SSL certificates can be divided into single domain name certificates, multi-domain name certificates and wildcard certificates according to the number and types of domain names supported.
1) Single domain name SSL certificate: Literally, it is an ordinary SSL certificate that only protects one domain name, which can be a top-level domain name or a second-level domain name.
2) Multi-domain SSL certificate: Literally, it means that multiple domain names can be protected at the same time, whether it is the main domain name or the sub-domain name. Generally, 2~250 domain names can be protected. When you have a new domain name to protect, you can add it at any time. If the number exceeds the protection, you need to pay a certain additional fee, but it is much more cost-effective than re-applying for SSL certificates and saves the time for re-examination.
3) Wildcard SSL certificate: it can protect a domain name and all its subordinate domain names, and it is limited in scope and unlimited in quantity. Suitable for users with a large number of second-level domain names.
According to the authentication methods, SSL certificates can be divided into DV certificates (domain name authentication type), OV certificates (enterprise authentication type) and EV certificates (extended authentication type).
1)DV SSL certificate: it is also a domain name verification certificate. When applying for this certificate, CA only needs to check the ownership of the domain name. The whole process is very simple, and it is completed automatically by the system without manual work. Therefore, the time is relatively fast, and it can be sent out in about 10 minutes, and the price is relatively cheap and the level is relatively low, which is suitable for personal websites and websites of small institutions or enterprises.
2)OV SSL certificate: This is an enterprise verification type, which is higher than the verification requirements of DV certificate. It not only needs to verify the ownership of domain names, but also needs to verify the identity of enterprises. If it is verified, it is necessary to provide information such as enterprise information and scanned copies of company business licenses, all of which are manual audits. It usually takes 3-5 working days to send it, and the price is relatively high, but the security level is greatly improved, which is suitable for websites of general institutions or small and medium-sized enterprises.
3)EV SSL certificate: This is the most secure certificate in the industry at present, and its function is more powerful than the first two. If the user installs this certificate, the browser will not only display the green address bar and https prefix, the sign of security lock, but also display the company name, which not only looks tall, but also is really safer. Of course, the EV SSL certificate audit is also the most stringent, and it is necessary to provide information such as enterprise information, scanned copies of company business licenses, and letters of opinions from Deng Bai or lawyers. CA agencies will manually verify the agency and telephone information, which generally takes 3-7 working days to issue, and the price is relatively high. Suitable for online trading websites, large enterprises or financial banking institutions.