Objective: Know and understand digital certificates including its purpose and contents
This section provides detailed information about digital certificates, covering their purpose, contents, and importance in ensuring online trust and security. Understanding digital certificates is crucial for responsible and safe use of ICT.
What is a Digital Certificate?
A digital certificate is an electronic document that verifies the identity of a website or individual. It's essentially a digital version of a passport, confirming that a website is who it claims to be and that the data exchanged with it is authentic and hasn't been tampered with.
Purpose of Digital Certificates
Digital certificates serve several important purposes:
Authentication: Verifies the identity of a website or user.
Encryption: Enables secure communication by encrypting data transmitted between a user's device and a website.
Data Integrity: Ensures that data transmitted hasn't been altered during transit.
Non-repudiation: Provides evidence that a specific entity performed an action.
Contents of a Digital Certificate
A digital certificate contains several key pieces of information:
Field Name
Description
Subject Name
The name of the entity the certificate is issued to (e.g., a website domain name or a person's name).
Public Key
A cryptographic key used for encryption and decryption. It's part of the key pair associated with the certificate.
Issuer Name
The name of the Certificate Authority (CA) that issued the certificate.
Serial Number
A unique identifier for the certificate.
Issue Date
The date the certificate was issued.
Expiry Date
The date after which the certificate is no longer valid.
Digital Signature of the CA
A cryptographic signature from the CA, verifying the authenticity of the certificate.
How Digital Certificates Work
Digital certificates rely on public-key cryptography. Here's a simplified explanation:
A website owner generates a key pair: a public key and a private key.
The public key is included in a digital certificate.
The website submits the certificate to a Certificate Authority (CA).
The CA verifies the website owner's identity and issues a digital certificate containing the public key and other information.
When a user visits the website, their browser checks the certificate to verify the website's identity and ensure a secure connection.
Importance of Digital Certificates
Digital certificates are essential for:
Building trust online: They help users verify that they are communicating with legitimate websites.
Protecting sensitive data: They enable secure communication channels, preventing eavesdropping and data tampering.
Ensuring online transactions are secure: They are crucial for e-commerce and other online financial activities.
Without digital certificates, online transactions and secure communication would be significantly more vulnerable to fraud and security breaches.
Suggested diagram: A simplified illustration showing a user's browser checking a digital certificate from a Certificate Authority (CA) before establishing a secure connection with a website.