Digital IDs and Certificates
A digital ID, like your identity card in the physical world, can prove your identity to others on the internet. A digital ID usually contains the owner’s name, a serial number, expiration dates, a copy of the certificate holder’s public key, and the name and digital signature of the organization which issued the certificate. Some digital IDs conform to the International Telecommunications Union’s (the international body that determines communications standards) X.509 specification.
Digital IDs are based on the most popular encryption public-key cryptography. Public-key cryptography uses a pair of keys: a private key and a public key. A private key (digital ID) is usually used to decrypt or to sign PDFs, which is kept by yourself. The public key (certificate) is stored in a certificate along with other identifying information. The certificate is usually distributed to others who need to verify your digital signature or encrypt data to be retrieved by your private key or digital ID.
Your digital ID proves your identity on the internet. Only with your private key can you have access to the data encrypted by others with your public key. Please make sure your digital ID is safely stored.