Identity authentication method. Digital signature is one of the core technologies to achieve online transaction security. It can ensure the confidentiality of information transmission, the integrity of data exchange, the non-repudiation of sent information and the certainty of the identity of the trader. It is mainly used as a method to ensure identity authentication. When signing a group digital signature, in order to show humility, do not grab the first place, and the handwriting should not be too large, leaving more space for everyone.