1. Article 2 of the Law on Electronic Signatures stipulates that the term "electronic signature" as mentioned in this Law refers to the data contained in the data message in electronic form, and attached with data for identifying the identity of the signer and indicating that the signer approves its contents. It can be seen that the essence of electronic signature is data. The electronic seal we see is only an image form of electronic signature, and the data behind it is the electronic signature. From a technical point of view, the technical means to realize electronic signature include password, password or personal identification PIN, bank U shield, digital signature based on public key cryptography, biometric (fingerprint, voice, iris) extraction data and so on.