Introduction
SSL Certificate (Security Certificate) is a data file that associates a cryptographic key with its owner. SSL Certificates are issued to individuals and organisations for the purpose of identifying themselves or the services they provide.
In the context of webhosting a security certificate is necessary to make your website securely available to visitors using the HTTPS protocol. When using the HTTPS protocol all communication between the server and the client’s web browser is encrypted so that no third party can eavesdrop or tamper with this communication.
The following information is included in the web server security certificate:
- How the communication between the server and the client is encrypted;
- the website for which the certificate is generated;
- who is the owner of the certificate (contact details of the person or company);
- who validates the certificate (certification authority or body).
The abbreviation SSL originally stood for Secure Sockets Layer protocol, which has now been replaced by a much more modern and secure protocol called Transport Layer Security (TLS). However, SSL continues to be used in many places to denote secure connections.
Types of certificates
Certificate authorities issue mainly four types of certificates for servers:
- A certificate associated with a single domain or host name;
- ‘wildcard’ certificate associated with multiple hostnames;
- ‘multi-domain’ certificate associated with multiple domain names;
- aggregate communication aka ‘unified communications’ certificate.
Certification centres
There are many certification authorities around the world, but only a few are recognised and used globally.
The largest CAs are IdenTrust (associated with the Let’s Encrypt initiative), Comodo, DigiCert (owning Thawte, RapidSSL, VeriSign and GeoTrust brands) and GoDaddy.
There is also one certification centre in Estonia, a company called SK ID Solutions which specialises primarily in identity authentication.
Certificate validation
For servers and services, certification centres use three main processes to validate security certificates:
- Domain validation of the domain associated with the certificate;
- standard organisation or individual identity and representation validation (organisation validation);
- broad-based organization or individual identification
Certificate prices
Certificate prices depend on three factors:
- the type of certificate and the technical capabilities;
- trustworthiness of certification body;
- thoroughness of the certificate validation process.
Let’s Encrypt certificates, which validate the authenticity of a single domain or host, are free of charge for the user of the Zone web hosting service and are issued automatically when an HTTPS connection is established.
Related references
How to order an SSL Certificate https://www.zone.ee/en/security/ssl-certificate/