Inversion

This protocol is executed between the Student Alice (you) and Mentor Bob. Mentor asks you to compute inverse number d to the number e=2^16+1=65537 modulo n.

Parameter values sent by Alice are included in brackets [ ] and must be entered in the corresponding input fields.

The following functions are used in the protocol:

>> randi(2^28)

>> mulinv(e,n)

1. Generate module n of no more than 28 bits length using Octave function >>randi(2^28) and compute prime number e=2^16+1.

Send [n] to the Mentor.

2. Ok, compute multiplicative inverse number d to number e using the following expression >>d=mulinv(e,n) such that d*e=1 mod n. Verify your answer by computing >>mod(d*e) with ans=1 and send [d] to the Mentor.