Question 1. The meaningful plaintext for the Caesar ciphertext “YTIDE” can possibly be     .

	i)	ojyvd
	ii)	today
	iii)	diety
	iv)	tidey

Question 2. The product of all the primitive roots modulo $31$ is     .

	i)	$1$
	ii)	$15$
	iii)	$30$
	iv)	$31$

Question 3. The discrete logarithm problem in ${𝔽}_p$ with addition modulo $p$ is solvable in     time.

	i)	exponential
	ii)	sub-exponential
	iii)	linear
	iv)	quadratic

Question 4. The     is a public-key cryptosystem based on the discrete logarithm problem.

	i)	Diffie-Hellman
	ii)	RSA
	iii)	Elgamal
	iv)	none of these

Question 5. The     test is primality test which does not have Carmichael-like numbers.

	i)	Fermat’s
	ii)	Miller-Rabin’s
	iii)	Pollard’s
	iv)	Shanks’s

Question 6. For a prime $p$ and $e,c\in \mathbb{Z}$, the congruence $x^e\equiv c(modp)$ has a unique solution if     .

	i)	$\gcd <!--FUNCTION\; APPLICATION-->(e,p-1)=1$
	ii)	$\gcd <!--FUNCTION\; APPLICATION-->(e,p)=1$
	iii)	$\gcd <!--FUNCTION\; APPLICATION-->(c,p-1)=1$
	iv)	$\gcd <!--FUNCTION\; APPLICATION-->(c,p)=1$

Question 7. The bound $\#E({𝔽}_p)=p+1-t_p$ with $|t_p|\le 2\sqrt{p}$ is given by     .

	i)	Pollard
	ii)	Miller-Rabin
	iii)	Hasse
	iv)	Frobenius