Diffie Hellman

Question

Answer 1

for diffie hellman n and n-1/2 should be prime

1)107 and 107-1/2=53 both are prime

2)37 is prime but 37-1/2=18 is not prime

3)47  and 47-1/2=23 are prime

4)109  is prime but 109-1/2-54 is not prime

so ans is 1 and 3 ie c

Comments

for diffie hellman n and n-1/2 should be prime , why so ?

---

check this one  D.notes  5th point

http://www.math.ucla.edu/~baker/40/handouts/rev_DH/node1.html

---

@Pooja Palod Please use brackets in the above answer.

---

its n and (n-1)/2

Answer 2

answer = option A

ii and iii cannot be correct as they are close to a perfect square

Comments

Could u explain why so?

N is common chosen prime no here  i suppose

---

Do not have a proof, Today.

---

given answer C