How to use an Aadhaar-based e-signature on your document

August 16, 2025

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How to use an Aadhaar-based e-signature on your document

Digital signatures have been in existence in India since 2000. However, their format made them inaccessible to a majority of the Indian population. The introduction of Aadhaar eSign transformed the landscape of digital signatures. now, individuals can sign documents electronically with a valid aadhaar number and a linked phone or email ID.

Introduction

Aadhaar eSign revolutionized the process of digitally signing documents in India using an Aadhaar card. The use of Aadhaar-based e-signatures on documents carries the same legal and evidentiary weight as handwritten signatures.

Previously, electronic signing in India was limited to USB-token-based digital signatures, also known as digital signature certificate tokens or DSC tokens.

These digital signatures have been in existence in India since 2000. However, their format made them inaccessible to a majority of the Indian population. The introduction of Aadhaar eSign transformed the landscape of digital signatures. Now, individuals can sign documents electronically with a valid Aadhaar number and a linked phone or email ID. The simplicity of using Aadhaar eSign has made it accessible to a wide range of Indians. Despite its user-friendly approach, Aadhaar eSign maintains the security and enforcement advantages of standard digital signatures.

How secure is Aadhaar eSign?

According to section 3a and schedule 2 of the Information Technology Act, using an Aadhaar eSign in India for electronic document signing is both legally valid and highly secure. Aadhaar eSign can be applied to most documents, except for negotiable instruments (excluding cheques), powers-of-attorney, documents involved in establishing trusts, as well as wills and other testamentary depositions.

Why is Aadhaar eSign groundbreaking?

No need for acquisition: There is no need to go through a complicated process of "ordering" or acquiring anything. anyone with an aadhaar number and a linked phone/email can use aadhaar esign.
User-friendly esigning: It is effortless to esign using aadhaar. basic knowledge of using a phone and entering OTP's is all that is required.
No physical device required: Aadhaar esign is a remote and device-less method. as long as individuals have their phones with them, they can esign from anywhere.
Mobile compatibility: Since most indians access the internet through mobile devices, aadhaar esign is well-suited to the digital habits of the general population in india.
Highly scalable for over 1 billion citizens: This approach has immense scalability potential and could potentially revolutionize the execution of paperwork in india.

working of an aadhar esign: explained

Step 1: Signatories access the document, give consent, and click on a signing link provided by an application service provider (ASP) on a user interface. During this stage, the ASP also performs a hashing function on the document to generate its hash result (known as the input document hash).

Step 2: Once the signers click the signing link, they are directed to a portal maintained by the eSign service provider (ESP). Here, the signer enters their Aadhaar number. The ESP requests the Unique Identification Authority of India (UIDAI) to perform an electronic Know Your Customer (eKYC) process with the signer. UIDAI sends a one-time password (OTP) to the signer’s registered mobile number or email address. The signer enters the OTP on the portal. If the OTP is correct, UIDAI verifies the signer’s identity authentication as successful.

Step 3: After successfully authenticating the signer’s identity, the ESP generates a secure key pair for the signer.

Step 4: Once the key pair is generated, the ESP sends the signer’s public key and the eKYC information (received from UIDAI) to the certifying authority (CA) following the format specified by the controller of certifying authorities (CCA) under the eSign application programming interface (API) specifications. Upon receiving these details, the CA issues the electronic signature certificate for the signer and forwards it to the ESP.

Step 5: The ESP encrypts the input document hash (provided by the ASP in step 1) using the signer’s private key to create an encrypted hash result. Subsequently, the ESP transfers the electronic signature certificate and the encrypted hash result to the ASP, which facilitates the placement of the e-sign onto the document.

And with that, the Aadhaar eSign process is successfully completed.

how esign has been made safe and secured?

In order to ensure the safety and reliability of e-sign services, certain measures are implemented. First and foremost, authentication is carried out using Aadhaar eKYC services, which require individuals to verify their identity.

Once an individual’s identity is successfully authenticated through methods such as biometric or OTP verification, eSign facilitates the generation of key pairs, certification of the public key, and the application of a digital signature on the electronic document. All of these processes are seamlessly conducted through a single online service.

The private key pair, used for the digital signature, is employed only once and is then promptly deleted after a one-time use. This practice helps enhance security and prevent unauthorized access.

The digital signature certificate produced through eSign remains valid for a duration of 30 minutes and subsequently expires. This expiration feature is in place to maintain the overall security of the system.

When a document is signed using eSign, it is embedded with a legitimate electronic signature (eSign) that can be easily verified using standard verification methods.

To utilize eSign integration with a PIN, a gateway manages the PIN function, while an ASP (application service provider) can directly integrate with eSign.

It is important to note that in this particular integration, the optional PIN feature will not be available, limiting the authentication options to biometric verification and OTP (one-time password) verification.

conclusion

The use of Aadhaar-based services has witnessed a significant rise since the demonetization in November 2016, making it the world’s most extensive biometric identification system, with 1.3 billion Aadhaar cards generated to date. Traditional document signing processes are often time-consuming, require physical presence, and come with security and logistical challenges. However, the introduction of Aadhaar-based e-signature has revolutionized this process by offering remote access, eliminating paperwork and long queues, and reducing carbon footprint. Businesses can now save valuable resources such as time, capital, and workforce management while operating in an eco-friendly digital environment with high process efficiency. Through curated e-signature tools provided by software companies, organizations, and individuals, they can now efficiently execute legally binding documents using e-sign Aadhaar.