An OTP-verified e-signature on a loan agreement, a click-to-accept checkbox on a terms-of-service page, and an Aadhaar-based eSign on a property document all get called "electronic signatures" in everyday conversation — yet Indian law treats some of them very differently from others the moment a dispute reaches court. Section 66 of the Bharatiya Sakshya Adhiniyam, 2023 (BSA) draws the line that decides which electronic signatures the proponent must actively prove, and which ones the law is willing to presume are genuine unless challenged.
66. Proof as to electronic signature. Except in the case of a secure electronic signature, if the electronic signature of any subscriber is alleged to have been affixed to an electronic record, the fact that such electronic signature is the electronic signature of the subscriber must be proved.
Section 66 carries forward Section 67A of the Indian Evidence Act, 1872 — itself a 2000-era insertion by the Information Technology Act — without any change in wording. Its scope is broader than it might first appear: "electronic signature" here is the technology-neutral category recognised under Section 3A of the IT Act, covering everything from Aadhaar-based OTP or biometric authentication to click-wrap consent mechanisms, and standing distinct from the narrower, cryptographically-specific "digital signature" governed instead by Section 73 of this Act, which deals only with the asymmetric-cryptosystem method built around Digital Signature Certificates.
The word doing the real work in Section 66 is "except." The section carves out a specific category — the secure electronic signature — and exempts it from the ordinary proof burden the rest of the section imposes. For a secure electronic signature, the law does not require the proponent to affirmatively prove the signature belongs to the alleged subscriber; a separate presumption provision elsewhere in this Act does that work instead, presuming a secure electronic signature genuine unless the other side proves otherwise. For every electronic signature that does not qualify as "secure" in the technical sense the IT Act defines, Section 66 imposes the ordinary burden: the party relying on the signature must affirmatively prove it is genuinely the subscriber's own.
| Type | Governing rule | Who must prove what |
|---|---|---|
| Secure electronic signature | Presumption of genuineness (Section 86 BSA) | Presumed genuine — challenger bears the burden of disproving it |
| Ordinary (non-secure) electronic signature | Section 66 BSA | Proponent must affirmatively prove the signature is the subscriber's own |
Why does the law treat these two categories so differently? A "secure" electronic signature, under the IT Act's own framework, is one applied through a security procedure agreed between the parties or prescribed by the Central Government — a procedure specifically designed to make the signature uniquely linked to the signatory and detect any subsequent alteration to the signed record. Because that heightened technical reliability is built into the process itself, the law is willing to extend the benefit of the doubt to signatures produced that way, shifting the burden onto whoever wants to dispute them. An ordinary electronic signature — a scanned image of a signature pasted into a document, or a simple checkbox click with no comparable security architecture behind it — carries no equivalent built-in guarantee, so the ordinary evidentiary default applies: whoever relies on it must prove it.
Proving an ordinary electronic signature under Section 66 typically involves establishing the chain of custody and authentication events surrounding the signing — server logs showing the subscriber's login credentials were used, metadata confirming the time and IP address of the signing event, or testimony from the platform operator explaining how the signature was captured and linked to that specific subscriber. None of this is inherently harder to prove than a handwritten signature; it simply requires different kinds of evidence, drawn from the electronic record's own audit trail rather than from ink-on-paper comparison.
It is also worth noting what Section 66 does not do: it does not itself define what makes an electronic signature "secure," nor does it prescribe the specific security procedures that qualify. Those definitions live in the Information Technology Act and its subordinate rules, which the Central Government has the power to prescribe and update as authentication technology evolves. Section 66's role is narrower and more stable — it simply states the evidentiary consequence that follows once a signature is, or is not, classified as secure under that separate framework, leaving the technical classification itself to keep pace with changing technology without requiring this evidence provision to be rewritten every time a new authentication method is recognised.
Key Takeaways
- Unchanged from IEA 67A: Section 66 carries the 2000-era rule forward without any drafting change.
- Broader than "digital signature": this section covers the full technology-neutral category of electronic signatures under IT Act Section 3A, distinct from Section 73's narrower DSC-based digital signature route.
- The secure/non-secure line is decisive: secure electronic signatures benefit from a separate presumption of genuineness (Section 86 BSA); ordinary ones must be affirmatively proved under this section.
- "Secure" is a technical, provable status, not an assumption: a party relying on the presumption should be ready to show the actual security procedure followed.
- Proof draws on the electronic audit trail: login logs, timestamps, and platform authentication records typically do the work handwriting comparison does for ink signatures.
Section 66 is a quiet gatekeeper for an enormous and growing share of everyday transactions — loan agreements, employment contracts, consent forms — that never touch paper at all. Knowing which side of the secure/non-secure line a given electronic signature falls on, before a dispute arises, is what determines whether a party walks into court with a presumption already working in their favour or a proof burden still to discharge.