COMPSCI 92L Lecture Notes - Lecture 7: App Inventor For Android, Pseudorandom Number Generator, Modular Arithmetic
Document Summary
Whitfield diffie and martin hellman designed an unbreakable encryption code for the. Enigma (wwii machine), but alan turing broke it eventually. Apple"s password encryption algorithm makes it harder to break into someone"s phone with the wrong password because you have to wait longer with each wrong submission. Apple v fbi case: apple, the plaintiff, won a major court victory against the fbi by refusing to create a backdoor to decrypt the san bernadino shooter"s iphone. Caesar cipher: use single number to encrypt/decrypt a number. The number is the number of lexographic letters off you transfer each time. Diffie-hellman one-way function: easy in one direction, hard in reverse direction. Ex. of x1"s private color, x2"s private color, when both colors are mixed, you get mixed color. Hard to go back from mixed color to separate private colors. Bob picks secret color, so does alice. Bob #008000, alice #ff00ff both mix with secret. Bob sends to alice and vice versa.