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Jon MarienStudy Desk

Security+General concepts

PKI and certificates

Outline only. PKI is the system that lets strangers trust a public key. The crypto note stops just short of it.

8 min read · Outline, not a finished note

Outline. This module is on the map so you can track it. The page below is a writing checklist, not finished study material.

Objectives

  • Define a certificate as a signed binding between a name and a key
  • List the trust failures a finished note should cover
On this page
  1. TODO
  2. Checklist

TODO

Concept note only. No instructions for minting a rogue authority.

Checklist

  • A certificate binds a public key to a subject, signed by an issuer. Trust comes from trusting that issuer, directly or through a chain.
  • Validation is more than “not expired.” The name has to match, the chain has to be valid, and revocation has to be considered.
  • Private keys stay private. A certificate is public. Mixing those up is a common exam miss. The cryptography note introduces the distinction.
  • Use cases to mention later: TLS server identity, code signing, and client certificates as an authentication factor.
  • Operational issues: expiration, rotation, and what breaks when a widely trusted issuer is distrusted. Those are availability problems caused by an identity control.
  • Do not include steps for installing a hostile root or for forging a signature.

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