The one-time pad Alice·● Bob want to say 10111001 10111001 he110=01101001 个 ⊕ 10111001 11010000 Alice and Bob share a secret key Bob can recover the message, but to Eve it looks totally random!
The one-time pad Alice 10111001 Bob want to say 10111001 hello = 01101001 ⊕ 10111001 11010000 Alice and Bob share a secret key Bob can recover the message, but to Eve it looks totally random!
Secret-key cryptography saopgpwnhx Alice nizpfkel3c OK Bob 10111001 10111001 Easy if they share a secret key ..but the key must be as long as all the messages they will ever exchange!
Secret-key cryptography Alice Bob saopgpwnhx nizpfkel3c OK! Easy if they share a secret key 10111001 10111001 … but the key must be as long as all the messages they will ever exchange!
Enter computation easy hard 953081 ×603749 hard? 575421700669
Enter computation easy 953081 × 603749 575421700669 easy hard? hard
The cryptographic revolution Assuming there exist digital tasks that are hard to reverse-engineer*we can do saopgpwnhx Alice nizpfkel3c Bob OK Eve public key encryption mental poker secure multiparty computation [Diffie-Hellman,Rivest-Shamir-Adleman] [Yao,Blum,Goldreich-Micali-Wigderson]
• Assuming there exist digital tasks that are hard to reverse-engineer* we can do The cryptographic revolution Alice Bob saopgpwnhx nizpfkel3c OK! ??! Eve public key encryption mental poker [Diffie-Hellman, Rivest-Shamir-Adleman] [Yao, Blum, Goldreich-Micali-Wigderson] secure multiparty computation
The foundations of cryptography 953081 ×603749 Is it really that hard? 575421700669 We can't say for sure, but many have tried and failed
The foundations of cryptography 953081 × 603749 575421700669 Is it really that hard? We can’t say for sure, but many have tried and failed