TI2: Cryptography Quiz
The CAESAR encryption works by cyclically shifting all letters by x positions in the alphabet (1 <= x <= 25). For example, with x=3, A becomes D. If you apply CAESAR twice with different x, is it more secure?
To find a large prime easily, you propose the following: You take all primes until some x, multiply them with each other, and subtract 1, resulting in a prime p. You then get another prime p' by p'=(p+1)p-1, which can be iterated. Does this method work?
Alice wants to send a 1 if her answer is yes, and a 0 if her answer is no. To do so, she chooses a one-time pad of one bit as encryption. Is this method malleable?
Malleability can be prevented by hashing the ciphertext, and sending the hash together with the ciphertext.
Submit
This content is neither created nor endorsed by Google. Report Abuse - Terms of Service