

What is a Public Key Infrastructure or PKI?
Nowadays, no one doubts that the apogee of the Digital Transformation is bringing us numerous advantages to our lives; faster management, with more security… but it is undeniable that, along with these benefits, we are also facing the not so positive scenario of cyber-attacks, which are becoming more and more sophisticated. And all of this forces both organizations and users to bet on robust and reliable protection and security, through encryption, for data infrastructures.
Critical infrastructures such as financial and health institutions or Public Administration, as well as the business sector, cannot afford the slightest vulnerability in the protection of their sensitive information and must therefore secure their processes as well as keep a clear record of their processes.
For this robust protection of sensitive data, secure electronic transactions and reliable digital identification, the PKI, or Public Key Infrastructure, is the best option.
In this post we will discuss what public key infrastructure is, why it is important and how it can help you to protect both your data and your customers’ data.
What is a Public Key Infrastructure or PKI?
A PKI is a cybersecurity technology infrastructure that integrates a Root CA or Certification Authority for the issuance of digital certificates together with the public key cryptographic keys that are stored and safeguarded in an HSM for the encryption process.
When the Registration Authority (RA) and the Validation Authority (VA) are added to this Root CA, a PKI becomes the best technological ally for the issuance, validation and revocation of digital certificates, used both to confirm the identity of the signer and the integrity and non-repudiation of the signed document.
An example where PKI technology is used is in the encryption of web pages. When we see the padlock on a URL (as in the example of the Realsec website) we know that a PKI has been used, specifically a Root Certification Authority (CA) for the creation of the SSL trust digital certificate, which indicates that we can navigate, make transactions such as a purchase or fill out a form with our data, in a secure way and in a secure site that gives us online confidence.
In addition, as we discussed in a previous blog post, PKI is used for digital signatures.


The 411 on Encryption
PKI technology is based on the encryption of information by means of keys generated and stored in a HSM or Hardware Security Module, where the data is also encrypted so it can only be decrypted using another key. This is done either through symmetric key encryption or asymmetric key encryption.
Symmetric key encryption requires the hardware to have a private key installed for data decryption. Devices that do not have such a key will not be able to decrypt any encrypted data, as this is the basis of its security.
With asymmetric key encryption, a pair of keys, the public key and the private key, are needed to encrypt and decrypt the information. The public key (in the form of a digital certificate) must be shared with the sender of the data to be able to encrypt it. The private key is used by the recipient to decrypt the data encrypted by the sender.
As its name indicates, the public key is public, and anyone can access it; but the private key is personal and non-transferable.
An example of a PKI public key would be the example of the padlock, the web’s SSL trust certificate.
How is PKI used?
As mentioned, PKI is used to protect websites. But they don’t just do that.
PKI can be used to:
- Checking and verification of the digital identity of websites, services, email customers and software.
- Encrypt and decrypt data.
- Securing online data such as form submissions and e-commerce sales data.
- To insert digital signatures to e-mails, documents and software.
In simple words, PKI makes it possible to protect information and data and also to authenticate them, essential aspects for cybersecurity in data management processes.
Not only Defense and Government Agencies implement this public key infrastructure in their technological core, but other organizations such as financial or health entities find in PKI a critical technological ally for the data security. This has a positive impact on their reputation both with their customers and with the society.
Therefore, we see that PKI is a strategic axis in the cybersecurity of various types of companies, both for themselves and for their users, and a tough enemy of hackers.
How can PKI help you?


PKI focuses on three basic functions:
- Authentication of the web site and its server.
- Provides the certificate that encrypts and decrypts the information.
- Avoids the fraudulent alteration of the data, providing integrity to both the signer and the signed.
For all these reasons, in addition to providing a good image for a company, as mentioned above, with a PKI, both companies and users can rest assured in web browsing and other transactions associated with their data (personal information, payments, etc).
If a website does not have the digital certificate of authentication issued by a PKI, the different web browsers will display a warning to visitors about it is not a secure website and will invite them to leave the site.
As an organization that manages and sends sensitive information, you should consider the use of a PKI as a strategic technological ally for data protection and minimization of fraud risks.
PKI is capable of encrypting data, which can be encrypted so that it can only be decrypted and accessed by devices that have the correct key, invalidating unauthorized or fraudulent access to this data.
When accessing to data, how can we be sure that it is trustworthy? By the authenticity and integrity that we have pointed out that PKI brings to both the signer and the signed.
In addition, you can learn more about PKI in this post previously published in our blog.
We are aware of the complexity and numerous functions and advantages that a PKI or Public Key Infrastructure gives us and therefore we know that it is difficult to summarize everything in a blog post. That is why we encourage you to contact Realsec and learn more about how we can help you to protect your data.
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