What is a certificate authority?

A certificate authority (CA) is a trusted third party that issues digital certificates. These certificates are used to verify the identity of a website or other entity, and to encrypt data sent between them.

List of Certificate Authorities (CAs) with brief information:

1. Let’s Encrypt: Let’s Encrypt is a non-profit organization that provides free SSL/TLS certificates. It is the most popular CA, and it is used by millions of websites.
2. DigiCert: DigiCert is a publicly traded company that provides SSL/TLS certificates, as well as other security products and services. It is a well-respected CA, and it is used by many large enterprises.
3. Comodo: Comodo is another publicly traded company that provides SSL/TLS certificates. It is a popular choice for small and medium-sized businesses.
4. GoDaddy: GoDaddy is a well-known provider of domain names and web hosting services. It also provides SSL/TLS certificates.
5. Sectigo: Sectigo is a privately held company that provides SSL/TLS certificates. It is a popular choice for businesses that need high-level security.
6. Entrust Datacard: Entrust Datacard is a publicly traded company that provides SSL/TLS certificates, as well as other security products and services. It is a well-respected CA, and it is used by many government agencies and financial institutions.
7. IdenTrust: IdenTrust is a non-profit organization that provides SSL/TLS certificates. It is a popular choice for businesses that need to comply with specific regulatory requirements.
8. SSL.com: SSL.com is a privately held company that provides SSL/TLS certificates. It is a popular choice for businesses that need to manage their own certificates.
9. RapidSSL: RapidSSL is a subsidiary of GeoTrust, a publicly traded company that provides SSL/TLS certificates. It is a popular choice for businesses that need affordable certificates.
10. QuoVadis: QuoVadis is a privately held company that provides SSL/TLS certificates, as well as other security products and services. It is a popular choice for businesses that need to comply with EU privacy regulations.

Additional information:

• Certificate authorities are responsible for a number of important tasks, including:
  • Validating the identity of the entity requesting a certificate: This can be done by verifying the entity’s legal name, address, and other contact information.
  • Generating a digital signature: The CA uses its own private key to sign the certificate, which binds the certificate to the entity’s public key.
  • Publishing the certificate: The CA publishes the certificate in a directory that can be accessed by web browsers and other applications.
• Certificate authorities play a crucial role in protecting online communications. When you visit a website that has an SSL certificate, you can be confident that your data is being encrypted and that the website is who it says it is.