Lecture Topic: Public Key Infrastructure

PKI protects information assets in several ways
- Authentication (using digital certificates)
- Integrity (content not changed)
- Privacy (secure information)
- Authorization (access control)
- Nonrepudiation (can validate action)

The Diffie Hellman key exchange provides no authentication of the two communicating partners, so it is vulnerable to man in the middle attacks

Digital envelopes are an application of public key encryption which can be used to protect a symmetric key, which can be used to protect a message without needing to first arrange for sender and receiver to have the same secret key

Randomness
Two criteria are used to valid a sequence of random numbers:
- Uniform Distribution: The distribution of the numbers should be uniform, that is the frequency of occurrence of each of the number should be approximately the same
- Independence: No one value in the sequence can be inferred from the others

Random vs Pseudorandom
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