DOMAIN 1

Self-Signed Certificate

• A certificate that you create and sign yourself, not by a trusted Certificate Authority (CA).

• Used for:

  • Internal testing

  • Private networks

• Example: You make your own certificate on your laptop just to test HTTPS locally — it works, but no one else trusts

CRL Certificate (Certificate Revocation List)

• A list of digital certificates that have been revoked (no longer valid).

• Used for: Checking if a certificate is still trustworthy.

• Example:
  If a company’s key is stolen → that certificate goes on the CRL list so browsers reject it.

Web of Trust

An alternative to a centralized CA is a "web of trust," where multiple individuals sign each other's certificates. If you trust a friend who has signed a third party's certificate, you can trust that third party.

Wildcard Certificate

• A certificate that secures a domain and all its subdomains using a * (wildcard symbol).

• Used for:

  • Simplifying HTTPS setup for multiple subdomains.

• Example:
  *.example.com covers:

  • sales.example.com

  • support.example.com

  • mail.example.com

  • all others automatically