When it comes to protecting data on the internet, public key infrastructure is crucial. The encryption framework is a collection of tools and procedures used to secure and verify digital communications. PKI relies on cryptographic public keys tied to a digital certificate to verify the identity of the sender of a digital message.
Certificate authorities (CAs) are authoritative organizations that issue digital certificates, resembling digital passports that verify the sender’s identity. Integrating internal business communications with PKI solutions ensures that only the intended recipient and sender reads the message and there’s no tampering with it while in transit.
How Does PKI Works?
1. PKI Functions Through the Verification of Individual Users and Servers
Authentication is the first phase of a public-key infrastructure system. You can use asymmetric encryption to verify the identity of your server, clients, or yourself via digital certificates like SSL/TLS and client certificates. (Recall that public and private keys are the basis of asymmetric encryption.) Using the following example of a connection to Amazon.com, let us consider a simple step-by-step description of how authentication works:
For instance, the web client communicates with the Amazon.com server to retrieve the server’s certificate and public key. Afterward, the client checks the CA that issued the certificate to see if it is on its list of trusted CAs. (Note that you cannot forge digital signatures, meaning they are basis of the trust in this system. That means your browser will know it is talking to the correct server if the trust chain checks out.
Following this, the client uses the certificate’s public key to encrypt some data before sending it to the server. If the server can decipher it, it means it communicates with the intended server and has the proper private key.
The user’s web client and your server initiate an SSL or TLS handshake to pave the way for this procedure (hence producing a safe, encrypted connection in the end). This method reduces the possibility of eavesdropping and man-in-the-middle (MitM) attacks by letting the client do the following:
2. Collaboratively establish a set of secure encryption parameters for both parties
After server authentication, you can generate a one-of-a-kind session key to use for encrypted communication between the client and server (as described above).
So, what happens if the server has to verify your identity? That’s conceivable as well. In that situation, you’ll need a certificate issued by a CA that the server recognizes (a client certificate, also known as an email signing certificate). The server performs a similar process (in reverse) by verifying your digital certificate before granting access to the server’s apps or content.
3. PKI Also Works Through Encryption
For the encryption and decryption of information, public key infrastructure employs asymmetric, mathematically related keys. Essentially, we’re discussing transforming a legible message (plaintext) into an unreadable one (ciphertext). Once it reaches the intended recipient, it must be decrypted or unscrambled.
4. Methods of Encryption
An old-fashioned shift cipher (substitution cipher), most popularly known as the Caesar cipher, is a straightforward encryption method. For deciphering messages, experts use the secret key to “shift” the plaintext characters to a certain number of spaces. If your key is 6, the word “CERTIFICATE” becomes “IKXZOLOIGZK” since six spaces displace each letter.
Without a doubt, this is a primitive sort of encryption. Since the days of ancient Roman note delivery by horse or boat, modern cryptographic procedures have come a long way. Data, messages, and other sensitive information can now be encrypted (and decrypted) with supercomputers and other technological advancements on our side.
In the Public Key Infrastructure (PKI), the technique encrypts data using a public key and decrypts using a private key.
PKI, though, has more than that up its sleeve. PKI also facilitates the creation of symmetric encryption keys, which is an additional useful feature. Even though symmetric keys are less secure than their asymmetric counterparts, they are nonetheless extremely useful due to their ability to provide faster and less resource-intensive communication. Without getting too technical, PKI provides the security of asymmetric encryption while maintaining the ease of use of symmetric encryption.
5. PKI Ensures Reliable After the Server authenticates Data Integrity
Public key infrastructure plays a crucial role by verifying the integrity and authenticity of data, ensuring data comes from a reliable source without compromising its integrity. One way it does this is by allowing you to attach a legally binding digital signature to electronic correspondence, programs, and data. In addition, you can use the CA’s private key to sign each digital certificate.
So many people always seem to overlook this point. An invalid certificate will compromise the security of your website. IT includes poor installation or configuration, certificate expiration, or the extremely unlikely revocation by the issuing CA. Worse of all, it could bring your entire system down with it.