EFFECT OF DIGITAL SIGNATURES
19. The portion of an electronic record that is signed with a digital signature shall be treated as a secure electronic record if the digital signature is a secure electronic signature by virtue of section 20.
20. When any portion of an electronic record is signed with a digital signature, the digital signature shall be treated as a secure electronic signature with respect to such portion of the record, if —
the digital signature was created during the operational period of a valid certificate and is verified by reference to the public key listed in such certificate; and
the certificate is considered trustworthy, in that it is an accurate binding of a public key to a person’s identity because —
the certificate was issued by a licensed certification authority operating in compliance with the regulations made under section 42 ;
the certificate was issued by a certification authority outside Singapore recognised for this purpose by the Controller pursuant to regulations made under section 43;
the certificate was issued by a department or ministry of the Government, an organ of State or a statutory corporation approved by the Minister to act as a certification authority on such conditions as he may by regulations impose or specify; or
the parties have expressly agreed between themselves (sender and recipient) to use digital signatures as a security procedure, and the digital signature was properly verified by reference to the sender’s public key.
21. It shall be presumed, unless evidence to the contrary is adduced, that the information (except for information identified as subscriber information which has not been verified) listed in a certificate issued by a licensed certification authority is correct if the certificate was accepted by the subscriber.
22. Unless otherwise provided by law or contract, a person relying on a digitally signed electronic record assumes the risk that the digital signature is invalid as a signature or authentication of the signed electronic record, if reliance on the digital signature is not reasonable under the circumstances having regard to the following factors:
facts which the person relying on the digitally signed electronic record knows or has notice of, including all facts listed in the certificate or incorporated in it by reference;
the value or importance of the digitally signed electronic record, if known;
the course of dealing between the person relying on the digitally signed electronic record and the subscriber and any available indicia of reliability or unreliability apart from the digital signature; and
any usage of trade, particularly trade conducted by trustworthy systems or other electronic means.