Digital Certificates

What are digital certificates?

Digital certificates are electronic documents that confirm the identity of a server, website, or an individual during an online transaction. They help maintain privacy, prevent data breaches, and ensure communication integrity. 

Certificate authorities (CAs) issue a digital certificate to an individual after confirming the authenticity of their identity. A website receives this digital certificate when the user visits the website using a hypertext transfer protocol secure (HTTPS). This certificate contains a key that the browser uses to encrypt data before sending it to the website. Meanwhile, the website’s server holds the corresponding key to decrypt the data. 

Encryption ensures the transactions remain safe from online attackers, eavesdropping, or data tampering. Many businesses and professionals use decentralized identity solutions to reduce the cost of provisioning and issuing digital certificates. It also offers end users a privacy-preserving identity verification method.

Types of digital certificates

Digital certificates commence with a root certification authority. Here, a trusted organization issues certificates attesting to the sender’s identity. Below are seven common types of digital certificates issued. 

• Transport layer security/Secure sockets layer (TLS/SSL) certificate encrypts information between a server and a browser when installed on a server. Domain-validated, organization-validated, or extended-validation are three TLS/SSL certificate types.
• A code signing certificate proves the authenticity of the files downloaded online. Developers or publishers sign the files to ensure they’re genuine and users can download them.
• Client certificates are digital IDs validating an individual’s identity to another user or machine like an email address. A sender signs a communication digitally, and the recipient verifies the signature.
• User certificates verify user details. It’s bound to a single user and provides identity and encryption services for a single entity.
• Signature-verification certificates have a public key that authenticates the credential's validity and tracks any modifications or tampering after the file has been signed.
• Public key certificates function much like passports in their role. Authorized entities issue this certificate to identify the credential holder. 
• Object signing certificates refer to digitally signing an object. Verifying the sign provides details regarding the object’s ownership.

Contents of a digital certificate

A digital certificate is made up of different pieces of information Iike the owner of the certificate and the authority issuing it. Here are the major components of a digital certificate: 

• Name of the owner: It’s a unique identifier that includes not only the general name of the owner but also the organization and other distinguishing information about the owner.

• Public key: Another component is the owner's public key. A public key helps to encrypt a message. 

• Issue date: It also includes the date on which the certificate is issued.

• Expiry date: It also mentions the date on which the certificate expires.

• Name of issuing CA: Certificate authorities (CA) sign the certificates to prove the validity and authenticity of the organization that requests it. 

• Issuing CA digital signature: This signature validates an extracted certificate and the public key the certificate uses. 

Use cases of digital certificates

Individuals and businesses widely use digital certificates to safeguard information against cyber attacks during transactions. Below are some transactions that use a digital certificate. 

• Debit and credit card security: Cards are embedded with digital certificates to ensure that bank and merchant account transactions are safe and secure.
• Email providers: Secure email uses digital certificates to distinguish one user from another and for electronic document signing.
• Digital payment companies: Digital payment companies apply digital certificate technology to authenticate ATMs, point-of-sale equipment, and other payment systems.
• Websites: Websites use digital certificates to secure web browser and server communications.
• Hardware manufacturers: Computer hardware manufacturers use device cloning to install digital certificates in cable modems to prevent broadband service theft.

Digital certificate vs. digital signature

Digital certificates are a group of electronic files or passwords issued by trusted authorities attached to electronic communications to prove the authenticity of the sender, device, or server.

It uses public key cryptography to ensure secure communication between parties. 

Certificate authorities are trusted third parties responsible for issuing digital certificates. They can be commercial ventures or local entities, depending on the requirements of one’s application.

A digital signature is a hashing model that authenticates and validates a user’s identity with a numeric string. It’s embedded in an email or document with cryptography technology. It performs the hash function to decrypt the message. A digital signature may depend on the distribution of public keys in digital certificates. 

Learn more about electronic signatures and understand how individuals sign documents online.