First of all, you can post an electronic signature, but it needs a professional electronic signature company to achieve it through technology. What is said upstairs is not an electronic signature, but a seal picture, which has no legal effect. The real electronic signature/seal is an online identity authentication system based on international PKI standards. A digital certificate is equivalent to an online ID card. In the form of digital signature, it carries out online effective authentication through the third-party authoritative authentication (CA), which helps each subject to identify the other party's identity and show their own identity, and has the functions of authenticity and non-repudiation. Different from physical ID cards, digital certificates also have the characteristics of security, confidentiality and tamper resistance, which can effectively protect and securely transmit information transmitted by enterprises on the Internet. The leading company of electronic signature is Jinge, and there are many other companies in the good industry now.