{"id":1906,"date":"2020-12-16T16:48:41","date_gmt":"2020-12-16T16:48:41","guid":{"rendered":"https:\/\/sectigostore.com\/blog\/?p=1906"},"modified":"2023-06-14T20:42:25","modified_gmt":"2023-06-14T20:42:25","slug":"public-key-vs-private-key-how-do-they-work","status":"publish","type":"post","link":"https:\/\/sectigostore.com\/blog\/public-key-vs-private-key-how-do-they-work\/","title":{"rendered":"Public Key vs Private Key: How Do They Work?"},"content":{"rendered":"\n

Explore the roles of the public key and private key in public key cryptography and learn how they make secure third-party communications possible<\/h2>\n\n\n\n

Public key vs private key \u2014 these are two very important terms to understand and differentiate in public key cryptography, or what\u2019s known as asymmetric encryption. You see, public key cryptography is what makes it possible to communicate securely with people you do or don\u2019t know across the internet by enabling you to identify them and encrypt your communications. Having both a public key and private key is necessary for this process.<\/p>\n\n\n\n

But what are a public key and private key? Why do they matter, and what are the differences between them? In this article, we\u2019ll talk about public key vs private key and their roles in data privacy and identity verification.<\/p>\n\n\n\n

Public Key vs Private Key: The Differences Between Them<\/h2>\n\n\n\n

Encryption<\/a> means converting plaintext data in a gibberish format in a way that no unauthorized person can read, interpret, or alter it without a special key. A cryptographic key<\/a> is a long string of random, unpredictable characters. If you use one key to encrypt and decrypt data, then it means you\u2019re using symmetric encryption. <\/p>\n\n\n\n

\"Public<\/figure>\n\n\n\n

But if you\u2019re using two separate keys \u2014 one to encrypt data and the other to decrypt it \u2014 then you’re using asymmetric encryption<\/a> (public key encryption). The keys are known as the public key (encryption key) and the private key (decryption key).<\/p>\n\n\n\n

\"Public<\/figure>\n\n\n\n

As we pointed out earlier, there are two separate keys involved in public key cryptography. Imagine a vault that has two separate keys. One can lock the vault, but the same key can\u2019t open it. This means you\u2019d need a different key to unlock the vault. In public key cryptography, it\u2019s much the same way: there are two keys \u2014 one that can encrypt the data and the other that can decrypt it. These keys are separate yet mathematically related to each other. That\u2019s because they\u2019re generated using an asymmetric algorithm that binds the public key to the private one.<\/p>\n\n\n\n

To learn more about the differences between them, be sure to check out this article on the differences between asymmetric vs symmetric encryption<\/a>.<\/p>\n\n\n\n

What Is a Public Key & How Does It Work?<\/h3>\n\n\n\n

Within public key infrastructure, the public key encrypts the data. It\u2019s known as the public key because it can be openly distributed, and anyone can use it for encryption. As soon as the data is encrypted using a public key, you can neither interpret nor guess the original content of the data from the ciphertext nor use the same key (i.e., public key) to unlock it.<\/p>\n\n\n\n

Your public key is generated using complex asymmetric encryption algorithms. The length of the public key depends upon the algorithm it is made with. In general, the key size varies from 128 bits to 4096 bits. The Certificate Authority\/Browser Forum (CA\/B Forum) provides guidance for the ideal minimum public key size. For example, based on the CA\/B Forum\u2019s current guidelines<\/a>, all CAs shall confirm that:<\/p>\n\n\n\n