I'm really lost.
I'm creating a classroom lesson about Rabin encryption and I had understood the encryption process, the creation of public-key (N = p*q) and the steps I need to find the 4 values that can be the solution.
BUT, every sample I find consider the true P and Q to demonstrate the decryption process (Extended Euclidean or Euclidean) and most of them using p=7, q=11, N = 77!
I mean, how they have P and Q?
Is the factoring of N the first step to calculate the secret-key?
Or the solution of trying random values to put into Chinese Remainder Theorem? I can't believe in this because doing so, I would be considering Bob like Eve (have to try a lot of values to get P and Q)!
Can you light my way? I appreciate in advance.