Journey Into Cryptography (Computer Science - Khan Academy)

Videos

• 1 What is Cryptography
• 2 The Caesar Cipher
• 3 Caesar Cipher Exploration
• 4 Frequency Fingerprint Exploration
• 5 Polyalphabetic Cipher
• 6 Polyalphabetic Exploration
• 7 The One-time Pad
• 8 Perfect Secrecy Exploration
• 9 Frequency Stability
• 10 Frequency Stability Exploration
• 11 Coin Flip Sequences
• 12 The Enigma Encryption Machine
• 13 Perfect Secrecy
• 14 Pseudorandom Number Generators
• 15 Random Walk Exploration
• 16 The fundamental theorem of arithmetic
• 17 Public key cryptography: What is it?
• 18 The discrete logarithm problem
• 19 Diffie-hellman Key exchange
• 20 RSA encryption: Step 1
• 21 RSA encryption: Step 2
• 22 RSA encryption: Step 3
• 23 Time Complexity (Exploration)
• 24 Euler's totient function
• 25 Euler Totient Exploration
• 26 RSA encryption: Step 4
• 27 What should we learn next?
• 28 Ciphers vs. codes
• 29 Shift cipher
• 30 Caesar cipher encryption
• 31 Caesar cipher decryption
• 32 Caesar cipher frequency analysis
• 33 Vigenere cipher encryption
• 34 XOR bitwise operations
• 35 XOR and the one-time pad
• 36 XOR exploration
• 37 Bitwise operators
• 38 What's next?
• 39 What is modular arithmetic?
• 40 Modulo operator
• 41 Congruence modulo
• 42 Congruence relation
• 43 Equivalence relations
• 44 The quotient remainder theorem
• 45 Modular addition and subtraction
• 46 Modular addition
• 47 Modular multiplication
• 48 Modular multiplication
• 49 Modular exponentiation
• 50 Fast modular exponentiation
• 51 Fast modular exponentiation
• 52 Modular inverses
• 53 The Euclidean Algorithm
• 54 Introduction
• 55 Primality test challenge
• 56 Trial division
• 57 Running time
• 58 Level 2: Measuring running time
• 59 Computer memory (space)
• 60 Binary memory exploration
• 61 Algorithmic efficiency
• 62 Level 3: Challenge
• 63 Sieve of Eratosthenes
• 64 Level 4: Sieve of Eratosthenes
• 65 Primality test with sieve
• 66 Level 5: Trial division using sieve
• 67 The prime number theorem
• 68 Prime density spiral
• 69 Prime gaps
• 70 Time space tradeoff
• 71 Summary (what's next?)
• 72 Randomized algorithms (intro)
• 73 Conditional probability warmup
• 74 Guess the coin
• 75 Random primality test (warm up)
• 76 Level 9: Trial Division vs. Random Division
• 77 Fermat's little theorem
• 78 Fermat primality test
• 79 Level 10: Fermat Primality Test