fhe-study · arnaucube's git mirror

gfhe: get rid of constant generics

arnaucube git@arnaucube.com

Tue, 12 Aug 2025 17:10:20 +0000

commit

2a9cbc71dec629a1c9ac2288a1a435b255393635

parent

9e90f094a9cb82401cb58378edca4f4aff1c425a

7 files changed, 437 insertions(+), 283 deletions(-)

jump to

arith/src/lib.rs

arith/src/ntt.rs

arith/src/ring_torus.rs

arith/src/torus.rs

arith/src/tuple_ring.rs

gfhe/src/glev.rs

gfhe/src/glwe.rs

M arith/src/lib.rs → arith/src/lib.rs

@@ -6,14 +6,14 @@ #![allow(dead_code)] // TMP
 
 pub mod complex;
 pub mod matrix;
-// pub mod torus;
+pub mod torus;
 pub mod zq;
 
 pub mod ring;
 pub mod ring_n;
 pub mod ring_nq;
-// pub mod ring_torus;
-// pub mod tuple_ring;
+pub mod ring_torus;
+pub mod tuple_ring;
 
 // mod naive_ntt; // note: for dev only
 pub mod ntt;
@@ -22,13 +22,13 @@ // expose objects
 
 pub use complex::C;
 pub use matrix::Matrix;
-// pub use torus::T64;
+pub use torus::T64;
 pub use zq::Zq;
 
 pub use ring::{Ring, RingParam};
 pub use ring_n::R;
 pub use ring_nq::Rq;
-// pub use ring_torus::Tn;
-// pub use tuple_ring::TR;
+pub use ring_torus::Tn;
+pub use tuple_ring::TR;
 
 pub use ntt::NTT;

M arith/src/ntt.rs → arith/src/ntt.rs

@@ -241,4 +241,27 @@ assert_eq!(a, a_intt);
         }
         Ok(())
     }
+
+    // #[test]
+    // fn test_ntt_loop_2() -> Result<()> {
+    //     // let q: u64 = 2u64.pow(16) + 1;
+    //     // let n: usize = 512;
+    //     let q: u64 = 35184371138561;
+    //     let n: usize = 1 << 14;
+    //     let param = RingParam { q, n };
+    //
+    //     use rand::distributions::Uniform;
+    //     let mut rng = rand::thread_rng();
+    //     let dist = Uniform::new(0_f64, q as f64);
+    //
+    //     let a: Rq = Rq::rand(&mut rng, dist, &param);
+    //     let start = std::time::Instant::now();
+    //     for _ in 0..10_000 {
+    //         let a_ntt = NTT::ntt(&a);
+    //         let a_intt = NTT::intt(&a_ntt);
+    //         assert_eq!(a, a_intt);
+    //     }
+    //     dbg!(start.elapsed());
+    //     Ok(())
+    // }
 }

M arith/src/ring_torus.rs → arith/src/ring_torus.rs

@@ -13,51 +13,62 @@ use std::array;
 use std::iter::Sum;
 use std::ops::{Add, AddAssign, Mul, Neg, Sub, SubAssign};
 
-use crate::{ring::Ring, torus::T64, Rq, Zq};
+use crate::{
+    ring::{Ring, RingParam},
+    torus::T64,
+    Rq, Zq,
+};
 
 /// 𝕋_<N,Q>[X] = 𝕋<Q>[X]/(X^N +1), polynomials modulo X^N+1 with coefficients in
 /// 𝕋, where Q=2^64.
 #[derive(Clone, Debug)]
 pub struct Tn {
-    pub n: usize,
+    // pub n: usize,
+    pub param: RingParam,
     pub coeffs: Vec<T64>,
 }
 
 impl Ring for Tn {
     type C = T64;
-    type Param = usize; // n
+    // type Param = usize; // n
 
     // const Q: u64 = u64::MAX; // WIP
     // const N: usize = N;
 
-    fn param(&self) -> Self::Param {
-        self.n
+    fn param(&self) -> RingParam {
+        RingParam {
+            q: u64::MAX,
+            n: self.param.n,
+        }
     }
     fn coeffs(&self) -> Vec<T64> {
         self.coeffs.to_vec()
     }
 
-    fn zero(n: usize) -> Self {
+    fn zero(param: &RingParam) -> Self {
         Self {
-            n,
-            coeffs: vec![T64::zero(()); n],
+            param: *param,
+            coeffs: vec![T64::zero(param); param.n],
         }
     }
 
-    fn rand(mut rng: impl Rng, dist: impl Distribution<f64>, n: usize) -> Self {
+    fn rand(mut rng: impl Rng, dist: impl Distribution<f64>, param: &RingParam) -> Self {
         Self {
-            n,
-            coeffs: std::iter::repeat_with(|| T64::rand(&mut rng, &dist, ()))
-                .take(n)
+            param: *param,
+            coeffs: std::iter::repeat_with(|| T64::rand(&mut rng, &dist, &param))
+                .take(param.n)
                 .collect(),
         }
         // Self(array::from_fn(|_| T64::rand(&mut rng, &dist)))
     }
 
-    fn from_vec(n: usize, coeffs: Vec<Self::C>) -> Self {
+    fn from_vec(param: &RingParam, coeffs: Vec<Self::C>) -> Self {
         let mut p = coeffs;
-        modulus(n, &mut p);
-        Self { n, coeffs: p }
+        modulus(param, &mut p);
+        Self {
+            param: *param,
+            coeffs: p,
+        }
     }
 
     fn decompose(&self, beta: u32, l: u32) -> Vec<Self> {
@@ -68,7 +79,7 @@ .map(|i| (0..elems.len()).map(|j| elems[j][i]).collect())
             .collect();
         // convert it to Tn
         r.iter()
-            .map(|a_i| Self::from_vec(self.n, a_i.clone()))
+            .map(|a_i| Self::from_vec(&self.param, a_i.clone()))
             .collect()
     }
 
@@ -87,8 +98,10 @@ .iter()
             .map(|c_i| Zq::from_u64(p, c_i.mod_switch(p).0))
             .collect();
         Rq {
-            q: p,
-            n: self.n,
+            param: RingParam {
+                q: p,
+                n: self.param.n,
+            },
             coeffs,
             evals: None,
         }
@@ -103,14 +116,14 @@ .coeffs()
             .iter()
             .map(|e| T64(((num as f64 * e.0 as f64) / den as f64).round() as u64))
             .collect();
-        Self::from_vec(self.n, r)
+        Self::from_vec(&self.param, r)
     }
 }
 
 impl Tn {
     // multiply self by X^-h
     pub fn left_rotate(&self, h: usize) -> Self {
-        let n = self.n;
+        let n = self.param.n;
 
         let h = h % n;
         assert!(h < n);
@@ -122,23 +135,24 @@ .iter()
             .copied()
             .chain(c[0..h].iter().map(|&x| -x))
             .collect();
-        Self::from_vec(self.n, r)
+        Self::from_vec(&self.param, r)
     }
 
-    pub fn from_vec_u64(n: usize, v: Vec<u64>) -> Self {
+    pub fn from_vec_u64(param: &RingParam, v: Vec<u64>) -> Self {
         let coeffs = v.iter().map(|c| T64(*c)).collect();
-        Self::from_vec(n, coeffs)
+        Self::from_vec(param, coeffs)
     }
 }
 
 // apply mod (X^N+1)
-pub fn modulus(n: usize, p: &mut Vec<T64>) {
+pub fn modulus(param: &RingParam, p: &mut Vec<T64>) {
+    let n = param.n;
     if p.len() < n {
         return;
     }
     for i in n..p.len() {
         p[i - n] = p[i - n].clone() - p[i].clone();
-        p[i] = T64::zero(());
+        p[i] = T64::zero(param);
     }
     p.truncate(n);
 }
@@ -148,9 +162,9 @@ type Output = Self;
 
     fn add(self, rhs: Self) -> Self {
         // Self(array::from_fn(|i| self.0[i] + rhs.0[i]))
-        assert_eq!(self.n, rhs.n);
+        assert_eq!(self.param, rhs.param);
         Self {
-            n: self.n,
+            param: self.param,
             coeffs: zip_eq(self.coeffs, rhs.coeffs)
                 .map(|(l, r)| l + r)
                 .collect(),
@@ -162,9 +176,9 @@ type Output = Tn;
 
     fn add(self, rhs: &Tn) -> Self::Output {
         // Tn(array::from_fn(|i| self.0[i] + rhs.0[i]))
-        assert_eq!(self.n, rhs.n);
+        assert_eq!(self.param, rhs.param);
         Tn {
-            n: self.n,
+            param: self.param,
             coeffs: zip_eq(self.coeffs.clone(), rhs.coeffs.clone())
                 .map(|(l, r)| l + r)
                 .collect(),
@@ -173,15 +187,15 @@ }
 }
 impl AddAssign for Tn {
     fn add_assign(&mut self, rhs: Self) {
-        assert_eq!(self.n, rhs.n);
-        for i in 0..self.n {
+        assert_eq!(self.param, rhs.param);
+        for i in 0..self.param.n {
             self.coeffs[i] += rhs.coeffs[i];
         }
     }
 }
 
 impl Sum<Tn> for Tn {
-    fn sum<I>(iter: I) -> Self
+    fn sum<I>(mut iter: I) -> Self
     where
         I: Iterator<Item = Self>,
     {
@@ -190,7 +204,7 @@ // for e in iter {
         //     acc += e;
         // }
         // acc
-        let first = *iter.next().unwrap().borrow();
+        let first = iter.next().unwrap();
         iter.fold(first, |acc, x| acc + x)
     }
 }
@@ -199,9 +213,9 @@ impl Sub<Tn> for Tn {
     type Output = Self;
 
     fn sub(self, rhs: Self) -> Self {
-        assert_eq!(self.n, rhs.n);
+        assert_eq!(self.param, rhs.param);
         Self {
-            n: self.n,
+            param: self.param,
             coeffs: zip_eq(self.coeffs, rhs.coeffs)
                 .map(|(l, r)| l - r)
                 .collect(),
@@ -213,9 +227,9 @@ type Output = Tn;
 
     fn sub(self, rhs: &Tn) -> Self::Output {
         // Tn(array::from_fn(|i| self.0[i] - rhs.0[i]))
-        assert_eq!(self.n, rhs.n);
+        assert_eq!(self.param, rhs.param);
         Tn {
-            n: self.n,
+            param: self.param,
             coeffs: zip_eq(self.coeffs.clone(), rhs.coeffs.clone())
                 .map(|(l, r)| l - r)
                 .collect(),
@@ -228,8 +242,8 @@ fn sub_assign(&mut self, rhs: Self) {
         // for i in 0..N {
         //     self.0[i] -= rhs.0[i];
         // }
-        assert_eq!(self.n, rhs.n);
-        for i in 0..self.n {
+        assert_eq!(self.param, rhs.param);
+        for i in 0..self.param.n {
             self.coeffs[i] -= rhs.coeffs[i];
         }
     }
@@ -241,7 +255,7 @@
     fn neg(self) -> Self::Output {
         // Tn(array::from_fn(|i| -self.0[i]))
         Self {
-            n: self.n,
+            param: self.param,
             coeffs: self.coeffs.iter().map(|c_i| -*c_i).collect(),
         }
     }
@@ -249,7 +263,7 @@ }
 
 impl PartialEq for Tn {
     fn eq(&self, other: &Self) -> bool {
-        self.coeffs == other.coeffs && self.n == other.n
+        self.coeffs == other.coeffs && self.param == other.param
     }
 }
 
@@ -269,8 +283,9 @@ }
 }
 
 fn naive_poly_mul(poly1: &Tn, poly2: &Tn) -> Tn {
-    assert_eq!(poly1.n, poly2.n);
-    let n = poly1.n;
+    assert_eq!(poly1.param, poly2.param);
+    let n = poly1.param.n;
+    let param = poly1.param;
 
     let poly1: Vec<u128> = poly1.coeffs.iter().map(|c| c.0 as u128).collect();
     let poly2: Vec<u128> = poly2.coeffs.iter().map(|c| c.0 as u128).collect();
@@ -285,7 +300,7 @@ // apply mod (X^n + 1))
     modulus_u128(n, &mut result);
 
     Tn {
-        n,
+        param,
         // coeffs: array::from_fn(|i| T64(result[i] as u64)),
         coeffs: result.iter().map(|r_i| T64(*r_i as u64)).collect(),
     }
@@ -306,7 +321,7 @@ impl Mul<T64> for Tn {
     type Output = Self;
     fn mul(self, s: T64) -> Self {
         Self {
-            n: self.n,
+            param: self.param,
             // coeffs: array::from_fn(|i| self.coeffs[i] * s),
             coeffs: self.coeffs.iter().map(|c_i| *c_i * s).collect(),
         }
@@ -318,7 +333,7 @@ type Output = Self;
     fn mul(self, s: u64) -> Self {
         // Self(array::from_fn(|i| self.0[i] * s))
         Tn {
-            n: self.n,
+            param: self.param,
             coeffs: self.coeffs.iter().map(|c_i| *c_i * s).collect(),
         }
     }
@@ -327,8 +342,8 @@ impl Mul<&u64> for &Tn {
     type Output = Tn;
     fn mul(self, s: &u64) -> Self::Output {
         // Tn::<N>(array::from_fn(|i| self.0[i] * *s))
-        Self {
-            n: self.n,
+        Tn {
+            param: self.param,
             coeffs: self.coeffs.iter().map(|c_i| c_i * s).collect(),
         }
     }
@@ -340,9 +355,9 @@ use super::*;
 
     #[test]
     fn test_left_rotate() {
-        let n: usize = 4;
+        let param = RingParam { q: u64::MAX, n: 4 };
         let f = Tn::from_vec(
-            n,
+            &param,
             vec![2i64, 3, -4, -1]
                 .iter()
                 .map(|c| T64(*c as u64))
@@ -353,7 +368,7 @@ // expect f*x^-3 == -1 -2x -3x^2 +4x^3
         assert_eq!(
             f.left_rotate(3),
             Tn::from_vec(
-                n,
+                &param,
                 vec![-1i64, -2, -3, 4]
                     .iter()
                     .map(|c| T64(*c as u64))
@@ -364,7 +379,7 @@ // expect f*x^-1 == 3 -4x -1x^2 -2x^3
         assert_eq!(
             f.left_rotate(1),
             Tn::from_vec(
-                n,
+                &param,
                 vec![3i64, -4, -1, -2]
                     .iter()
                     .map(|c| T64(*c as u64))

M arith/src/torus.rs → arith/src/torus.rs

@@ -4,7 +4,7 @@ iter::Sum,
     ops::{Add, AddAssign, Mul, MulAssign, Neg, Sub, SubAssign},
 };
 
-use crate::ring::Ring;
+use crate::ring::{Ring, RingParam};
 
 /// Let 𝕋 = ℝ/ℤ, where 𝕋 is a ℤ-module, with homogeneous external product.
 /// Let 𝕋q
@@ -21,20 +21,23 @@
     // const Q: u64 = u64::MAX; // WIP
     // const N: usize = 1;
 
-    fn param(&self) -> Self::Param {
-        ()
+    fn param(&self) -> RingParam {
+        RingParam {
+            q: u64::MAX, // WIP
+            n: 1,
+        }
     }
     fn coeffs(&self) -> Vec<T64> {
         vec![self.clone()]
     }
-    fn zero(_: ()) -> Self {
+    fn zero(_: &RingParam) -> Self {
         Self(0u64)
     }
-    fn rand(mut rng: impl Rng, dist: impl Distribution<f64>, _: ()) -> Self {
+    fn rand(mut rng: impl Rng, dist: impl Distribution<f64>, _: &RingParam) -> Self {
         let r: f64 = dist.sample(&mut rng);
         Self(r.round() as u64)
     }
-    fn from_vec(_n: (), coeffs: Vec<Self::C>) -> Self {
+    fn from_vec(_n: &RingParam, coeffs: Vec<Self::C>) -> Self {
         assert_eq!(coeffs.len(), 1);
         coeffs[0]
     }
@@ -178,9 +181,13 @@ let x = T64(u64::MAX - 1);
         let d = x.decompose(beta, l);
         assert_eq!(recompose(d), T64(u64::MAX - 1));
 
+        let param = RingParam {
+            q: u64::MAX, // WIP
+            n: 1,
+        };
         let mut rng = rand::thread_rng();
         for _ in 0..1000 {
-            let x = T64::rand(&mut rng, Standard, ());
+            let x = T64::rand(&mut rng, Standard, &param);
             let d = x.decompose(beta, l);
             assert_eq!(recompose(d), x);
         }

M arith/src/tuple_ring.rs → arith/src/tuple_ring.rs

@@ -113,7 +113,7 @@
     fn neg(self) -> Self::Output {
         Self {
             k: self.k,
-            r: self.r.iter().map(|e_i| -*e_i).collect(),
+            r: self.r.iter().map(|e_i| -e_i.clone()).collect(),
         }
     }
 }

M gfhe/src/glev.rs → gfhe/src/glev.rs

@@ -6,23 +6,29 @@ use std::ops::{Add, Mul};
 
 use arith::{Ring, TR};
 
-use crate::glwe::{PublicKey, SecretKey, GLWE};
+use crate::glwe::{Param, PublicKey, SecretKey, GLWE};
 
 // l GLWEs
 #[derive(Clone, Debug)]
-pub struct GLev<R: Ring, const K: usize>(pub(crate) Vec<GLWE<R, K>>);
+pub struct GLev<R: Ring>(pub(crate) Vec<GLWE<R>>);
 
-impl<R: Ring, const K: usize> GLev<R, K> {
+impl<R: Ring> GLev<R> {
     pub fn encrypt(
         mut rng: impl Rng,
+        param: &Param,
         beta: u32,
         l: u32,
-        pk: &PublicKey<R, K>,
+        pk: &PublicKey<R>,
         m: &R,
     ) -> Result<Self> {
-        let glev: Vec<GLWE<R, K>> = (0..l)
+        let glev: Vec<GLWE<R>> = (0..l)
             .map(|i| {
-                GLWE::<R, K>::encrypt(&mut rng, pk, &(*m * (R::Q / beta.pow(i as u32) as u64)))
+                GLWE::<R>::encrypt(
+                    &mut rng,
+                    param,
+                    pk,
+                    &(m.clone() * (param.ring.q / beta.pow(i as u32) as u64)),
+                )
             })
             .collect::<Result<Vec<_>>>()?;
 
@@ -30,38 +36,46 @@ Ok(Self(glev))
     }
     pub fn encrypt_s(
         mut rng: impl Rng,
+        param: &Param,
         beta: u32,
         l: u32,
-        sk: &SecretKey<R, K>,
+        sk: &SecretKey<R>,
         m: &R,
         // delta: u64,
     ) -> Result<Self> {
-        let glev: Vec<GLWE<R, K>> = (1..l + 1)
+        let glev: Vec<GLWE<R>> = (1..l + 1)
             .map(|i| {
-                GLWE::<R, K>::encrypt_s(&mut rng, sk, &(*m * (R::Q / beta.pow(i as u32) as u64)))
+                GLWE::<R>::encrypt_s(
+                    &mut rng,
+                    param,
+                    sk,
+                    &(m.clone() * (param.ring.q / beta.pow(i as u32) as u64)), // TODO rm clone
+                )
             })
             .collect::<Result<Vec<_>>>()?;
 
         Ok(Self(glev))
     }
 
-    pub fn decrypt<const T: u64>(&self, sk: &SecretKey<R, K>, beta: u32) -> R {
+    pub fn decrypt(&self, param: &Param, sk: &SecretKey<R>, beta: u32) -> R {
         let pt = self.0[1].decrypt(sk);
-        pt.mul_div_round(beta as u64, R::Q)
+        pt.mul_div_round(beta as u64, param.ring.q)
     }
 }
 
 // dot product between a GLev and Vec<R>.
 // Used for operating decompositions with KSK_i.
 // GLev * Vec<R> --> GLWE
-impl<R: Ring, const K: usize> Mul<Vec<R>> for GLev<R, K> {
-    type Output = GLWE<R, K>;
-    fn mul(self, v: Vec<R>) -> GLWE<R, K> {
+impl<R: Ring> Mul<Vec<R>> for GLev<R> {
+    type Output = GLWE<R>;
+    fn mul(self, v: Vec<R>) -> GLWE<R> {
+        // TODO debug_assert_eq of params
+
         // l times GLWES
-        let glwes: Vec<GLWE<R, K>> = self.0;
+        let glwes: Vec<GLWE<R>> = self.0;
 
         // l iterations
-        let r: GLWE<R, K> = zip_eq(v, glwes).map(|(v_i, glwe_i)| glwe_i * v_i).sum();
+        let r: GLWE<R> = zip_eq(v, glwes).map(|(v_i, glwe_i)| glwe_i * v_i).sum();
         r
     }
 }
@@ -72,33 +86,37 @@ use anyhow::Result;
     use rand::distributions::Uniform;
 
     use super::*;
-    use arith::Rq;
+    use arith::{RingParam, Rq};
 
     #[test]
     fn test_encrypt_decrypt() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 128;
-        const T: u64 = 2; // plaintext modulus
-        const K: usize = 16;
-        type S = GLev<Rq<Q, N>, K>;
+        let param = Param {
+            ring: RingParam {
+                q: 2u64.pow(16) + 1,
+                n: 128,
+            },
+            k: 16,
+            t: 2, // plaintext modulus
+        };
+        type S = GLev<Rq>;
 
         let beta: u32 = 2;
         let l: u32 = 16;
 
         // let delta: u64 = Q / T; // floored
         let mut rng = rand::thread_rng();
-        let msg_dist = Uniform::new(0_u64, T);
+        let msg_dist = Uniform::new(0_u64, param.t);
 
         for _ in 0..200 {
-            let (sk, pk) = GLWE::<Rq<Q, N>, K>::new_key(&mut rng)?;
+            let (sk, pk) = GLWE::<Rq>::new_key(&mut rng, &param)?;
 
-            let m = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
-            let m: Rq<Q, N> = m.remodule::<Q>();
+            let m = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
+            let m: Rq = m.remodule(param.ring.q);
 
-            let c = S::encrypt(&mut rng, beta, l, &pk, &m)?;
-            let m_recovered = c.decrypt::<T>(&sk, beta);
+            let c = S::encrypt(&mut rng, &param, beta, l, &pk, &m)?;
+            let m_recovered = c.decrypt(&param, &sk, beta);
 
-            assert_eq!(m.remodule::<T>(), m_recovered.remodule::<T>());
+            assert_eq!(m.remodule(param.t), m_recovered.remodule(param.t));
         }
 
         Ok(())

M gfhe/src/glwe.rs → gfhe/src/glwe.rs

@@ -8,79 +8,108 @@ use rand_distr::{Normal, Uniform};
 use std::iter::Sum;
 use std::ops::{Add, AddAssign, Mul, Sub};
 
-use arith::{Ring, Rq, Zq, TR};
+use arith::{Ring, RingParam, Rq, Zq, TR};
 
 use crate::glev::GLev;
 
 // const ERR_SIGMA: f64 = 3.2;
 const ERR_SIGMA: f64 = 0.0; // TODO WIP
 
+#[derive(Clone, Copy, Debug)]
+pub struct Param {
+    pub ring: RingParam,
+    pub k: usize,
+    pub t: u64,
+}
+impl Param {
+    // returns the plaintext params
+    pub fn pt(&self) -> RingParam {
+        RingParam {
+            q: self.t,
+            n: self.ring.n,
+        }
+    }
+}
+
 /// GLWE implemented over the `Ring` trait, so that it can be also instantiated
 /// over the Torus polynomials 𝕋_<N,q>[X] = 𝕋_q[X]/ (X^N+1).
 #[derive(Clone, Debug)]
-pub struct GLWE<R: Ring, const K: usize>(pub TR<R, K>, pub R);
+pub struct GLWE<R: Ring>(pub TR<R>, pub R);
 
 #[derive(Clone, Debug)]
-pub struct SecretKey<R: Ring, const K: usize>(pub TR<R, K>);
+pub struct SecretKey<R: Ring>(pub TR<R>);
 #[derive(Clone, Debug)]
-pub struct PublicKey<R: Ring, const K: usize>(pub R, pub TR<R, K>);
+pub struct PublicKey<R: Ring>(pub R, pub TR<R>);
 
 // K GLevs, each KSK_i=l GLWEs
 #[derive(Clone, Debug)]
-pub struct KSK<R: Ring, const K: usize>(Vec<GLev<R, K>>);
+pub struct KSK<R: Ring>(Vec<GLev<R>>);
 
-impl<R: Ring, const K: usize> GLWE<R, K> {
-    pub fn zero() -> Self {
-        Self(TR::zero(), R::zero())
+impl<R: Ring> GLWE<R> {
+    pub fn zero(k: usize, params: &RingParam) -> Self {
+        Self(TR::zero(k, &params), R::zero(&params))
     }
-    pub fn from_plaintext(p: R) -> Self {
-        Self(TR::zero(), p)
+    pub fn from_plaintext(k: usize, param: &RingParam, p: R) -> Self {
+        Self(TR::zero(k, &param), p)
     }
 
-    pub fn new_key(mut rng: impl Rng) -> Result<(SecretKey<R, K>, PublicKey<R, K>)> {
+    pub fn new_key(mut rng: impl Rng, param: &Param) -> Result<(SecretKey<R>, PublicKey<R>)> {
         let Xi_key = Uniform::new(0_f64, 2_f64);
         let Xi_err = Normal::new(0_f64, ERR_SIGMA)?;
 
-        let s: TR<R, K> = TR::rand(&mut rng, Xi_key);
-        let a: TR<R, K> = TR::rand(&mut rng, Uniform::new(0_f64, R::Q as f64));
-        let e = R::rand(&mut rng, Xi_err);
+        let s: TR<R> = TR::rand(&mut rng, Xi_key, param.k, &param.ring);
+        let a: TR<R> = TR::rand(
+            &mut rng,
+            Uniform::new(0_f64, param.ring.q as f64),
+            param.k,
+            &param.ring,
+        );
+        let e = R::rand(&mut rng, Xi_err, &param.ring);
 
-        let pk: PublicKey<R, K> = PublicKey((&a * &s) + e, a);
+        let pk: PublicKey<R> = PublicKey((&a * &s) + e, a);
         Ok((SecretKey(s), pk))
     }
-    pub fn pk_from_sk(mut rng: impl Rng, sk: SecretKey<R, K>) -> Result<PublicKey<R, K>> {
+    pub fn pk_from_sk(mut rng: impl Rng, param: &Param, sk: SecretKey<R>) -> Result<PublicKey<R>> {
         let Xi_err = Normal::new(0_f64, ERR_SIGMA)?;
 
-        let a: TR<R, K> = TR::rand(&mut rng, Uniform::new(0_f64, R::Q as f64));
-        let e = R::rand(&mut rng, Xi_err);
+        let a: TR<R> = TR::rand(
+            &mut rng,
+            Uniform::new(0_f64, param.ring.q as f64),
+            param.k,
+            &param.ring,
+        );
+        let e = R::rand(&mut rng, Xi_err, &param.ring);
 
-        let pk: PublicKey<R, K> = PublicKey((&a * &sk.0) + e, a);
+        let pk: PublicKey<R> = PublicKey((&a * &sk.0) + e, a);
         Ok(pk)
     }
 
     pub fn new_ksk(
         mut rng: impl Rng,
+        param: &Param,
         beta: u32,
         l: u32,
-        sk: &SecretKey<R, K>,
-        new_sk: &SecretKey<R, K>,
-    ) -> Result<KSK<R, K>> {
-        let r: Vec<GLev<R, K>> = (0..K)
+        sk: &SecretKey<R>,
+        new_sk: &SecretKey<R>,
+    ) -> Result<KSK<R>> {
+        debug_assert_eq!(param.k, sk.0.k);
+        let k = sk.0.k;
+        let r: Vec<GLev<R>> = (0..k)
             .into_iter()
             .map(|i|
                 // treat sk_i as the msg being encrypted
-                GLev::<R, K>::encrypt_s(&mut rng, beta, l, &new_sk, &sk.0 .0[i]))
+                GLev::<R>::encrypt_s(&mut rng, param, beta, l, &new_sk, &sk.0 .r[i]))
             .collect::<Result<Vec<_>>>()?;
 
         Ok(KSK(r))
     }
-    pub fn key_switch(&self, beta: u32, l: u32, ksk: &KSK<R, K>) -> Self {
-        let (a, b): (TR<R, K>, R) = (self.0.clone(), self.1);
+    pub fn key_switch(&self, param: &Param, beta: u32, l: u32, ksk: &KSK<R>) -> Self {
+        let (a, b): (TR<R>, R) = (self.0.clone(), self.1.clone()); // TODO rm clones
 
-        let lhs: GLWE<R, K> = GLWE(TR::zero(), b);
+        let lhs: GLWE<R> = GLWE(TR::zero(param.k, &param.ring), b);
 
         // K iterations, ksk.0 contains K times GLev
-        let rhs: GLWE<R, K> = zip_eq(a.0, ksk.0.clone())
+        let rhs: GLWE<R> = zip_eq(a.r, ksk.0.clone())
             .map(|(a_i, ksk_i)| ksk_i * a_i.decompose(beta, l)) // dot_product
             .sum();
 
@@ -90,121 +119,136 @@
     // encrypts with the given SecretKey (instead of PublicKey)
     pub fn encrypt_s(
         mut rng: impl Rng,
-        sk: &SecretKey<R, K>,
+        param: &Param,
+        sk: &SecretKey<R>,
         m: &R, // already scaled
     ) -> Result<Self> {
         let Xi_key = Uniform::new(0_f64, 2_f64);
         let Xi_err = Normal::new(0_f64, ERR_SIGMA)?;
 
-        let a: TR<R, K> = TR::rand(&mut rng, Xi_key);
-        let e = R::rand(&mut rng, Xi_err);
+        let a: TR<R> = TR::rand(&mut rng, Xi_key, param.k, &param.ring);
+        let e = R::rand(&mut rng, Xi_err, &param.ring);
 
-        let b: R = (&a * &sk.0) + *m + e;
+        let b: R = (&a * &sk.0) + m.clone() + e; // TODO rm clone
         Ok(Self(a, b))
     }
     pub fn encrypt(
         mut rng: impl Rng,
-        pk: &PublicKey<R, K>,
+        param: &Param,
+        pk: &PublicKey<R>,
         m: &R, // already scaled
     ) -> Result<Self> {
         let Xi_key = Uniform::new(0_f64, 2_f64);
         let Xi_err = Normal::new(0_f64, ERR_SIGMA)?;
 
-        let u: R = R::rand(&mut rng, Xi_key);
+        let u: R = R::rand(&mut rng, Xi_key, &param.ring);
 
-        let e0 = R::rand(&mut rng, Xi_err);
-        let e1 = TR::<R, K>::rand(&mut rng, Xi_err);
+        let e0 = R::rand(&mut rng, Xi_err, &param.ring);
+        let e1 = TR::<R>::rand(&mut rng, Xi_err, param.k, &param.ring);
 
-        let b: R = pk.0.clone() * u.clone() + *m + e0;
-        let d: TR<R, K> = &pk.1 * &u + e1;
+        let b: R = pk.0.clone() * u.clone() + m.clone() + e0; // TODO rm clones
+        let d: TR<R> = &pk.1 * &u + e1;
 
         Ok(Self(d, b))
     }
     // returns m' not downscaled
-    pub fn decrypt(&self, sk: &SecretKey<R, K>) -> R {
-        let (d, b): (TR<R, K>, R) = (self.0.clone(), self.1);
+    pub fn decrypt(&self, sk: &SecretKey<R>) -> R {
+        let (d, b): (TR<R>, R) = (self.0.clone(), self.1.clone());
         let p: R = b - &d * &sk.0;
         p
     }
 }
 
 // Methods for when Ring=Rq<Q,N>
-impl<const Q: u64, const N: usize, const K: usize> GLWE<Rq<Q, N>, K> {
+impl GLWE<Rq> {
     // scale up
-    pub fn encode<const T: u64>(m: &Rq<T, N>) -> Rq<Q, N> {
-        let m = m.remodule::<Q>();
-        let delta = Q / T; // floored
+    pub fn encode(param: &Param, m: &Rq) -> Rq {
+        debug_assert_eq!(param.t, m.param.q);
+        let m = m.remodule(param.ring.q);
+        let delta = param.ring.q / param.t; // floored
         m * delta
     }
     // scale down
-    pub fn decode<const T: u64>(m: &Rq<Q, N>) -> Rq<T, N> {
-        let r = m.mul_div_round(T, Q);
-        let r: Rq<T, N> = r.remodule::<T>();
+    pub fn decode(param: &Param, m: &Rq) -> Rq {
+        let r = m.mul_div_round(param.t, param.ring.q);
+        let r: Rq = r.remodule(param.t);
         r
     }
-    pub fn mod_switch<const P: u64>(&self) -> GLWE<Rq<P, N>, K> {
-        let a: TR<Rq<P, N>, K> = TR(self
-            .0
-             .0
-            .iter()
-            .map(|r| r.mod_switch::<P>())
-            .collect::<Vec<_>>());
-        let b: Rq<P, N> = self.1.mod_switch::<P>();
+    pub fn mod_switch(&self, p: u64) -> GLWE<Rq> {
+        let a: TR<Rq> = TR {
+            k: self.0.k,
+            r: self.0.r.iter().map(|r| r.mod_switch(p)).collect::<Vec<_>>(),
+        };
+        let b: Rq = self.1.mod_switch(p);
         GLWE(a, b)
     }
 }
 
-impl<R: Ring, const K: usize> Add<GLWE<R, K>> for GLWE<R, K> {
+impl<R: Ring> Add<GLWE<R>> for GLWE<R> {
     type Output = Self;
     fn add(self, other: Self) -> Self {
-        let a: TR<R, K> = self.0 + other.0;
+        let a: TR<R> = self.0 + other.0;
         let b: R = self.1 + other.1;
         Self(a, b)
     }
 }
 
-impl<R: Ring, const K: usize> Add<R> for GLWE<R, K> {
+impl<R: Ring> Add<R> for GLWE<R> {
     type Output = Self;
     fn add(self, plaintext: R) -> Self {
-        let a: TR<R, K> = self.0;
+        let a: TR<R> = self.0;
         let b: R = self.1 + plaintext;
         Self(a, b)
     }
 }
-impl<R: Ring, const K: usize> AddAssign for GLWE<R, K> {
+impl<R: Ring> AddAssign for GLWE<R> {
     fn add_assign(&mut self, rhs: Self) {
-        for i in 0..K {
-            self.0 .0[i] = self.0 .0[i].clone() + rhs.0 .0[i].clone();
+        debug_assert_eq!(self.0.k, rhs.0.k);
+        debug_assert_eq!(self.1.param(), rhs.1.param());
+
+        let k = self.0.k;
+        for i in 0..k {
+            self.0.r[i] = self.0.r[i].clone() + rhs.0.r[i].clone();
         }
         self.1 = self.1.clone() + rhs.1.clone();
     }
 }
-impl<R: Ring, const K: usize> Sum<GLWE<R, K>> for GLWE<R, K> {
-    fn sum<I>(iter: I) -> Self
+impl<R: Ring> Sum<GLWE<R>> for GLWE<R> {
+    fn sum<I>(mut iter: I) -> Self
     where
         I: Iterator<Item = Self>,
     {
-        let mut acc = GLWE::<R, K>::zero();
-        for e in iter {
-            acc += e;
-        }
-        acc
+        // let mut acc = GLWE::<R>::zero();
+        // for e in iter {
+        //     acc += e;
+        // }
+        // acc
+        let first = iter.next().unwrap();
+        iter.fold(first, |acc, e| acc + e)
     }
 }
 
-impl<R: Ring, const K: usize> Sub<GLWE<R, K>> for GLWE<R, K> {
+impl<R: Ring> Sub<GLWE<R>> for GLWE<R> {
     type Output = Self;
     fn sub(self, other: Self) -> Self {
-        let a: TR<R, K> = self.0 - other.0;
+        let a: TR<R> = self.0 - other.0;
         let b: R = self.1 - other.1;
         Self(a, b)
     }
 }
 
-impl<R: Ring, const K: usize> Mul<R> for GLWE<R, K> {
+impl<R: Ring> Mul<R> for GLWE<R> {
     type Output = Self;
     fn mul(self, plaintext: R) -> Self {
-        let a: TR<R, K> = TR(self.0 .0.iter().map(|r_i| *r_i * plaintext).collect());
+        let a: TR<R> = TR {
+            k: self.0.k,
+            r: self
+                .0
+                .r
+                .iter()
+                .map(|r_i| r_i.clone() * plaintext.clone())
+                .collect(),
+        };
         let b: R = self.1 * plaintext;
         Self(a, b)
     }
@@ -255,77 +299,93 @@
     use super::*;
 
     #[test]
-    fn test_encrypt_decrypt() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 128;
-        const T: u64 = 32; // plaintext modulus
-        const K: usize = 16;
-        type S = GLWE<Rq<Q, N>, K>;
+    fn test_encrypt_decrypt_ring_nq() -> Result<()> {
+        let param = Param {
+            ring: RingParam {
+                q: 2u64.pow(16) + 1,
+                n: 128,
+            },
+            k: 16,
+            t: 32, // plaintext modulus
+        };
+        // let k: usize = 16;
+        type S = GLWE<Rq>;
 
         let mut rng = rand::thread_rng();
-        let msg_dist = Uniform::new(0_u64, T);
+        let msg_dist = Uniform::new(0_u64, param.t);
 
         for _ in 0..200 {
-            let (sk, pk) = S::new_key(&mut rng)?;
+            let (sk, pk) = S::new_key(&mut rng, &param)?;
 
-            let m = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?; // msg
-                                                               // let m: Rq<Q, N> = m.remodule::<Q>();
+            let m = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?; // msg
+                                                                    // let m: Rq<Q, N> = m.remodule::<Q>();
 
-            let p = S::encode::<T>(&m); // plaintext
-            let c = S::encrypt(&mut rng, &pk, &p)?; // ciphertext
+            let p = S::encode(&param, &m); // plaintext
+            let c = S::encrypt(&mut rng, &param, &pk, &p)?; // ciphertext
             let p_recovered = c.decrypt(&sk);
-            let m_recovered = S::decode::<T>(&p_recovered);
+            let m_recovered = S::decode(&param, &p_recovered);
 
-            assert_eq!(m.remodule::<T>(), m_recovered.remodule::<T>());
+            assert_eq!(m.remodule(param.t), m_recovered.remodule(param.t));
 
             // same but using encrypt_s (with sk instead of pk))
-            let c = S::encrypt_s(&mut rng, &sk, &p)?;
+            let c = S::encrypt_s(&mut rng, &param, &sk, &p)?;
             let p_recovered = c.decrypt(&sk);
-            let m_recovered = S::decode::<T>(&p_recovered);
+            let m_recovered = S::decode(&param, &p_recovered);
 
-            assert_eq!(m.remodule::<T>(), m_recovered.remodule::<T>());
+            assert_eq!(m.remodule(param.t), m_recovered.remodule(param.t));
         }
 
         Ok(())
     }
 
     use arith::{Tn, T64};
-    use std::array;
-    pub fn t_encode<const P: u64>(m: &Rq<P, 4>) -> Tn<4> {
-        let delta = u64::MAX / P; // floored
+    pub fn t_encode(param: &RingParam, m: &Rq) -> Tn {
+        let p = m.param.q; // plaintext space
+        let delta = u64::MAX / p; // floored
         let coeffs = m.coeffs();
-        Tn(array::from_fn(|i| T64(coeffs[i].0 * delta)))
+        // Tn(array::from_fn(|i| T64(coeffs[i].0 * delta)))
+        // Tn{param, coeffs: array::from_fn(|i| T64(coeffs[i].0 * delta)))
+        Tn {
+            param: *param,
+            coeffs: coeffs.iter().map(|c_i| T64(c_i.v * delta)).collect(),
+        }
     }
-    pub fn t_decode<const P: u64>(p: &Tn<4>) -> Rq<P, 4> {
-        let p = p.mul_div_round(P, u64::MAX);
-        Rq::<P, 4>::from_vec_u64(p.coeffs().iter().map(|c| c.0).collect())
+    pub fn t_decode(param: &Param, pt: &Tn) -> Rq {
+        let p = param.t;
+        let pt = pt.mul_div_round(p, u64::MAX);
+        Rq::from_vec_u64(&param.pt(), pt.coeffs().iter().map(|c| c.0).collect())
     }
     #[test]
     fn test_encrypt_decrypt_torus() -> Result<()> {
-        const N: usize = 128;
-        const T: u64 = 32; // plaintext modulus
-        const K: usize = 16;
-        type S = GLWE<Tn<4>, K>;
+        let param = Param {
+            ring: RingParam {
+                q: u64::MAX,
+                n: 128,
+            },
+            k: 16,
+            t: 32, // plaintext modulus
+        };
+        type S = GLWE<Tn>;
 
         let mut rng = rand::thread_rng();
-        let msg_dist = Uniform::new(0_f64, T as f64);
+        let msg_dist = Uniform::new(0_f64, param.t as f64);
 
         for _ in 0..200 {
-            let (sk, pk) = S::new_key(&mut rng)?;
+            let (sk, pk) = S::new_key(&mut rng, &param)?;
 
-            let m = Rq::<T, 4>::rand(&mut rng, msg_dist); // msg
+            let m = Rq::rand(&mut rng, msg_dist, &param.pt()); // msg
 
-            let p = t_encode::<T>(&m); // plaintext
-            let c = S::encrypt(&mut rng, &pk, &p)?; // ciphertext
+            let p = t_encode(&param.ring, &m); // plaintext
+            let c = S::encrypt(&mut rng, &param, &pk, &p)?; // ciphertext
             let p_recovered = c.decrypt(&sk);
-            let m_recovered = t_decode::<T>(&p_recovered);
+            let m_recovered = t_decode(&param, &p_recovered);
 
             assert_eq!(m, m_recovered);
 
             // same but using encrypt_s (with sk instead of pk))
-            let c = S::encrypt_s(&mut rng, &sk, &p)?;
+            let c = S::encrypt_s(&mut rng, &param, &sk, &p)?;
             let p_recovered = c.decrypt(&sk);
-            let m_recovered = t_decode::<T>(&p_recovered);
+            let m_recovered = t_decode(&param, &p_recovered);
 
             assert_eq!(m, m_recovered);
         }
@@ -335,32 +395,36 @@ }
 
     #[test]
     fn test_addition() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 128;
-        const T: u64 = 20;
-        const K: usize = 16;
-        type S = GLWE<Rq<Q, N>, K>;
+        let param = Param {
+            ring: RingParam {
+                q: 2u64.pow(16) + 1,
+                n: 128,
+            },
+            k: 16,
+            t: 20, // plaintext modulus
+        };
+        type S = GLWE<Rq>;
 
         let mut rng = rand::thread_rng();
-        let msg_dist = Uniform::new(0_u64, T);
+        let msg_dist = Uniform::new(0_u64, param.t);
 
         for _ in 0..200 {
-            let (sk, pk) = S::new_key(&mut rng)?;
+            let (sk, pk) = S::new_key(&mut rng, &param)?;
 
-            let m1 = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
-            let m2 = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
-            let p1: Rq<Q, N> = S::encode::<T>(&m1); // plaintext
-            let p2: Rq<Q, N> = S::encode::<T>(&m2); // plaintext
+            let m1 = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
+            let m2 = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
+            let p1: Rq = S::encode(&param, &m1); // plaintext
+            let p2: Rq = S::encode(&param, &m2); // plaintext
 
-            let c1 = S::encrypt(&mut rng, &pk, &p1)?;
-            let c2 = S::encrypt(&mut rng, &pk, &p2)?;
+            let c1 = S::encrypt(&mut rng, &param, &pk, &p1)?;
+            let c2 = S::encrypt(&mut rng, &param, &pk, &p2)?;
 
             let c3 = c1 + c2;
 
             let p3_recovered = c3.decrypt(&sk);
-            let m3_recovered = S::decode::<T>(&p3_recovered);
+            let m3_recovered = S::decode(&param, &p3_recovered);
 
-            assert_eq!((m1 + m2).remodule::<T>(), m3_recovered.remodule::<T>());
+            assert_eq!((m1 + m2).remodule(param.t), m3_recovered.remodule(param.t));
         }
 
         Ok(())
@@ -368,31 +432,35 @@ }
 
     #[test]
     fn test_add_plaintext() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 128;
-        const T: u64 = 32;
-        const K: usize = 16;
-        type S = GLWE<Rq<Q, N>, K>;
+        let param = Param {
+            ring: RingParam {
+                q: 2u64.pow(16) + 1,
+                n: 128,
+            },
+            k: 16,
+            t: 32, // plaintext modulus
+        };
+        type S = GLWE<Rq>;
 
         let mut rng = rand::thread_rng();
-        let msg_dist = Uniform::new(0_u64, T);
+        let msg_dist = Uniform::new(0_u64, param.t);
 
         for _ in 0..200 {
-            let (sk, pk) = S::new_key(&mut rng)?;
+            let (sk, pk) = S::new_key(&mut rng, &param)?;
 
-            let m1 = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
-            let m2 = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
-            let p1: Rq<Q, N> = S::encode::<T>(&m1); // plaintext
-            let p2: Rq<Q, N> = S::encode::<T>(&m2); // plaintext
+            let m1 = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
+            let m2 = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
+            let p1: Rq = S::encode(&param, &m1); // plaintext
+            let p2: Rq = S::encode(&param, &m2); // plaintext
 
-            let c1 = S::encrypt(&mut rng, &pk, &p1)?;
+            let c1 = S::encrypt(&mut rng, &param, &pk, &p1)?;
 
             let c3 = c1 + p2;
 
             let p3_recovered = c3.decrypt(&sk);
-            let m3_recovered = S::decode::<T>(&p3_recovered);
+            let m3_recovered = S::decode(&param, &p3_recovered);
 
-            assert_eq!((m1 + m2).remodule::<T>(), m3_recovered.remodule::<T>());
+            assert_eq!((m1 + m2).remodule(param.t), m3_recovered.remodule(param.t));
         }
 
         Ok(())
@@ -400,30 +468,34 @@ }
 
     #[test]
     fn test_mul_plaintext() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 16;
-        const T: u64 = 4;
-        const K: usize = 16;
-        type S = GLWE<Rq<Q, N>, K>;
+        let param = Param {
+            ring: RingParam {
+                q: 2u64.pow(16) + 1,
+                n: 16,
+            },
+            k: 16,
+            t: 4, // plaintext modulus
+        };
+        type S = GLWE<Rq>;
 
         let mut rng = rand::thread_rng();
-        let msg_dist = Uniform::new(0_u64, T);
+        let msg_dist = Uniform::new(0_u64, param.t);
 
         for _ in 0..200 {
-            let (sk, pk) = S::new_key(&mut rng)?;
+            let (sk, pk) = S::new_key(&mut rng, &param)?;
 
-            let m1 = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
-            let m2 = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
-            let p1: Rq<Q, N> = S::encode::<T>(&m1); // plaintext
-            let p2 = m2.remodule::<Q>(); // notice we don't encode (scale by delta)
+            let m1 = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
+            let m2 = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
+            let p1: Rq = S::encode(&param, &m1); // plaintext
+            let p2 = m2.remodule(param.ring.q); // notice we don't encode (scale by delta)
 
-            let c1 = S::encrypt(&mut rng, &pk, &p1)?;
+            let c1 = S::encrypt(&mut rng, &param, &pk, &p1)?;
 
             let c3 = c1 * p2;
 
-            let p3_recovered: Rq<Q, N> = c3.decrypt(&sk);
-            let m3_recovered: Rq<T, N> = S::decode::<T>(&p3_recovered);
-            assert_eq!((m1.to_r() * m2.to_r()).to_rq::<T>(), m3_recovered);
+            let p3_recovered: Rq = c3.decrypt(&sk);
+            let m3_recovered: Rq = S::decode(&param, &p3_recovered);
+            assert_eq!((m1.to_r() * m2.to_r()).to_rq(param.t), m3_recovered);
         }
 
         Ok(())
@@ -431,33 +503,48 @@ }
 
     #[test]
     fn test_mod_switch() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const P: u64 = 2u64.pow(8) + 1;
+        let param = Param {
+            ring: RingParam {
+                q: 2u64.pow(16) + 1,
+                n: 8,
+            },
+            k: 16,
+            t: 4, // plaintext modulus, must be a prime or power of a prime
+        };
+        let new_q: u64 = 2u64.pow(8) + 1;
         // note: wip, Q and P chosen so that P/Q is an integer
-        const N: usize = 8;
-        const T: u64 = 4; // plaintext modulus, must be a prime or power of a prime
-        const K: usize = 16;
-        type S = GLWE<Rq<Q, N>, K>;
+        type S = GLWE<Rq>;
 
         let mut rng = rand::thread_rng();
-        let msg_dist = Uniform::new(0_u64, T);
+        let msg_dist = Uniform::new(0_u64, param.t);
 
         for _ in 0..200 {
-            let (sk, pk) = S::new_key(&mut rng)?;
+            let (sk, pk) = S::new_key(&mut rng, &param)?;
 
-            let m = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
+            let m = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
 
-            let p = S::encode::<T>(&m);
-            let c = S::encrypt(&mut rng, &pk, &p)?;
+            let p = S::encode(&param, &m);
+            let c = S::encrypt(&mut rng, &param, &pk, &p)?;
 
-            let c2: GLWE<Rq<P, N>, K> = c.mod_switch::<P>();
-            let sk2: SecretKey<Rq<P, N>, K> =
-                SecretKey(TR(sk.0 .0.iter().map(|s_i| s_i.remodule::<P>()).collect()));
+            let c2: GLWE<Rq> = c.mod_switch(new_q);
+            assert_eq!(c2.1.param.q, new_q);
+            let sk2: SecretKey<Rq> = SecretKey(TR {
+                k: param.k,
+                r: sk.0.r.iter().map(|s_i| s_i.remodule(new_q)).collect(),
+            });
 
             let p_recovered = c2.decrypt(&sk2);
-            let m_recovered = GLWE::<Rq<P, N>, K>::decode::<T>(&p_recovered);
+            let new_param = Param {
+                ring: RingParam {
+                    q: new_q,
+                    n: param.ring.n,
+                },
+                k: param.k,
+                t: param.t,
+            };
+            let m_recovered = GLWE::<Rq>::decode(&new_param, &p_recovered);
 
-            assert_eq!(m.remodule::<T>(), m_recovered.remodule::<T>());
+            assert_eq!(m.remodule(param.t), m_recovered.remodule(param.t));
         }
 
         Ok(())
@@ -465,40 +552,44 @@ }
 
     #[test]
     fn test_key_switch() -> Result<()> {
-        const Q: u64 = 2u64.pow(16) + 1;
-        const N: usize = 128;
-        const T: u64 = 2; // plaintext modulus
-        const K: usize = 16;
-        type S = GLWE<Rq<Q, N>, K>;
+        let param = Param {
+            ring: RingParam {
+                q: 2u64.pow(16) + 1,
+                n: 128,
+            },
+            k: 16,
+            t: 2,
+        };
+        type S = GLWE<Rq>;
 
         let beta: u32 = 2;
         let l: u32 = 16;
 
         let mut rng = rand::thread_rng();
 
-        let (sk, pk) = S::new_key(&mut rng)?;
-        let (sk2, _) = S::new_key(&mut rng)?;
+        let (sk, pk) = S::new_key(&mut rng, &param)?;
+        let (sk2, _) = S::new_key(&mut rng, &param)?;
         // ksk to switch from sk to sk2
-        let ksk = S::new_ksk(&mut rng, beta, l, &sk, &sk2)?;
+        let ksk = S::new_ksk(&mut rng, &param, beta, l, &sk, &sk2)?;
 
-        let msg_dist = Uniform::new(0_u64, T);
-        let m = Rq::<T, N>::rand_u64(&mut rng, msg_dist)?;
-        let p = S::encode::<T>(&m); // plaintext
-                                    //
-        let c = S::encrypt_s(&mut rng, &sk, &p)?;
+        let msg_dist = Uniform::new(0_u64, param.t);
+        let m = Rq::rand_u64(&mut rng, msg_dist, &param.pt())?;
+        let p = S::encode(&param, &m); // plaintext
+                                       //
+        let c = S::encrypt_s(&mut rng, &param, &sk, &p)?;
 
-        let c2 = c.key_switch(beta, l, &ksk);
+        let c2 = c.key_switch(&param, beta, l, &ksk);
 
         // decrypt with the 2nd secret key
         let p_recovered = c2.decrypt(&sk2);
-        let m_recovered = S::decode::<T>(&p_recovered);
-        assert_eq!(m.remodule::<T>(), m_recovered.remodule::<T>());
+        let m_recovered = S::decode(&param, &p_recovered);
+        assert_eq!(m.remodule(param.t), m_recovered.remodule(param.t));
 
         // do the same but now encrypting with pk
-        let c = S::encrypt(&mut rng, &pk, &p)?;
-        let c2 = c.key_switch(beta, l, &ksk);
+        let c = S::encrypt(&mut rng, &param, &pk, &p)?;
+        let c2 = c.key_switch(&param, beta, l, &ksk);
         let p_recovered = c2.decrypt(&sk2);
-        let m_recovered = S::decode::<T>(&p_recovered);
+        let m_recovered = S::decode(&param, &p_recovered);
         assert_eq!(m, m_recovered);
 
         Ok(())