What Is an SSL Certificate?
SSL, which stands for Secure Sockets Layer, is a popular Digital Certificate. At the heart of every SSL certificate, you will find a set of cryptographic keys. These keys are different on each certificate and they uniquely represent the organization or person for whom the certificate is issued.
What Is the Purpose of an SSL Certificate?
The cryptographic keys in SSL certificates are commonly used to enable HTTPS on websites. Additionally, SSL certificates can confirm the identity of the domain where they are installed, thus preventing phishing attacks. SSL certificates have other uses as well, such as verifying that programs and documents have not been tampered with.
How Do SSL Certificates Work?
Each certificate is created by a trusted Certificate Authority. Before issuing the SSL, the Certificate Authority has the task of verifying the data submitted by the applicant. Once all data is confirmed to be correct and factual, a set of cryptographic keys is generated and the certificate is issued.
An SSL certificate’s security value is derived from two main factors: that the Certificate Authority that has issued the SSL is a trusted one and that the Certificate Authority has performed validity checks before issuing the certificate. As such, when you purchase an SSL certificate and install the SSL on your website, the Certificate Authority effectively vouches for the authenticity of your website.
Each Certificate Authority has its own certificate known as a Root CA certificate. This Root CA certificate is used during the creation of your SSL certificate. The Root CA certificates are trusted by most operating systems and web browsers and as such, your SSL certificate is also trusted by extension.
It is actually not common for a Certificate Authority to use its Root CA certificate to issue SSL and other end-user certificates. Instead, an additional layer of certificates is used. These additional certificates are called Intermediate Certificate Authority (CA) certificates.
What Is the Purpose of the Intermediate CA Certificate?
Intermediate CA certificates act as middlemen between the Root CA certificate and the certificates issued to end-users. All three types of certificates create a chain of trust: the web browser implicitly trusts the Root CA certificate, the Root CA certificate trusts the Intermediate CA certificate, and finally, the Intermediate CA certificate trusts the end-user’s SSL certificate.