Public Key Cryptography

Public Key Cryptography uses two keys, a Public key and a Private key. PGP Uses the RSA Cryptosystem. The basic premise: Using one key to encrypt requires the other key to decrypt:

• Private Key
  • User keeps secret -- no one should see this key
  • Encryption creates Digital Signature
  • Decryption opens sealed messages
• Public Key
  • User makes public -- anyone can see this key
  • Encryption seals messages
  • Decryption verifies Digital Signature

• Users can distribute Public Keys to anyone
• Knowing the Public Key does not help an attacker find the Private Key
• Has Digital Signatures