The language of cryptography ⑥学Alice's ⑥学Bob's encryption K decryption key B key plaintext encryption ciphertext decryption plaintext algorithm algorithm symmetric key crypto:sender,receiver keys identical public-key crypto:encryption key public,decryption key secret (private) 8:Network Security 8-9 8: Network Security 8-9 The language of cryptography symmetric key crypto: sender, receiver keys identical public-key crypto: encryption key public, decryption key secret (private) plaintext ciphertext plaintext K A encryption algorithm decryption algorithm Alice’s encryption key Bob’s decryption key K B