Skip to content Skip to navigation Skip to footer

What Is a Digital Certificate?

Digital Certification Definition

A digital certificate is a file or electronic password that proves the authenticity of a device, server, or user through the use of cryptography and the public key infrastructure (PKI)

Digital certificate authentication helps organizations ensure that only trusted devices and users can connect to their networks. Another common use of digital certificates is to confirm the authenticity of a website to a web browser, which is also known as a secure sockets layer or SSL certificate. 

A digital certificate contains identifiable information, such as a user’s name, company, or department and a device’s Internet Protocol (IP) address or serial number. Digital certificates contain a copy of a public key from the certificate holder, which needs to be matched to a corresponding private key to verify it is real. A public key certificate is issued by certificate authorities (CAs), which sign certificates to verify the identity of the requesting device or user.

What Are the Benefits of Digital Certification?

Digital certificates can be requested by individuals, organizations, and websites. To do so, they provide the information to be validated and a public key through a certificate signing request. The information is validated by a publicly trusted CA, which signs it with a key that provides a chain of trust to the certificate. 

This enables the certificate to be used to prove the authenticity of a document, for client authentication, or to provide proof of a website’s credential.

What Are the Types of Digital Certificates?

There are three different types of public key certificates: a transport layer security (TLS)/SSL certificate, a code signing certificate, and a client certificate.

TLS/SSL Certificate

A TLS/SSL certificate sits on a server— such as an application, mail, or web server—to ensure communication with its clients is private and encrypted. The certificate provides authentication for the server to send and receive encrypted messages to clients. The existence of a TLS/SSL certificate is signified by the Hypertext Transfer Protocol Secure (HTTPS) designation at the start of a Uniform Resource Locator (URL) or web address. It comes in three forms:

Domain Validated

A domain validated certificate is a quick validation method that is acceptable for any website. It is cheap to obtain and can be issued in a matter of minutes.

Organization Validated

This provides light business authentication and is ideal for organizations selling products online through e-commerce.

Extended Validation

This offers full business authentication, which is required by larger organizations or any business dealing with highly sensitive information. It is typically used by businesses in the financial industry and offers the highest level of authentication, security, and trust.

Code Signing Certificate

A code signing certificate is used to confirm the authenticity of software or files downloaded through the internet. The developer or publisher signs the software to confirm that it is genuine to users that download it. This is useful for software providers that make their programs available on third-party sites to prove that files have not been tampered with.

Client Certificate

A client certificate is a digital ID that identifies an individual user to another user or machine, or one machine to another. A common example of this is email, where a sender signs a communication digitally and its signature is verified by the recipient. Client certificates can also be used to help users access protected databases.

Who Can Issue a Digital Certificate?

Digital certificates are issued by CAs, which sign a certificate to prove the authenticity of the individual or organization that issued the request. A CA is responsible for managing domain control verification and verifying that the public key attached to the certificate belongs to the user or organization that requested it. They play an important part in the PKI process and keeping internet traffic secure.

Beneficial Features of Digital Certificates

Digital certificates are becoming increasingly important, as cyberattacks continue to increase in both volume and sophistication. Key benefits of digital certificates include:


Digital certificates encrypt internal and external communications to prevent attackers from intercepting and stealing sensitive data. For example, a TLS/SSL certificate encrypts data between a web server and a web browser, ensuring an attacker cannot intercept website visitors’ data.


Digital certificates provide businesses of all shapes and sizes with the same encryption quality. They are highly scalable, which means they can easily be issued, revoked, and renewed in seconds, used to secure user devices, and managed through a centralized platform.


Digital certificates are crucial to ensuring the authenticity of online communication in the age of widespread cyberattacks. They make sure that users’ messages will always reach their intended recipient—and only reach their intended recipient. TLS/SSL certificates encrypt websites, Secure/Multipurpose Internet Mail Extensions (S/MIME) encrypt email communication, and document-signing certificates can be used for digital document sharing.


Only publicly trusted CAs can issue digital certificates. Obtaining one requires rigorous vetting, which ensures hackers or fake organizations cannot trick victims that use a digital certificate.

Public Trust

Using a digital certificate provides confirmation that a website is genuine and that documents and emails are authentic. This projects public trust, assuring clients that they are dealing with a genuine company that values their security and privacy.

Differences Between Digital Certificate and Digital Signature

A digital certificate is a file that verifies the identity of a device or user and enables encrypted connections. A digital signature is a hashing approach that uses a numeric string to provide authenticity and validate identity. A digital signature is typically fixed to a document or email using a cryptographic key. The signature is hashed, and when the recipient receives it, it performs that same hash function to decrypt the message.

How Fortinet Can Help?

Fortinet enables organizations to establish a secure virtual private network (VPN) connection using digital certificates. For example, Fortinet users can secure their connection by using an Internet Protocol security (IPsec) VPN with digital certificateFortiGate digital certificates also enable users to authenticate their VPN connection.