Practice and study of secure communications
| Name | Preview | Code | Difficulty |
|---|---|---|---|
| Security Functions | Complete a function that takes input x and return the remainder of x divided by 11. | C++ | Easy |
| Security Functions II | Complete the function that takes x as the input and returns (x*x) | C++ | Easy |
| Security Bijective Functions | You'll be given an integer n and a function f:X→X where X={1,2,3,...,n}. Determine whether the function is a bijective function or not. | C++ | Easy |
| Security Function Inverses | Find the inverse of a given function f. | C++ | Easy |
| Security Permutations | Given a function f, find f(f(x)) for all x ∈ {1,2,3,...,n}. | C++ | Easy |
| Security Involution | Determine whether function f is an involution or not. | C++ | Easy |
| Name | Preview | Code | Difficulty |
|---|---|---|---|
| Security - Message Space and Ciphertext Space | Given a message, you need to find what message you obtain if you shift each digit in the message string ( 1 to the right and cyclic). | C++ | Easy |
| Security Key Spaces | Consider a message that consists of decimal digits and a key, e, which operates by shifting each digit by e places. Find the corresponding cipher text. | C++ | Easy |
| Security Encryption Scheme | Count the number of bijections and the number of keys that produce different encryption functions. | C++ | Easy |
| Name | Preview | Code | Difficulty |
|---|---|---|---|
| PRNG Sequence Guessing | Given last ten output values of random.nextInt(), guess the next value to be output by the generator. | C++ | Medium |
| Keyword Transposition Cipher | Given a piece of cipher text and the keyword used to encipher it, write an algorithm to output the original message . | Python | Easy |
| Basic Cryptanalysis | Given a piece of text encoded with a simple monoalphabetic substitution cipher, use basic cryptanalytic techniques to attempt to recover the original plain text. | Python | Hard |