California Code, Government Code - GOV § 36932

(a) Ordinances shall be signed by the mayor and attested by the city clerk.  When attesting to an electronic or digital signature, the clerk may presume that the signature is genuine and attributable to the signatory if the electronic or digital signature complies with the requirement set forth in subdivision (a) of Section 16.5.

(b) The amendments made to this section by the act that added this subdivision shall not be construed to affect the validity of a clerk's attestation to any other digital or electronic signature.