Digital certificates include information like an ID card, except it is digital to be transferred quickly. Digital certificates include identifying the certificate holder (individual or organization) to ensure the identity is accurate. Like DigiCert, Certificate Authorities validate the authenticity of those who apply for a digital certificate before they issue the certificate to you.
Digital certificates utilize public-key cryptography. This means public and private key are used to ensure security and privacy. Digital certificates for secure emails start with the sender who uses their recipient’s public key to encrypt their message. Then, the recipient uses their private key to decrypt the message. Digital certificates for software and larger files are also encrypted, but first, they are passed through a hashing algorithm and made into a message digest. The message digest is encrypted with the sender’s private key. A digital signature is produced and then committed to the file.