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Public Key Encryption

What are the two main advantages and two main limitations of public key encryption compared with symmetric encryption?

Major limitations of Symmetric Encryption:
  • Key Distribution Problem
  • How do we reach a point where both parties have the same key (chicken-and-egg situation)?
  • Not suitable for authentication: receiver can forge message & claim it came from sender

    • Can classify uses of public key cryptography into 3 categories:

  • encryption/decryption (provide secrecy)
  • digital signatures (provide authentication)
  • key exchange (of session keys) for symmetric encryption