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Public-key Cryptography

Last updated Apr 7, 2022 Edit Source

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

Can theoretically encrypt using private key but anyone with public key can decrypt!