A digital certificate issued by the Certification Authority is an electronic document with the owner's information and the public key. It includes the user's identification, user's public key and the data signed by Certificate Authority using its digital signature. The digital signature is to ensure the information in the certificate is true. User's public key is used for data integrity so that data will not be tampered during transmission. User's digital signature is one method to ensure non-repudiation of the data.

Digital Certificate is used for authentication during data exchange between server and terminal user. It enables mutual trust between the entities in an electronic transaction.

Security on digital information mainly includes the following:
Authentication
Security of data transmission
Confidentiality (Storage and Transaction)
Integrity
Non-repudiation
Through the following means to meet the safety requirement:
Confidentiality – encryption
Integrity – digital signature
Authentication – digital certificate and digital signature
Non-repudiation – digital signature

Most digital certificates available today are based on X.509V3 to enable authentication and security during data transmission. Before transmission, both parties exchange certificates to authenticate each other. The sender then encrypts and signs the data using the keys (encryption key and signature key) in the certificate so that the message is sent to the right recipient and ensures data confidentiality, authenticity, integrity and non-repudiation.

Storage media