Certificate authority definition
A certificate authority (CA) is a trusted organization that issues digital certificates to verify the identity of websites, organizations, or individuals. These certificates allow two parties (for example, a website and its visitor) to communicate over a secure, encrypted tunnel. Typically, CAs issue SSL/TLS certificates, but they may also issue other types.
CAs play a key role in keeping online communication safe and ensuring users can trust the websites they visit. Some popular CA companies you may have heard of are DigiCert, Let's Encrypt and GoDaddy.
See also: multi-domain SSL
How do certificate authorities work?
- 1.A website or organization asks a CA for a digital certificate. They provide information like their domain name and other key details (like the organization’s legal name).
- 2.The CA checks if the applicant is legitimate. For example, they confirm the organization owns the website and matches the provided details.
- 3.Once everything checks out, the CA creates and issues a digital certificate. This certificate acts as a “proof of trust.”
- 4.The website installs the certificate, allowing it to use HTTPS. This encrypts data exchanged between the website and its visitors.
- 5.Browsers recognize the certificate because they trust the CA, so users can feel safe interacting with the site.
Types of digital certificates
- Code signing certificates. Allow developers to digitally sign software, ensuring users that the download is authentic and hasn’t been tampered with.
- Email signing certificates. Enable secure email communication by allowing users to sign messages, encrypt content, and verify the sender’s identity.
- Object signing certificates. Provide a way to sign and authenticate software objects, confirming their integrity and source.
- User/client certificates. Assist individuals with secure authentication and signature verification.
