But how does PKI work?<\/p>\n\n\n\n
In our previous articles, we’ve learned what PKI is<\/a>. We’ve explored its fundamental components and practical uses<\/a>. Today, we’ll take it a step further by peeking behind the curtain to understand how public key infrastructure works to protect your organization\u2019s data from the bad guys.<\/p>\n\n\n\n Editor’s Note:<\/strong> This post is the third and final article in a three-part series that dives into the details of PKI technology. This series explores the roles of PKI technology in IT security<\/a>, what PKI uses and applications<\/a> small and mid-size businesses can enjoy, and how PKI technology works<\/a> from a technical perspective. <\/em><\/p>\n\n\n\n PKI is the \u201csecret sauce\u201d of internet security. It\u2019s what makes secure data and communications over the internet possible.<\/p>\n\n\n\n From online payments to email exchanges and even software downloads, PKI:<\/p>\n\n\n\n The way PKI works is by using trusted certification authority\u2019s<\/a> (CA’s) issued digital certificates to establish a “chain of trust” (more on that momentarily) between two communicating parties (e.g., users, services, or devices). This public key cryptography-based digital trust enables one or both parties to authenticate and encrypt the channel used to exchange data \u2014 all while protecting the integrity of the data itself.<\/p>\n\n\n\n Yup, PKI works in a nutshell by facilitating the following:<\/p>\n\n\n\n In a traditional connection, PKI enables a web server to prove its identity to a connecting client as part of the TLS handshake. (We\u2019ll speak more about that a little later.) However, when the client uses a personal authentication certificate, PKI enables it to authenticate as well in a process known as mutual authentication.<\/p>\n\n\n\n Of course, this is a simplified overview of PKI<\/a>. Let’s answer the question “how does PKI work?” by going through its key concepts step by step.<\/p>\n\n\n\n Don\u2019t have time to go through all of the steps in detail? Get an overview of all the PKI basics in 180 seconds<\/a>. <\/p>\n\n\n\n As a certificate requestor, you must generate a public-private key pair as part of your certificate signing request (CSR). You\u2019ll keep the private key to yourself (store it securely!) and send your public key to a trusted certificate authority (CA) with your request for a digital certificate. Which type of digital certificate? The answer depends on your specific needs.<\/p>\n\n\n\n Organizations are spoiled with options. There are several types of certificates, each of which protects data in different situations. Here are a few quick examples of PKI certificates you\u2019ll commonly find used by small and mid-size businesses:<\/p>\n\n\n\n To answer a question like “how does PKI work?” you first need to understand validation and its role in trusted digital identities. For this example, we\u2019ll assume you request an EV SSL\/TLS certificate for your business\u2019s website.<\/p>\n\n\n\n Since you requested the highest level of identity assurance, the CA verifies your organization following a more in-depth vetting process. This process may take slightly longer than usual, but it’s well worth it. In exchange, your website will get the ultimate level of trust. Once the validation is completed, the CA issues a certificate that includes the public key and your organization’s information.<\/p>\n\n\n\n After you\u2019ve received and installed the certificate on your web server, you\u2019re essentially good to go. As soon as a user visits your website, the client initiates what\u2019s known as the TLS handshake<\/a>, a process that relies heavily on PKI.<\/p>\n\n\n\n This process enables one or both parties (the latter in the case of mutual TLS authentication) to authenticate and exchange information about which cryptographic ciphers they support. Afterward, the server picks the algorithm to use for the secure communication session.<\/p>\n\n\n\n In a traditional TLS handshake, when the user\u2019s client attempts to establish a connection to your website:<\/p>\n\n\n\n Before moving on to the next step in answering how PKI works, let’s quickly clarify what a chain of trust<\/a> is and how PKI works with it. A chain of trust is a set of digital certificates that link your SSL\/TLS certificate back to the CA that issued it, much like how your genealogical tree links you to your ancestors. It’s this origination method that PKI uses to enable the client to verify whether your server’s identity is legitimate.<\/p>\n\n\n\n This set usually includes three certificates:<\/p>\n\n\n\n So, how does PKI work with the chain of trust to promote confidence in your website? Remember when we said that the server sends the SSL\/TLS certificate and its public key to the client? Here’s where the chain of trust comes in.<\/p>\n\n\n\n The client chains the SSL\/TLS certificate back to the root, passing through the intermediate, just as if it were following an imaginary \u201cAriadne’s thread\u201d:<\/p>\n\n\n\n After successful authentication, in our example, PKI creates a secure (encrypted) communication channel between the user’s browser (i.e., client) and your server. That’s how PKI works to protect your customers\u2019 and organization\u2019s data in transit (e.g., credit card information, passwords, and social security numbers) from prying eyes.<\/p>\n\n\n\n In general, PKI utilizes a mix of asymmetric and symmetric encryption<\/a>:<\/p>\n\n\n\n With SSL\/TLS, you get the best of both worlds: the enhanced security of asymmetric encryption initially paired with the speed and performance of symmetric encryption for the rest of the session.<\/p>\n\n\n\n Hold on. All of these things occur in the background, unbeknownst to site visitors and other prospective customers. So, how can these individuals know that the connection is secure? By seeing the HTTPS indication at the beginning of the URL (and a padlock near the browser\u2019s web address bar in some clients, such as Firefox).<\/p>\n\n\n\n That’s how public key infrastructure works to secure data in transit. But PKI can do much more for your business. And this is what we\u2019re going to explore next, as our backstage trip hasn’t come to an end yet. There are still a few things to explore before we go back to the digital world’s stage. So, keep on reading.<\/p>\n\n\n\n <\/a>Now that we understand how PKI works from a technical point of view, it’s time to discover a few of the ways that public key infrastructure works to help secure your organization’s communications and sensitive data in a more practical sense:<\/p>\n\n\n\n Find even more practical examples of how PKI works to pave the way toward zero-trust security in our dedicated article<\/a> on PKI uses and applications<\/a>.<\/p>\n\n\n\n You’ve just learned how PKI works to facilitate data confidentiality, integrity, and authenticity and how it keeps your communications safe over insecure networks. In many ways, public key infrastructure is the MVP of internet security.<\/p>\n\n\n\n However, there’s a catch: PKI can’t work its magic without robust key and certificate management. Managing keys and keeping them secure is a big deal for PKI. It would be like asking a magician to do his tricks without his hat and wand.<\/p>\n\n\n\n Therefore:<\/p>\n\n\n\n Follow these tips, and PKI will work like a charm.<\/p>\n\n\n\n Here ends our grand tour of looking behind the scenes of how PKI works. We hope this article answered your questions so that you’ll never again have to wonder, “How does public key infrastructure work?\u201d<\/p>\n\n\n\n Now, it’s your turn. Use X.509 digital certificates to secure your organization, systems, and customers with PKI. In times when AI-powered attacks increase the chances of breaches, PKI can help businesses of all sizes secure their assets and protect customers’ privacy while offering a robust authentication system. <\/p>\n","protected":false},"excerpt":{"rendered":" You enjoy the benefits of PKI every day, but have you ever wondered what goes on behind the scenes? Learn how public key infrastructure works to ensure data security and…<\/p>\n","protected":false},"author":23,"featured_media":3783,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","tve_updated_post":"","tve_custom_css":"","tve_user_custom_css":"","tve_globals":{},"tcb2_ready":0,"tcb_editor_enabled":0,"tve_landing_page":"","_tve_header":"","_tve_footer":""},"categories":[13,9],"tags":[325,324,323],"class_list":["post-3782","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cyber-security","category-encryption","tag-how-does-pki-work","tag-pki-it-security","tag-pki-technology","post-with-tags"],"yoast_head":"\nWhat Is PKI? Public Key Infrastructure Explained in 60 Seconds<\/h2>\n\n\n\n
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A Quick Recap of What It Does for Organizations Globally<\/h3>\n\n\n\n
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How Does PKI Work? An Overview<\/h2>\n\n\n\n
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How Public Key Infrastructure Works (Step #1): Certificate Issuing<\/h3>\n\n\n\n
Certificate Types<\/h4>\n\n\n\n
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The Certificate\u2019s Validation Process<\/h4>\n\n\n\n
![\"How](\"https:\/\/sectigostore.com\/blog\/wp-content\/uploads\/2025\/06\/how-pki-works-issuance-1024x581.jpg\")
How Public Key Infrastructure Works (Step #2): Authentication<\/h3>\n\n\n\n
The TLS Handshake<\/h4>\n\n\n\n
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![\"An](\"https:\/\/sectigostore.com\/blog\/wp-content\/uploads\/2025\/06\/how-pki-works-handshake-authentication-1024x572.jpg\")
The Chain of Trust<\/h4>\n\n\n\n
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![\"How](\"https:\/\/sectigostore.com\/blog\/wp-content\/uploads\/2025\/06\/pki-trust-chains-1024x500.jpg\")
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How Public Key Infrastructure Works (Step #3): Encryption<\/h3>\n\n\n\n
![\"An](\"https:\/\/sectigostore.com\/blog\/wp-content\/uploads\/2025\/06\/how-pki-works-authentication-encryption-1024x570.jpg\")
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How Does PKI Work to Protect Your Organization? 8 Practical Examples<\/h2>\n\n\n\n
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PKI Needs a Proper Key and Certificate Management to Be Effective<\/h2>\n\n\n\n
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Final Thoughts About a Look at the Inner Workings of Public Key Infrastructure<\/h2>\n\n\n\n