The first European country to legalize electronic signatures was Germany. 2001February 16, Germany passed a bill, which made electronic signature and handwritten signature have the same legal effect, and Germany became the first European country to legalize electronic signature. Electronic signature is an electronic code. In 2005, the Electronic Signature Law was promulgated and implemented. Electronic signature refers to any electronic technical means that can prove the identity of the parties and approve the contents of documents in electronic communication, which can be called electronic signature. An electronic signature is not a digital image of a written signature. It is actually an electronic code, through which the recipient can easily verify the identity and signature of the sender on the Internet. It can also verify whether the original text of the file has changed during transmission. If someone wants to send an important document to people in other places through the Internet, both the recipient and the sender need to apply for an electronic license from the licensing authority CA(GlobalSign). This encryption certificate includes the applicant's public key on the Internet, that is, the "public computer password", which is used for file verification.