhaar databases pertaining to the subscriber as Aadhaar holder.

Aadhaar biometric class of certificates are issued based on biometric authentication of subscriber through Aadhaar E-KYC service. These certificates will confirm that the information in Digital Signature certificate provided by the subscriber same as information retained in the Aadhaar databases pertaining to the subscriber as Aadhaar holder.

A digital signature could have a validity of one or two years. This system of digital signatures has been adopted by various governmental agencies and now is a mandatory requirement for specified procedures such as, for instance, filing of reports, applications, and forms by companies.

Procedure for Obtaining a Digital Signature

A licensed Controlling Authority issues the Digital Signature. A Certifying Authority is an authority licensed, under Section 24 of the Information Technology Act, 2000, to issue a digital certificate. A list of licensed Controlling Authorities is given on the MCA portal[1]. 

An applicant has to approach the Controlling Authority with the application for the issue of digital certificate, duly filled. It involves the application and the verification of the personal details by the Certifying Authority (CA). The applicant has to file the identity proof as well as the address proof.

All you need to do is log on to the website of a licensed Certifying Authority[2] which issues digital certificates, where you’ll find the Digital Certification section. Here, you need to specify the kind of entity for which you are applying the digital signature i.e., individual or an organisation, and then download the DSC Registration Form which will appear. Here, you need to fill up the relevant details. Once you are done with that, you have to attach the supporting documents to prove your identity and address attested by an attesting officer; ensure the sign and seal of the attesting officer is properly visible. Further, you need to make the payment for the application of the DSC; this can be done via a cheque or demand draft in favour of the Local Registration Authority. Lastly, you need to post the application along with the demand draft to the Local Registration Authority.

It generally takes three to seven days for a Digital Signature Certificate to be issued by the Certifying Authority. Also on fulfilment of terms and conditions DSC is issued by some CA’s on same day based on E-KYC for Aadhaar Holders. 

The Use & Benefits of a Digital Signature Certificate

A digital signature certificate may be brought into use while sending and receiving digitally signed and encrypted emails, carrying out secure web-based transactions, or to identify other participants of web-based transactions. The same as utilities with respect to web based transactions or procedures such as E-Tendering, E-Procurement, E-Filing in corporate affairs, Tax return filing and so on. It also serves as a mode to sign documents digitally, thus playing a huge role in constructively bringing the idea of paperless offices closer to implementation.

Digital Signature Certificates serve as a reliable and convenient mode of identity authentication. Use of this mode, primarily, results in enhanced efficiency owing to the reduced cost and time demands; documents could be signed in very little time without even having to be present physically. Integrity of data is also maintained since the contents of documents which are signed digitally cannot be altered at a later point of time. The digitally signed documents could be assured of the signer’s authenticity.

External Links:

[1] Licensed Controlling Authorities: Ministry of Corporate Affairs

[2] Issue Digital Certificate: Procure Class 2 or Class 3 certificates from certifying authorities