{"id":12402254,"date":"2026-05-31T03:19:04","date_gmt":"2026-05-30T19:19:04","guid":{"rendered":"https:\/\/www.likacloud.com\/knowledge\/ssl%e8%af%81%e4%b9%a6%e6%98%af%e4%bb%80%e4%b9%88%ef%bc%9f%e4%bb%8e%e5%85%a5%e9%97%a8%e5%88%b0%e7%b2%be%e9%80%9a%ef%bc%8c%e5%85%a8%e9%9d%a2%e8%a7%a3%e6%9e%90https%e5%ae%89%e5%85%a8%e5%9f%ba%e7%9f%b3\/"},"modified":"2026-05-31T03:28:02","modified_gmt":"2026-05-30T19:28:02","slug":"ssl-certificate-guide-https-security-2026","status":"publish","type":"knowledge_post","link":"https:\/\/www.likacloud.com\/en\/knowledge\/ssl-certificate\/ssl-certificate-guide-https-security-2026\/","title":{"rendered":"What is an SSL certificate? A comprehensive guide from beginner to expert \u2013 understanding the foundation of HTTPS security."},"content":{"rendered":"

In the digital world, every click, every login, and every transaction is protected by an invisible \u201cencryption lock\u201d that safeguards the security of the data. At the heart of this lock lies the SSL certificate. It is not just the small lock icon in the browser\u2019s address bar; it is also the cornerstone of the trust system that underpins the modern internet. Understanding SSL certificates is the first step to comprehending the principles of network security.<\/p>\n\n\n\n

What is an SSL certificate?<\/h2>\n\n\n\n

An SSL certificate, whose full name is Secure Sockets Layer Certificate, has now evolved into its successor, the TLS certificate. However, the industry still commonly refers to it as an SSL certificate. It is a type of digital certificate whose primary function is to establish an encrypted communication channel between the client (such as your browser) and the server (such as the website you are visiting).<\/p>\n\n\n\n

Core working principle: Asymmetric encryption and the handshake process<\/h3>\n\n\n\n

Its working principle is based on asymmetric encryption technology. The server holds two \u201ckeys\u201d: one is the \u201cpublic key\u201d that is made available to everyone, and the other is the \u201cprivate key\u201d that is only known to the server itself. When your browser accesses a website that uses HTTPS, an \u201cSSL handshake\u201d is initiated. The server sends its SSL certificate (which contains the public key) to the browser. After verifying the validity of the certificate, the browser generates a random \u201csession key\u201d and encrypts it using the server\u2019s public key, then sends it back to the server. Only the server, which possesses the corresponding private key, can decrypt this session key. From then on, both parties use this secure session key to encrypt all communication data.<\/p>\n

Recommended Reading What is an SSL certificate? A comprehensive explanation of its principles, types, and deployment configurations.<\/a>\u3002<\/p>\n\n\n\n\n

Key components of a certificate<\/h3>\n\n\n\n

A standard SSL certificate contains several key pieces of information: the domain name or organization to which it is issued; the certificate-issuing authority (CA) that issued it; the validity period of the certificate; and, most importantly, the server\u2019s public key. This information is signed with the CA\u2019s private key to ensure its authenticity and immutability.<\/p>\n\n

\r\n\t\r\n\t\t\r\n\t\r\n\t
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\r\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\"Bluehost\r\n\t\t\t\t\t\t\t\t\t\r\n\t\t\t<\/div>\r\n\t\t\t\r\n\t\t\t\r\n\t\t\t
\r\n\t\t\t\t
\r\n\t\t\t\t\tBluehost SSL Certificate<\/strong>\r\n\t\t\t\t\t\t\t\t\t<\/div>\r\n\t\t\t<\/div>\r\n\t\t<\/div>\r\n\t\t\t\tBlueHost SSL Certificates offer 1-2 year extension options, support for RSA or ECC algorithms, key lengths up to 4096 bits, and up to $1.75 million in protection.<\/span>\r\n\t\t\t\t
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From $7.49 USD per month<\/div>\r\n\t\t\t\t\t\t\t\t\t\t\t\tAccess to Bluehost SSL Certificates \u2192<\/a>\r\n\t\t\t\t\t\t\t<\/div> \r\n\t\t<\/div>\r\n\t<\/div>\r\n\t\t\r\n\t\r\n\t
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\r\n\t\t\t\r\n\t\t\t
\r\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\"hosting.com\r\n\t\t\t\t\t\t\t\t\t\r\n\t\t\t<\/div>\r\n\t\t\t\r\n\t\t\t\r\n\t\t\t
\r\n\t\t\t\t
\r\n\t\t\t\t\thosting.com SSL Certificate<\/strong>\r\n\t\t\t\t\t\t\t\t\t<\/div>\r\n\t\t\t<\/div>\r\n\t\t<\/div>\r\n\t\t\t\tAffordable DV, OV, EV SSL certificates, up to 256-bit encryption, 5 ~ 1 million USD protection amount, 24\/7 support<\/span>\r\n\t\t\t\t
\r\n\t\t\t\r\n\t\t\t\t\t\t\r\n\t\t\t \r\n\t\t\t
\r\n\t\t\t\t\t\t\t\t
From $2.5 USD per month<\/div>\r\n\t\t\t\t\t\t\t\t\t\t\t\tVisit hosting.com SSL Certificates \u2192<\/a>\r\n\t\t\t\t\t\t\t<\/div> \r\n\t\t<\/div>\r\n\t<\/div>\r\n\t\t\r\n<\/div>\r\n\r\n\r\n\n\n\n\n\n\n\n

Why must websites deploy SSL certificates?<\/h2>\n\n\n\n

The deployment of SSL certificates has shifted from being a \u201cbest practice\u201d to a \u201cmandatory requirement,\u201d and its importance is evident on multiple levels.<\/p>\n\n\n\n

Ensure data encryption and privacy.<\/h3>\n\n\n\n

The most basic and important feature is encryption. Without an SSL certificate, all the information you transmit over the internet \u2013 passwords, credit card numbers, chat records, email content \u2013 is transmitted in plain text, making it extremely vulnerable to interception by third parties. SSL encryption ensures that even if the data is intercepted, attackers cannot decipher its contents.<\/p>\n\n\n\n

Implementing authentication and trust mechanisms<\/h3>\n\n\n\n

SSL certificates address the question of \u201cwith whom you are communicating.\u201d Certificates issued by trusted third-party CA (Certification Authorities) verify the identity of the entity that issued them. When you see the lock icon in the browser\u2019s address bar, it indicates that the server you are connecting to actually belongs to the organization specified in the certificate, and not to a fraudulent phishing website.<\/p>\n\n\n\n

Improving search engine rankings and user experience<\/h3>\n\n\n\n

Major search engines such as Google explicitly consider HTTPS as a positive factor in search rankings. Websites without an SSL certificate will have a disadvantage in search results. Furthermore, modern browsers (such as Chrome and Firefox) mark non-HTTPS websites as \u201cinsecure,\u201d which can significantly hinder user access, impact conversion rates, and damage a brand\u2019s reputation. Additionally, HTTPS is a prerequisite for using modern, high-performance networking protocols like HTTP\/2 and QUIC.<\/p>\n

Recommended Reading SSL Certificate Comprehensive Analysis: From Beginner to Expert \u2013 Ensuring the Security of Website Data<\/a>\u3002<\/p>\n\n\n\n\n

The main types of SSL certificates and how to choose them<\/h2>\n\n\n\n

Based on the level of validation and the scope of coverage, SSL certificates are mainly divided into three categories to meet the needs of different scenarios.<\/p>\n\n\n\n

Domain Validation Certificate<\/h3>\n\n\n\n

DV (Domain Validation) certificates are the certificates with the lowest level of validation and the fastest issuance process (usually ranging from a few minutes to a few hours). The Certificate Authority (CA) only verifies the applicant's control over the domain name, for example, by checking specific DNS records or by verifying the receipt of an email. They are suitable for personal websites, blogs, or test environments, providing basic encryption capabilities, but they do not allow the display of organizational information on the certificate.<\/p>\n\n\n\n

Organizational validation type certificate<\/h3>\n\n\n\n

An OV certificate requires a CA (Certificate Authority) to conduct a thorough verification of the authenticity of the applying organization, including checking business registration information and performing phone verifications. The verification process typically takes 1-3 days. The issued certificate will contain information such as the company name. It is suitable for corporate websites, government agencies, and other websites that need to demonstrate a credible identity, thereby fostering greater trust with users.<\/p>\n\n\n

\n\n
\n UltaHost SSL Certificate<\/strong>\n
DV, EV, OV certificates, up to $1,750,000 USD coverage, unlimited sub-domains, iOS and Android apps, discounted 20% per month, $15.95 USD onwards, 30-day money-back guarantee<\/div>\n <\/div>\n\n
\n \n \n \"SSL\n \n \n <\/a>\n \n \n Visit UltaHost <\/a>\n <\/div>\n <\/div>\n\n \n\n\n\n\n\n\n

Extended Validation Certificate<\/h3>\n\n\n\n

EV certificates are the most rigorously verified and highest-trust-level certificates. The review process is extremely stringent and follows globally unified standards. The most distinctive feature is that in browsers that support EV certificates, the company name is displayed in green directly in the address bar. Although the user interface of some browsers has changed in recent years, the highest level of trust represented by EV certificates remains highly favored by the financial, e-commerce, and other high-end industries.<\/p>\n\n\n\n

Classification by coverage scope: Single domain name, multiple domain names, and wildcards<\/h3>\n\n\n\n

In addition to the verification level, the number of domain names covered by the certificate also needs to be considered. A single-domain certificate only protects one specific domain name (for example: www.example.com<\/code>Multi-domain certificates allow you to add hundreds of different domain names to a single certificate. Wildcard certificates, on the other hand, provide protection for a primary domain name and all its subdomains at the same level. *.example.com<\/code> It can protect blog.example.com<\/code>\uff0c shop.example.com<\/code> It is very convenient to manage.<\/p>\n\n\n\n

How to apply for and deploy an SSL certificate?<\/h2>\n\n\n\n

The process of obtaining and installing SSL certificates has become highly standardized and automated.<\/p>\n

Recommended Reading The Ultimate SSL Certificate Guide: From Principles to Deployment \u2013 Ensuring Website Security and Trust<\/a>\u3002<\/p>\n\n\n\n\n

Overview of the Certificate Application Process<\/h3>\n\n\n\n

\u9996\u5148\uff0c\u9700\u8981\u5728\u670d\u52a1\u5668\u6216\u6258\u7ba1\u5e73\u53f0\u4e0a\u751f\u6210\u4e00\u4e2a\u201c\u8bc1\u4e66\u7b7e\u540d\u8bf7\u6c42\u201d\u3002\u8fd9\u4e2aCSR\u6587\u4ef6\u5305\u542b\u4e86\u60a8\u7684\u516c\u94a5\u548c\u7ec4\u7ec7\u4fe1\u606f\u3002\u7136\u540e\uff0c\u5411\u9009\u5b9a\u7684CA\uff08\u5982DigiCert\u3001Sectigo\u3001Let\u2018s Encrypt\u7b49\uff09\u63d0\u4ea4CSR\uff0c\u5e76\u6839\u636e\u6240\u9009\u8bc1\u4e66\u7c7b\u578b\u5b8c\u6210\u76f8\u5e94\u7684\u9a8c\u8bc1\u6d41\u7a0b\uff08DV\u3001OV\u6216EV\uff09\u3002\u9a8c\u8bc1\u901a\u8fc7\u540e\uff0cCA\u4f1a\u7b7e\u53d1\u8bc1\u4e66\u6587\u4ef6\uff08\u901a\u5e38\u5305\u62ec\u516c\u94a5\u8bc1\u4e66\u6587\u4ef6\u548c\u53ef\u80fd\u7684\u4e2d\u95f4\u8bc1\u4e66\u94fe\uff09\u3002<\/p>\n\n\n\n

\u81ea\u52a8\u5316\u4e0e\u514d\u8d39\u8bc1\u4e66\uff1aLet\u2018s Encrypt<\/h3>\n\n\n\n

\u5bf9\u4e8e\u5e7f\u5927\u7f51\u7ad9\u6240\u6709\u8005\u800c\u8a00\uff0cLet\u2018s Encrypt\u7684\u51fa\u73b0\u5177\u6709\u9769\u547d\u6027\u610f\u4e49\u3002\u5b83\u63d0\u4f9b\u5b8c\u5168\u81ea\u52a8\u5316\u7684\u3001\u514d\u8d39\u7684DV\u8bc1\u4e66\uff0c\u6709\u6548\u671f\u4e3a90\u5929\uff0c\u5e76\u901a\u8fc7\u81ea\u52a8\u5316\u811a\u672c\uff08\u5982Certbot\uff09\u53ef\u4ee5\u8f7b\u677e\u5b9e\u73b0\u7eed\u671f\u3002\u8fd9\u6781\u5927\u5730\u63a8\u52a8\u4e86HTTPS\u7684\u666e\u53ca\uff0c\u8ba9\u6bcf\u4e00\u4e2a\u7f51\u7ad9\u90fd\u80fd\u8f7b\u677e\u83b7\u5f97\u57fa\u7840\u7684\u5b89\u5168\u4fdd\u969c\u3002<\/p>\n\n\n\n

Deployment and subsequent maintenance<\/h3>\n\n\n\n

Deploy the certificate file issued by the CA to your web server (such as Nginx, Apache, IIS, etc.) and configure the server to use HTTPS exclusively. After deployment, use online tools to verify that the certificate has been installed correctly and that it contains the complete certificate chain. The key to certificate management is renewal; make sure to renew the certificate before it expires, otherwise, your website will become inaccessible due to the expired certificate. It is recommended to set up expiration alerts or use services that support automatic certificate renewal.<\/p>\n\n\n\n

summarize<\/h2>\n\n\n\n

SSL\u8bc1\u4e66\u8fdc\u975e\u4e00\u4e2a\u7b80\u5355\u7684\u6280\u672f\u914d\u7f6e\u9879\uff0c\u5b83\u662f\u8fde\u63a5\u7528\u6237\u4e0e\u7f51\u7ad9\u4e4b\u95f4\u7684\u4fe1\u4efb\u6865\u6881\u3002\u4ece\u6700\u57fa\u7840\u7684DV\u8bc1\u4e66\u63d0\u4f9b\u52a0\u5bc6\uff0c\u5230OV\/EV\u8bc1\u4e66\u5efa\u7acb\u5f3a\u8eab\u4efd\u8ba4\u8bc1\uff0c\u5b83\u6784\u5efa\u4e86\u5b89\u5168\u3001\u53ef\u4fe1\u7684\u7f51\u7edc\u73af\u5883\u3002\u5728\u5f53\u4eca\u65f6\u4ee3\uff0c\u4e3a\u7f51\u7ad9\u90e8\u7f72SSL\u8bc1\u4e66\u5df2\u662f\u4e00\u9879\u4e0d\u5bb9\u5ffd\u89c6\u7684\u57fa\u7840\u8d23\u4efb\u3002\u65e0\u8bba\u662f\u901a\u8fc7\u514d\u8d39\u3001\u81ea\u52a8\u5316\u7684Let\u2018s Encrypt\uff0c\u8fd8\u662f\u9009\u62e9\u5546\u4e1aCA\u63d0\u4f9b\u7684\u66f4\u9ad8\u7ea7\u522b\u8bc1\u4e66\uff0c\u8fc8\u51fa\u542f\u7528HTTPS\u7684\u8fd9\u4e00\u6b65\uff0c\u5c31\u662f\u5bf9\u7528\u6237\u3001\u5bf9\u81ea\u8eab\u4e1a\u52a1\u5b89\u5168\u6700\u575a\u5b9e\u7684\u627f\u8bfa\u3002<\/p>\n\n\n\n

FAQ Frequently Asked Questions<\/h2>\n\n\n\n

What is the relationship between SSL certificates and HTTPS?<\/h3>\n\n\n\n

SSL\/TLS is a protocol layer that provides encryption and authentication services, while an SSL certificate is the key component for implementing identity verification and key exchange within this protocol. When a website has a valid SSL certificate installed and properly configured, users can securely access the website using the HTTPS (HTTP over SSL\/TLS) protocol. In essence, an SSL certificate is a necessary requirement for enabling HTTPS.<\/p>\n\n\n\n

What is the difference between a free SSL certificate and a paid one?<\/h3>\n\n\n\n

\u4e3b\u8981\u533a\u522b\u5728\u4e8e\u9a8c\u8bc1\u7ea7\u522b\u3001\u529f\u80fd\u3001\u4fdd\u969c\u548c\u670d\u52a1\u3002\u514d\u8d39\u8bc1\u4e66\uff08\u5982Let\u2018s Encrypt\uff09\u901a\u5e38\u662fDV\u8bc1\u4e66\uff0c\u4ec5\u9a8c\u8bc1\u57df\u540d\u6240\u6709\u6743\uff0c\u7b7e\u53d1\u5feb\uff0c\u9002\u5408\u4e2a\u4eba\u6216\u5c0f\u578b\u9879\u76ee\u3002\u4ed8\u8d39\u8bc1\u4e66\u5219\u63d0\u4f9bOV\u3001EV\u7b49\u66f4\u9ad8\u7ea7\u522b\u7684\u9a8c\u8bc1\uff0c\u80fd\u5728\u8bc1\u4e66\u4e2d\u663e\u793a\u4f01\u4e1a\u4fe1\u606f\uff0c\u63d0\u5347\u4fe1\u4efb\u5ea6\u3002\u6b64\u5916\uff0c\u4ed8\u8d39\u8bc1\u4e66\u901a\u5e38\u63d0\u4f9b\u66f4\u957f\u7684\u6709\u6548\u671f\uff08\u59821-2\u5e74\uff09\u3001\u4ef7\u503c\u66f4\u9ad8\u7684\u4fdd\u4fee\u91d1\uff08\u7528\u4e8e\u8d54\u507f\u56e0\u8bc1\u4e66\u95ee\u9898\u5bfc\u81f4\u7684\u635f\u5931\uff09\u3001\u4ee5\u53ca\u4e13\u4e1a\u7684\u6280\u672f\u652f\u6301\u670d\u52a1\u3002<\/p>\n\n\n\n

Is a website absolutely secure once the SSL certificate is installed?<\/h3>\n\n\n\n

Absolutely not. SSL certificates primarily address the issues of \u201cdata transmission security\u201d and \u201cserver identity verification\u201d during communication. They do not prevent vulnerabilities in the website itself, such as SQL injection, cross-site scripting attacks, server breaches, or the use of weak passwords. Website security is a systematic effort that requires a combination of secure coding practices, server hardening, firewalls, and regular patch updates. SSL certificates are just a crucial component of this overall security framework.<\/p>\n\n\n\n

What are the consequences of a certificate expiration?<\/h3>\n\n\n\n

An expired certificate can lead to catastrophic consequences. Browsers and client applications will disconnect from your website and display a prominent \u201cunsafe\u201d warning to users, indicating that the connection is no longer secure. As a result, users will be unable to access the website properly, which can severely impact business operations, brand reputation, and the user experience. Therefore, it is essential to establish a reliable mechanism for monitoring certificate expiration and automatically renewing them.<\/p>","protected":false},"excerpt":{"rendered":"

An SSL certificate is the core digital certificate that enables secure HTTPS communication, utilizing asymmetric encryption for data encryption and authentication. This article provides a comprehensive guide, from the basics to advanced topics, explaining in detail how SSL certificates work, their key components, how to choose the right type, and the process of applying for and deploying them. It also discusses the significant impact of SSL certificates on SEO rankings and user experience.<\/p>","protected":false},"author":7,"featured_media":0,"template":"","meta":{"_acf_changed":false,"footnotes":""},"tags":[326,11,327,329,338],"knowledge_category":[277],"class_list":["post-12402254","knowledge_post","type-knowledge_post","status-publish","hentry","tag-https-guide","tag-ssl-certificate","tag-digital-certificate","tag-data-encryption","tag-cybersecurity","knowledge_category-ssl-certificate"],"acf":{"site_seo_keywords":"SSL\u8bc1\u4e66,HTTPS,TLS,\u6570\u5b57\u8bc1\u4e66,EV\u8bc1\u4e66,Let's Encrypt,\u57df\u540d\u9a8c\u8bc1\u8bc1\u4e66,\u7f51\u7ad9\u52a0\u5bc6"},"_links":{"self":[{"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/knowledge_posts\/12402254","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/knowledge_posts"}],"about":[{"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/types\/knowledge_post"}],"author":[{"embeddable":true,"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/users\/7"}],"version-history":[{"count":3,"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/knowledge_posts\/12402254\/revisions"}],"predecessor-version":[{"id":12402259,"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/knowledge_posts\/12402254\/revisions\/12402259"}],"wp:attachment":[{"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/media?parent=12402254"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/tags?post=12402254"},{"taxonomy":"knowledge_category","embeddable":true,"href":"https:\/\/www.likacloud.com\/en\/wp-json\/wp\/v2\/knowledge_category?post=12402254"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}