Digital certificates are currently the most mature and widely used information security technology in the world. In layman's terms, a digital certificate is the identity card of an individual or organization on the Internet. Digital certificates are based on cryptography and use technologies such as digital signatures, digital envelopes, and timestamp services to establish an effective trust mechanism on the Internet. It mainly contains the certificate owner's information, the certificate owner's public key and the signature of the certificate authority.

Electronic data preservation actually means using some professional technologies to encrypt and calculate, and incidentally mark some preservation time, number, value, etc., so that the electronic data can maintain its original appearance no matter how long it is saved. No one can easily tamper with it.