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The Public Key Infrastructure (PKI) is all about certificates in the digital landscapes. It is a powerful security tool that manages public keys used for encryption, certificate distribution, and revocation. The PKI manages network security by allowing the verification of digital certificates and public keys.  

As you browse secure sites on the internet, the computer leverages certificates to build trust with the remote website. An organization that uses the PKI demonstrates its dedication to network security to avoid third-party compromise. Several components of the Public Key Infrastructure help manage the public and private key pairs. A typical PKI is made up of these components.


1. Certificate authority

The certificate authority acts as an independent provider of digital certificates that handles all certificate management aspects. The role of certifying authorities is to issue a certificate and help users verify the certificate’s ownership. In other words, after a client has generated the public-private key pair, they receive a digital certificate from the CA containing the public key attributes. The CA will sign the digital certificate with its private key to show ownership.

The authority is a trusted third party that digitally signs a certificate, approving it to confirm the public key’s ownership. Every certificate from the CA is trusted by all entities that have trust in the authority. It is a critical PKI component because it certifies that a public key belongs to a specific entity. Moreover, its exact role often differs depending on the position within the CA hierarchy.


2. Private and public keys

A public key is used to encrypt and decrypt data. Anyone can encrypt messages using a public key distributed to the public without needing secure storage. It relies on asymmetric cryptography to identify and access a secure network. However, you can only encrypt the messages encrypted by the public key using the corresponding private key. Only the holder of a paired private key can decrypt messages on public keys.

Therefore, the role of a private key is to decrypt a message encrypted using a public key. The encryption is achieved by matching the private key to the public key to establish the key’s ownership and ensure only authorized parties access the message. You can share the public key widely but must keep the private key a secret to prove ownership of the identity.


3. Certificate store

The certificate store is an essential component of the PKI that stores all certificates from multiple authorities. Once the certificate is generated and issued, all the information is added to the store to keep it safe from infringements. The store will contain a trusted root certificate and other public and private keys.

Moreover, stores serve several essential purposes, such as validating the identity of the device. It helps store the private keys to protect them from compromise and ensure only authorized individuals have access. Adding a trusted root certificate to the store allows you to use a third-party certificate without losing the information. Microsoft has a certificate store that comes with pre-installed certificates for easy storage and managing.


4. Digital certificates

A digital certificate can be equated to an identification card that proves legitimacy and ownership of a public key. Once a certificate gets issued to an entity, it will include all the public access and other important information. The digital certificates are issued to identify users and machines and provide assurance about the public key and associated client information.

A user can use this certificate to encrypt or decrypt the information and have access to important information. The digital certificates have several attributes, such as key usage, client authentication, and digital signature. It also contains the subject name that identifies the owner su8has IP address. The certificate authority signs the entire digital certificate after verifying information. There are both hard and soft digital certificates, where a hard certificate is placed on a smart card while a soft certificate is a file placed on the computer.


5. Root certificate authority

This is a trusted authority to verify the user’s identity before issuing the root certificate. The management receives certificate signing requests and verifies their identity before approving them for issuance. Its other roles include identifying devices’ public jet and allowing an entity to check certificate revocation status. The root certificate is a public key certificate with multiple trust paths issued by the custom in-house CA. Moreover, the certificate is valid if it is signed and generated by the root certificate authority. 

Certificate authorities issue multiple certificates, with the root certificate at the top of the order. You will find a list of root certificates on the trust store that must be kept secret in most cases. While certificate authorities don’t sign certificates using the CA root, they create intermediate certificate authorities to separate themselves and the client.


Bottom line

Organizations use a Public Key Infrastructure to show their dedication to network security. Besides, they must maintain the security around PKIs through the use of certificates and keys. Any compromise to the root certificate authority or public key can risk all other certificate validities and securities. Businesses are going for a cloud PKI solution as a cushion against losing essential certificates.