How Does PKI-Based Authentication Work?

February 3, 2022
PKI-Based Authentication

Since the 1970s, public key infrastructure (PKI) authentication has been used to encrypt sensitive data and documents. PKI-based authentication is a method of authentication that revolves around signature encryption. Let’s take a look at how PKI authentication works, its advantages, and its disadvantages.

What is PKI Authentication?

PKI authentication uses a certificate to validate data being sent from one point to another. Each individual has a public key and a private key. Under PKI certificate-based authentication, this public key is shared and used to validate the identity of the person transmitting the data and to decrypt the data itself.

Today, PKI authentication is used for:

  • Email encryption, using services such as OpenPGP and S/MIME.

  • Encryption of documents, using services such as XML Signature and XML Encryption.

  • Authentication services for applications, including web-based applications.

  • Internet of Things authentication, to ensure that data transmitted between them is kept safe.

As you can see, PKI authentication generally uses a third-party system for the validation of a PKI certificate. However, administrators can create their own onboard certificate server or get a certificate-as-a-service, which can allow the organization to manage its own internal PKI certificates and validation.

PKI authentication is most commonly seen in SSL. Whenever you see a locked icon around a website’s address, it is using a form of certificate-based authentication. Without SSL, you don’t know whether your connection is secure. Everyone knows that they shouldn’t enter their credit card or personal information into a site that doesn’t have an SSL certificate, but not everyone knows how SSL works.

Under SSL, the certificate is granted by a third party — which ensures that the data that is being sent is being transmitted correctly, encrypted, and is neither being modified nor compromised. The entirety of the connection is encrypted, which includes the data that is sent from the platform and the data that is received by the platform.

Advantages of PKI Authentication

What are the Advantages of PKI Authentication?

PKI authentication has been in use, in some form, for over four decades. So, there must be a pretty compelling reason why. To some extent, it’s because there’s no real contender for a replacement. PKI authentication and certificate-based authentication is also thoroughly entrenched in many major technologies. But it’s also just a solid method of authentication and security.

There are four major advantages to PKI authentication:

  • You are able to authenticate the source of the data. A third party is able to ensure that you are dealing with a secure, trusted party.

  • You can maintain the privacy of your data. No one without the private keys will be able to unencrypt and view your data.

  • Your data cannot be interfered with. A “middleman” attack cannot be launched that changes the data being sent or received.

  • You can validate the source of the data. Not only is it authenticated, but you can prove you received that data from the given party.

Many in the industry think that PKI can be complex, but when fully automated and cloud-based, PKI-based authentication can be simplified with PKIaaS. Once you have your certificates in place and properly configured, you don’t need to think about the authentication process. Everything is handled automatically — for the user. PKI also dovetails neatly with other solutions like FIDO2 and Windows Hello for Business.

For the administrator, it’s a different situation. Administrating PKI-based authentication systems can be a headache, especially for already over-burdened IT departments. But that’s one of the few disadvantages of PKI authentication, and PKIaaS overcomes that disadvantage.

What are the Disadvantages of PKI Authentication?

There is no perfect security system. Everything has some trade-offs involved. For PKI certificate-based authentication, the downsides are:

  • It can be difficult to manage and maintain a PKI infrastructure. It’s difficult to start PKI certificate-based authentication and then it has to be managed by an internal IT team. While PKI is easy to use, it can be cumbersome to manage. This is why many companies use PKI-as-a-service rather than managing their own.

  • Data can be potentially permanently lost. If all keys are lost, such as during a data disruption or data blackout, it becomes possible that data could be lost forever. The data cannot be decrypted without a key.

  • It can lead to performance issues. PKI encryption can be very resource-intensive, which means that the system load can grow significantly as the system scales.

But despite these disadvantages, PKI authentication remains one of the most popular systems for security management. PKI authentication is used throughout email and the web — and can be used, with some implementation and configuration, across private and air gapped networks.

Are There Alternatives to PKI Authentication?

Alternatives to PKI-based authentication depend primarily on use cases. Two of the major alternatives to PKI authentication are identity-based cryptography and certificateless cryptography. But both these types of authentication services have their own drawbacks. Some believe that blockchain technology can be used to remove PKI authentication, but this has not been adopted on a wider scale.

Because PKI authentication is quite secure for things like the web, email, and network traffic, there are few other options that have been explored. And while some do believe that an alternative for PKI authentication that utilizes fewer resources is necessary, the resources used by PKI authentication have actually become less and less significant — as resources in general have become more available, especially with the proliferation of cloud-based platforms.

Rather than a strict alternative to PKI authentication, most companies instead use an as-a-service provider to manage their certificates. While certificates can be managed on a network domain, it can be a headache to do so.

That’s how PKI authentication works. Like any security solution, there are advantages and disadvantages. PKI authentication works for securing web traffic and network traffic, making it easier for data to flow unencumbered and uncompromised. If you’re interested in strengthening your organization’s security posture but aren’t sure which new technology is best for you, contact the experts at Axiad.

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