Question

Given public key e=7, n = 35, Plaintext M = 3 in RSA,

i). Find a number d (the decryption key )

ii). Encrypt m using the public key (e , n)

iii).Sign m using the private key (d , n)​

Answer 1

Answer:

To compute the value for d, use the Extended Euclidean Algorithm to calculate d=e−1modϕ, also written d=(1/e)modϕ. This is known as modular inversion . Note that this is not integer division. The modular inverse d is defined as the integer value such that ed=1modϕ.