Public-key Cryptography

Asymmetric cryptography involves a pair of keys, one for encrypting (public) another for decrypting (private). One is private ($K^{-}$), the other is public ($K^{+}$). The key property is that one key cannot be obtained from the other in reasonable computation time

Common forms of Asymmetric Cryptography are RSA and ECC

Two use cases

1. Sender encrypts with public key
   • Only private key can decrypt it
   • Used for confidentiality
2. Owner encrypts with private key
   • Anyone can decrypt as public key is public
   • Used for authentication/proof of ownership