The Information Technology Act, 2000
§15 — Secure electronic signature
An electronic signature shall be deemed to be a secure electronic signature if– (i) the signature creation data, at the time of affixing signature, was under the exclusive control of signatory and no other person; and (ii) the signature creation data was stored and affixed in such exclusive manner as may be prescribed. Explanation.–In case of digital signature, the “signature creation data” means the private key of the subscriber.