Question 1. For decryption to work, the encryption function of the substitution cipher must be     .

	i)	one-one
	ii)	onto
	iii)	constant
	iv)	none of these

Question 2. Which of the following is a primitive root modulo $13$?

	i)	$3$
	ii)	$5$
	iii)	$7$
	iv)	$9$

Question 3. The     has a $2$-to-$1$ message expansion.

	i)	Elgamal PKC
	ii)	RSA PKC
	iii)	Elliptic Elgamal PKC
	iv)	Diffie-Hellman key exchange

Question 4. A square root of $2$ modulo $43$     .

	i)	is $4$
	ii)	is $27$
	iii)	doesn’t exist
	iv)	none of these

Question 5. The solution of $x^5\equiv 3(mod29)$ is     .

	i)	$11$
	ii)	$2$
	iii)	$4$
	iv)	$17$

Question 6. The probability that a randomly chosen number $N$ is prime is     .

	i)	$\frac{1}{\ln <!--FUNCTION\; APPLICATION-->(N)}$
	ii)	$\frac{1}{N}$
	iii)	$\frac{N}{\ln <!--FUNCTION\; APPLICATION-->(N)}$
	iv)	$\frac{\ln <!--FUNCTION\; APPLICATION-->(N)}{N}$

Question 7. The trace of Frobenius for the elliptic curve $E:Y^2=X^3+X+2$ over ${𝔽}_5$ is     .

	i)	$2$
	ii)	$3$
	iii)	$4$
	iv)	$5$

Question 8. Let $E∕{𝔽}_{11}:Y^2=X^3+3$. Then the slope of the tangent line at $(0,5)\in E$ is     .

	i)	$0$
	ii)	$5$
	iii)	$-1$
	iv)	infinite