Effective January 1, 2017, Bill 2296 goes into effect regarding electronic signatures. The bill clarifies that a digital signature may be used to satisfy electronic signature requirements as stated in the Uniform Electronic Transactions Act.
http://www.leginfo.ca.gov/pub/15-16/bill/asm/ab_2251-2300/ab_2296_bill_20160819_chaptered.html
California – Digital Signatures