Certifying Authority

• A certifying authority provides authentication.

• A certifying authority is a trusted third party that vouches for the identity of individuals and organizations.
  • Modern browsers have digital certificates of many certifying authorities pre-installed.

• Having a certifying authority sign a digital certificate:
  • Defeats a man-in-the-middle attack.
  • Enables the key agreement protocol.

What is a man-in-the-middle attack?

---

---

© 2006 John Michael Pierobon

Notes