Working on encryption

src/crypto_system.rs

+use num_bigint::{BigUint};
+use rand::prelude::*
+
+type message = Vec<Bool>;
+type ciphertext = Vec<BigUint>;
+
+pub fn encrypt(message: &message, n: &BigUint, y: &BigUint) {
+    let mut res: ciphertext = Vec<BigUint>::with_capacity(message.len());
+    let mut rng = rand::thread_rng();
+    for i in 0..message.len() {
+        let xi = rand_zn(n);
+        if message[i] {
+            res[i] = y*xi*xi % n;
+        } else {
+            res[i] = xi.modpow(&BigUint::from(2u32), n);
+        }
+    }
+}

src/main.rs

 mod prime_gen;
+use rand::seq::SliceRandom;
 
 fn main() {
-    let p = prime_gen::gen_prime(512);
-    println!("{}", p);
-    println!("{}", p.bits());
+    let mut rng = rand::thread_rng();
+    let p1 = prime_gen::gen_prime(512);
+    let mut p2 = prime_gen::gen_prime(512);
+    while p1 == p2 {
+        p2 = prime_gen::gen_prime(512)
+    }
+    //p1 and p2 are unequal primes (private key)
+    let n = p1*p2; //n is the public key together with some non-residue y to be computed
+    let mut y = astar(n).choose(rng); //astar (vec<bigUInt>) is the coprimes of n with jacobi symbol 1
+    while is_residue(n, y) {
+        //We regenerate y until its not a quadratic residue
+        y = astar(n).choose(rng);
+    }
+    //Now (n, y) is the public key
+    let message = "Hello world".to_string();
+    let cipher = encrypt(&n, &y, &message);
+    
+
 }

src/prime_gen.rs

@@ -40,7 +40,7 @@ fn divides(b: &BigUint, d: u64) -> bool {
     return false;
 }
 
-pub fn divide_small_primes(n: &BigUint) -> bool {
+fn divide_small_primes(n: &BigUint) -> bool {
     let small_primes = erastothenes_sieve(20000);
     for m in small_primes {
         if divides(n, m) {