Section 73 of Evidence Act "Comparison of signature, writing or seal with others admitted or proved"
In order to ascertain whether a signature, writing, or seal is that of the person by whom it purports to have been written or made, any signature, writing, or seal admitted or proved to the satisfaction of the Court to have been written or made by that person may be compared with the one which is to be proved, although that signature, writing, or seal has not been produced or proved for any other purpose
The court may direct any person present in Court to write
any words or figures for the purpose of enabling the Court
to compare the words or figures so written with any words or
figures alleged to have been written by such person.
Section 73a of Evidence Act "Proofs as to verification of digital signature"
In order to ascertain whether a digital signature is that
of the person by whom it purports to have been affixed, the
court may direct-
(a) that person or the Controller or the Certifying Authority to produce the Digital Signature Certificate;
(b) any other person to apply the public key listed in the Digital Signature Certificate and verify the digital signature purported to have been affixed by the person.
Explanation.- For the purpose of this section "Controller" means the Controller appointed under sub-section (1) of section 17 of the Information Technology Act, 2000.]