ckks: get rid of constant generics (reason in two commits ago)

bfv/src/lib.rs

@@ -16,6 +16,14 @@ use arith::{Ring, Rq, R};
 // sigma=3.2 from: https://eprint.iacr.org/2022/162.pdf page 5
 const ERR_SIGMA: f64 = 3.2;
 
+#[derive(Clone, Copy, Debug)]
+pub struct Params {
+    q: u64,
+    n: usize,
+    t: u64,
+    p: u64,
+}
+
 #[derive(Clone, Debug)]
 pub struct SecretKey(Rq);
 
@@ -92,12 +100,6 @@ impl ops::Add<&Rq> for &RLWE {
     }
 }
 
-pub struct Params {
-    q: u64,
-    n: usize,
-    t: u64,
-    p: u64,
-}
 pub struct BFV {}
 
 impl BFV {

ckks/src/encoder.rs

@@ -3,12 +3,13 @@ use anyhow::Result;
 use arith::{Matrix, Ring, Rq, C, R};
 
 #[derive(Clone, Debug)]
-pub struct SecretKey<const Q: u64, const N: usize>(Rq<Q, N>);
+pub struct SecretKey(Rq);
 
 #[derive(Clone, Debug)]
-pub struct PublicKey<const Q: u64, const N: usize>(Rq<Q, N>, Rq<Q, N>);
+pub struct PublicKey(Rq, Rq);
 
-pub struct Encoder<const Q: u64, const N: usize> {
+pub struct Encoder {
+    n: usize,
     scale_factor: C<f64>, // Δ (delta)
     primitive: C<f64>,
     basis: Matrix<C<f64>>,
@@ -34,13 +35,14 @@ fn vandermonde(n: usize, w: C) -> Matrix> {
     }
     Matrix::<C<f64>>(v)
 }
-impl<const Q: u64, const N: usize> Encoder<Q, N> {
-    pub fn new(scale_factor: C<f64>) -> Self {
-        let primitive: C<f64> = primitive_root_of_unity(2 * N);
-        let basis = vandermonde(N, primitive);
+impl Encoder {
+    pub fn new(n: usize, scale_factor: C<f64>) -> Self {
+        let primitive: C<f64> = primitive_root_of_unity(2 * n);
+        let basis = vandermonde(n, primitive);
         let basis_t = basis.transpose();
 
         Self {
+            n,
             scale_factor,
             primitive,
             basis,
@@ -52,7 +54,7 @@ impl Encoder {
     /// from $\mathbb{C}^{N/2} \longrightarrow \mathbb{Z_q}[X]/(X^N +1) = R$
     // TODO use alg.1 from 2018-1043,
     //      or as in 2018-1073: $f(x) = 1N (U^T.conj() m + U^T m.conj())$
-    pub fn encode(&self, z: &[C<f64>]) -> Result<R<N>> {
+    pub fn encode(&self, z: &[C<f64>]) -> Result<R> {
         // $pi^{-1}: \mathbb{C}^{N/2} \longrightarrow \mathbb{H}$
         let expanded = self.pi_inv(z);
 
@@ -93,10 +95,10 @@ impl Encoder {
 
         // TMP: naive round, maybe do gaussian
         let coeffs = r.iter().map(|e| e.re.round() as i64).collect::<Vec<i64>>();
-        Ok(R::from_vec(coeffs))
+        Ok(R::from_vec(self.n, coeffs))
     }
 
-    pub fn decode(&self, p: &R<N>) -> Result<Vec<C<f64>>> {
+    pub fn decode(&self, p: &R) -> Result<Vec<C<f64>>> {
         let p: Vec<C<f64>> = p
             .coeffs()
             .iter()
@@ -110,7 +112,7 @@ impl Encoder {
 
     /// pi: \mathbb{H} \longrightarrow \mathbb{C}^{N/2}
     fn pi(&self, z: &[C<f64>]) -> Vec<C<f64>> {
-        z[..N / 2].to_vec()
+        z[..self.n / 2].to_vec()
     }
     /// pi^{-1}: \mathbb{C}^{N/2} \longrightarrow \mathbb{H}
     fn pi_inv(&self, z: &[C<f64>]) -> Vec<C<f64>> {
@@ -154,6 +156,7 @@ mod tests {
     fn test_encode_decode() -> Result<()> {
         const Q: u64 = 1024;
         const N: usize = 32;
+        let n: usize = 32;
 
         let T = 128; // WIP
         let mut rng = rand::thread_rng();
@@ -166,9 +169,9 @@ mod tests {
             .collect();
 
             let delta = C::<f64>::new(64.0, 0.0); // delta = scaling factor
-            let encoder = Encoder::<Q, N>::new(delta);
+            let encoder = Encoder::new(n, delta);
 
-            let m: R<N> = encoder.encode(&z)?; // polynomial (encoded vec) \in R
+            let m: R = encoder.encode(&z)?; // polynomial (encoded vec) \in R
 
             let z_decoded = encoder.decode(&m)?;
 

ckks/src/lib.rs

@@ -18,35 +18,48 @@ pub use encoder::Encoder;
 // sigma=3.2 from: https://eprint.iacr.org/2016/421.pdf page 17
 const ERR_SIGMA: f64 = 3.2;
 
+#[derive(Clone, Copy, Debug)]
+pub struct Params {
+    q: u64,
+    n: usize,
+    t: u64,
+}
+
 #[derive(Debug)]
-pub struct PublicKey<const Q: u64, const N: usize>(Rq<Q, N>, Rq<Q, N>);
+pub struct PublicKey(Rq, Rq);
 
-pub struct SecretKey<const Q: u64, const N: usize>(Rq<Q, N>);
+pub struct SecretKey(Rq);
 
-pub struct CKKS<const Q: u64, const N: usize> {
-    encoder: Encoder<Q, N>,
+pub struct CKKS {
+    params: Params,
+    encoder: Encoder,
 }
 
-impl<const Q: u64, const N: usize> CKKS<Q, N> {
-    pub fn new(delta: C<f64>) -> Self {
-        let encoder = Encoder::<Q, N>::new(delta);
-        Self { encoder }
+impl CKKS {
+    pub fn new(params: &Params, delta: C<f64>) -> Self {
+        let encoder = Encoder::new(params.n, delta);
+        Self {
+            params: params.clone(),
+            encoder,
+        }
     }
     /// generate a new key pair (privK, pubK)
-    pub fn new_key(&self, mut rng: impl Rng) -> Result<(SecretKey<Q, N>, PublicKey<Q, N>)> {
+    pub fn new_key(&self, mut rng: impl Rng) -> Result<(SecretKey, PublicKey)> {
+        let params = &self.params;
+
         let Xi_key = Uniform::new(-1_f64, 1_f64);
         let Xi_err = Normal::new(0_f64, ERR_SIGMA)?;
 
-        let e = Rq::<Q, N>::rand_f64(&mut rng, Xi_err)?;
+        let e = Rq::rand_f64(&mut rng, Xi_err, params.q, params.n)?;
 
-        let mut s = Rq::<Q, N>::rand_f64(&mut rng, Xi_key)?;
+        let mut s = Rq::rand_f64(&mut rng, Xi_key, params.q, params.n)?;
         // since s is going to be multiplied by other Rq elements, already
         // compute its NTT
         s.compute_evals();
 
-        let a = Rq::<Q, N>::rand_f64(&mut rng, Xi_key)?;
+        let a = Rq::rand_f64(&mut rng, Xi_key, params.q, params.n)?;
 
-        let pk: PublicKey<Q, N> = PublicKey((&(-a) * &s) + e, a.clone());
+        let pk: PublicKey = PublicKey((&(-a.clone()) * &s) + e, a.clone()); // TODO rm clones
         Ok((SecretKey(s), pk))
     }
 
@@ -54,64 +67,54 @@ impl CKKS {
     fn encrypt(
         &self, // TODO maybe rm?
         mut rng: impl Rng,
-        pk: &PublicKey<Q, N>,
-        m: &R<N>,
-    ) -> Result<(Rq<Q, N>, Rq<Q, N>)> {
+        pk: &PublicKey,
+        m: &R,
+    ) -> Result<(Rq, Rq)> {
+        let params = self.params;
         let Xi_key = Uniform::new(-1_f64, 1_f64);
         let Xi_err = Normal::new(0_f64, ERR_SIGMA)?;
 
-        let e_0 = Rq::<Q, N>::rand_f64(&mut rng, Xi_err)?;
-        let e_1 = Rq::<Q, N>::rand_f64(&mut rng, Xi_err)?;
+        let e_0 = Rq::rand_f64(&mut rng, Xi_err, params.q, params.n)?;
+        let e_1 = Rq::rand_f64(&mut rng, Xi_err, params.q, params.n)?;
 
-        let v = Rq::<Q, N>::rand_f64(&mut rng, Xi_key)?;
+        let v = Rq::rand_f64(&mut rng, Xi_key, params.q, params.n)?;
 
-        let m: Rq<Q, N> = Rq::<Q, N>::from(*m);
+        // let m: Rq = Rq::from(*m);
+        let m: Rq = m.clone().to_rq(params.q); // TODO rm clone
 
-        Ok((m + e_0 + v * pk.0.clone(), v * pk.1.clone() + e_1))
+        Ok((m + e_0 + &v * &pk.0.clone(), &v * &pk.1 + e_1))
     }
 
     fn decrypt(
         &self, // TODO maybe rm?
-        sk: &SecretKey<Q, N>,
-        c: (Rq<Q, N>, Rq<Q, N>),
-    ) -> Result<R<N>> {
-        let m = c.0.clone() + c.1 * sk.0;
+        sk: &SecretKey,
+        c: (Rq, Rq),
+    ) -> Result<R> {
+        let m = c.0.clone() + &c.1 * &sk.0;
         Ok(m.mod_centered_q())
     }
 
     pub fn encode_and_encrypt(
         &self,
         mut rng: impl Rng,
-        pk: &PublicKey<Q, N>,
+        pk: &PublicKey,
         z: &[C<f64>],
-    ) -> Result<(Rq<Q, N>, Rq<Q, N>)> {
-        let m: R<N> = self.encoder.encode(&z)?; // polynomial (encoded vec) \in R
+    ) -> Result<(Rq, Rq)> {
+        let m: R = self.encoder.encode(&z)?; // polynomial (encoded vec) \in R
 
         self.encrypt(&mut rng, pk, &m)
     }
 
-    pub fn decrypt_and_decode(
-        &self,
-        sk: SecretKey<Q, N>,
-        c: (Rq<Q, N>, Rq<Q, N>),
-    ) -> Result<Vec<C<f64>>> {
+    pub fn decrypt_and_decode(&self, sk: SecretKey, c: (Rq, Rq)) -> Result<Vec<C<f64>>> {
         let d = self.decrypt(&sk, c)?;
 
         self.encoder.decode(&d)
     }
 
-    pub fn add(
-        &self,
-        c0: &(Rq<Q, N>, Rq<Q, N>),
-        c1: &(Rq<Q, N>, Rq<Q, N>),
-    ) -> Result<(Rq<Q, N>, Rq<Q, N>)> {
+    pub fn add(&self, c0: &(Rq, Rq), c1: &(Rq, Rq)) -> Result<(Rq, Rq)> {
         Ok((&c0.0 + &c1.0, &c0.1 + &c1.1))
     }
-    pub fn sub(
-        &self,
-        c0: &(Rq<Q, N>, Rq<Q, N>),
-        c1: &(Rq<Q, N>, Rq<Q, N>),
-    ) -> Result<(Rq<Q, N>, Rq<Q, N>)> {
+    pub fn sub(&self, c0: &(Rq, Rq), c1: &(Rq, Rq)) -> Result<(Rq, Rq)> {
         Ok((&c0.0 - &c1.0, &c0.1 + &c1.1))
     }
 }
@@ -122,21 +125,22 @@ mod tests {
 
     #[test]
     fn test_encrypt_decrypt() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 32;
-        const T: u64 = 50;
+        let q: u64 = 2u64.pow(16) + 1;
+        let n: usize = 32;
+        let t: u64 = 50;
+        let params = Params { q, n, t };
         let scale_factor_u64 = 512_u64; // delta
         let scale_factor = C::<f64>::new(scale_factor_u64 as f64, 0.0); // delta
 
         let mut rng = rand::thread_rng();
 
         for _ in 0..1000 {
-            let ckks = CKKS::<Q, N>::new(scale_factor);
+            let ckks = CKKS::new(&params, scale_factor);
 
             let (sk, pk) = ckks.new_key(&mut rng)?;
 
-            let m_raw: R<N> = Rq::<Q, N>::rand_f64(&mut rng, Uniform::new(0_f64, T as f64))?.to_r();
-            let m = m_raw * scale_factor_u64;
+            let m_raw: R = Rq::rand_f64(&mut rng, Uniform::new(0_f64, t as f64), q, n)?.to_r();
+            let m = &m_raw * &scale_factor_u64;
 
             let ct = ckks.encrypt(&mut rng, &pk, &m)?;
             let m_decrypted = ckks.decrypt(&sk, ct)?;
@@ -146,8 +150,9 @@ mod tests {
                 .iter()
                 .map(|e| (*e as f64 / (scale_factor_u64 as f64)).round() as u64)
                 .collect();
-            let m_decrypted = Rq::<Q, N>::from_vec_u64(m_decrypted);
-            assert_eq!(m_decrypted, Rq::<Q, N>::from(m_raw));
+            let m_decrypted = Rq::from_vec_u64(q, n, m_decrypted);
+            // assert_eq!(m_decrypted, Rq::from(m_raw));
+            assert_eq!(m_decrypted, m_raw.to_rq(q));
         }
 
         Ok(())
@@ -155,21 +160,22 @@ mod tests {
 
     #[test]
     fn test_encode_encrypt_decrypt_decode() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 16;
-        const T: u64 = 8;
+        let q: u64 = 2u64.pow(16) + 1;
+        let n: usize = 16;
+        let t: u64 = 8;
+        let params = Params { q, n, t };
         let scale_factor = C::<f64>::new(512.0, 0.0); // delta
 
         let mut rng = rand::thread_rng();
 
         for _ in 0..1000 {
-            let ckks = CKKS::<Q, N>::new(scale_factor);
+            let ckks = CKKS::new(&params, scale_factor);
             let (sk, pk) = ckks.new_key(&mut rng)?;
 
-            let z: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, T))
-                .take(N / 2)
+            let z: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, t))
+                .take(n / 2)
                 .collect();
-            let m: R<N> = ckks.encoder.encode(&z)?;
+            let m: R = ckks.encoder.encode(&z)?;
             println!("{}", m);
 
             // sanity check
@@ -200,26 +206,27 @@ mod tests {
 
     #[test]
     fn test_add() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 16;
-        const T: u64 = 8;
+        let q: u64 = 2u64.pow(16) + 1;
+        let n: usize = 16;
+        let t: u64 = 8;
+        let params = Params { q, n, t };
         let scale_factor = C::<f64>::new(1024.0, 0.0); // delta
 
         let mut rng = rand::thread_rng();
 
         for _ in 0..1000 {
-            let ckks = CKKS::<Q, N>::new(scale_factor);
+            let ckks = CKKS::new(&params, scale_factor);
 
             let (sk, pk) = ckks.new_key(&mut rng)?;
 
-            let z0: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, T))
-                .take(N / 2)
+            let z0: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, t))
+                .take(n / 2)
                 .collect();
-            let z1: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, T))
-                .take(N / 2)
+            let z1: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, t))
+                .take(n / 2)
                 .collect();
-            let m0: R<N> = ckks.encoder.encode(&z0)?;
-            let m1: R<N> = ckks.encoder.encode(&z1)?;
+            let m0: R = ckks.encoder.encode(&z0)?;
+            let m1: R = ckks.encoder.encode(&z1)?;
 
             let ct0 = ckks.encrypt(&mut rng, &pk, &m0)?;
             let ct1 = ckks.encrypt(&mut rng, &pk, &m1)?;
@@ -243,26 +250,27 @@ mod tests {
 
     #[test]
     fn test_sub() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 16;
-        const T: u64 = 8;
+        let q: u64 = 2u64.pow(16) + 1;
+        let n: usize = 16;
+        let t: u64 = 8;
+        let params = Params { q, n, t };
         let scale_factor = C::<f64>::new(1024.0, 0.0); // delta
 
         let mut rng = rand::thread_rng();
 
         for _ in 0..1000 {
-            let ckks = CKKS::<Q, N>::new(scale_factor);
+            let ckks = CKKS::new(&params, scale_factor);
 
             let (sk, pk) = ckks.new_key(&mut rng)?;
 
-            let z0: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, T))
-                .take(N / 2)
+            let z0: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, t))
+                .take(n / 2)
                 .collect();
-            let z1: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, T))
-                .take(N / 2)
+            let z1: Vec<C<f64>> = std::iter::repeat_with(|| C::<f64>::rand(&mut rng, t))
+                .take(n / 2)
                 .collect();
-            let m0: R<N> = ckks.encoder.encode(&z0)?;
-            let m1: R<N> = ckks.encoder.encode(&z1)?;
+            let m0: R = ckks.encoder.encode(&z0)?;
+            let m1: R = ckks.encoder.encode(&z1)?;
 
             let ct0 = ckks.encrypt(&mut rng, &pk, &m0)?;
             let ct1 = ckks.encrypt(&mut rng, &pk, &m1)?;