Smash Ciphersuite definitions into their own crates

Uses dalek-ff-group for Ed25519 and Ristretto. Uses minimal-ed448 for Ed448. Adds ciphersuite-kp256 for Secp256k1 and P-256.
2025-12-08 04:09:23 +00:00 · 2025-08-20 04:50:37 -04:00
parent 8be03a8fc2
commit b63ef32864
95 changed files with 322 additions and 184 deletions
--- a/crypto/ciphersuite/Cargo.toml
+++ b/crypto/ciphersuite/Cargo.toml
@@ -26,20 +26,10 @@ subtle = { version = "^2.4", default-features = false }

 digest = { version = "0.10", default-features = false, features = ["core-api"] }
 transcript = { package = "flexible-transcript", path = "../transcript", version = "^0.3.2", default-features = false }
-sha2 = { version = "0.10", default-features = false, optional = true }
-sha3 = { version = "0.10", default-features = false, optional = true }

 ff = { version = "0.13", default-features = false, features = ["bits"] }
 group = { version = "0.13", default-features = false }

-dalek-ff-group = { path = "../dalek-ff-group", version = "0.4", default-features = false, optional = true }
-
-elliptic-curve = { version = "0.13", default-features = false, features = ["hash2curve"], optional = true }
-p256 = { version = "^0.13.1", default-features = false, features = ["arithmetic", "bits", "hash2curve"], optional = true }
-k256 = { version = "^0.13.1", default-features = false, features = ["arithmetic", "bits", "hash2curve"], optional = true }
-
-minimal-ed448 = { path = "../ed448", version = "0.4", default-features = false, optional = true }
-
 [dev-dependencies]
 hex = { version = "0.4", default-features = false, features = ["std"] }

@@ -59,27 +49,8 @@ std = [

  "digest/std",
  "transcript/std",
-  "sha2?/std",
-  "sha3?/std",

  "ff/std",
-
-  "dalek-ff-group?/std",
-
-  "elliptic-curve?/std",
-  "p256?/std",
-  "k256?/std",
-  "minimal-ed448?/std",
 ]

-dalek = ["sha2", "dalek-ff-group"]
-ed25519 = ["dalek"]
-ristretto = ["dalek"]
-
-kp256 = ["sha2", "elliptic-curve"]
-p256 = ["kp256", "dep:p256"]
-secp256k1 = ["kp256", "k256"]
-
-ed448 = ["sha3", "minimal-ed448"]
-
 default = ["std"]
--- a/crypto/ciphersuite/README.md
+++ b/crypto/ciphersuite/README.md
@@ -21,6 +21,8 @@ Their `hash_to_F` is the
 [IETF's hash to curve](https://www.ietf.org/archive/id/draft-irtf-cfrg-hash-to-curve-16.html),
 yet applied to their scalar field.

+Please see the [`ciphersuite-kp256`](https://docs.rs/ciphersuite-kp256) crate for more info.
+
 ### Ed25519/Ristretto

 Ed25519/Ristretto are offered via
@@ -33,6 +35,8 @@ the draft
 [RFC-RISTRETTO](https://www.ietf.org/archive/id/draft-irtf-cfrg-ristretto255-decaf448-05.html).
 The domain-separation tag is naively prefixed to the message.

+Please see the [`dalek-ff-group`](https://docs.rs/dalek-ff-group) crate for more info.
+
 ### Ed448

 Ed448 is offered via [minimal-ed448](https://crates.io/crates/minimal-ed448), an
@@ -42,3 +46,5 @@ to its prime-order subgroup.
 Its `hash_to_F` is the wide reduction of SHAKE256, with a 114-byte output, as
 used in [RFC-8032](https://www.rfc-editor.org/rfc/rfc8032). The
 domain-separation tag is naively prefixed to the message.
+
+Please see the [`minimal-ed448`](https://docs.rs/minimal-ed448) crate for more info.
--- a/crypto/ciphersuite/kp256/Cargo.toml
+++ b/crypto/ciphersuite/kp256/Cargo.toml
@@ -0,0 +1,55 @@
+[package]
+name = "ciphersuite-kp256"
+version = "0.4.0"
+description = "Ciphersuites built around ff/group"
+license = "MIT"
+repository = "https://github.com/serai-dex/serai/tree/develop/crypto/ciphersuite/kp256"
+authors = ["Luke Parker <lukeparker5132@gmail.com>"]
+keywords = ["ciphersuite", "ff", "group"]
+edition = "2021"
+rust-version = "1.66"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[lints]
+workspace = true
+
+[dependencies]
+rand_core = { version = "0.6", default-features = false }
+
+zeroize = { version = "^1.5", default-features = false, features = ["derive"] }
+
+sha2 = { version = "0.10", default-features = false }
+
+elliptic-curve = { version = "0.13", default-features = false, features = ["hash2curve"] }
+p256 = { version = "^0.13.1", default-features = false, features = ["arithmetic", "bits", "hash2curve"] }
+k256 = { version = "^0.13.1", default-features = false, features = ["arithmetic", "bits", "hash2curve"] }
+
+ciphersuite = { path = "../", version = "0.4", default-features = false }
+
+[dev-dependencies]
+hex = { version = "0.4", default-features = false, features = ["std"] }
+
+rand_core = { version = "0.6", default-features = false, features = ["std"] }
+
+ff-group-tests = { version = "0.13", path = "../../ff-group-tests" }
+
+[features]
+alloc = ["ciphersuite/alloc"]
+std = [
+  "rand_core/std",
+
+  "zeroize/std",
+
+  "sha2/std",
+
+  "elliptic-curve/std",
+  "p256/std",
+  "k256/std",
+
+  "ciphersuite/std",
+]
+
+default = ["std"]
--- a/crypto/ciphersuite/kp256/LICENSE
+++ b/crypto/ciphersuite/kp256/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021-2023 Luke Parker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
--- a/crypto/ciphersuite/kp256/README.md
+++ b/crypto/ciphersuite/kp256/README.md
@@ -0,0 +1,3 @@
+# Ciphersuite {k, p}256
+
+SECP256k1 and P-256 Ciphersuites around k256 and p256.
--- a/crypto/ciphersuite/kp256/src/lib.rs
+++ b/crypto/ciphersuite/kp256/src/lib.rs
@@ -1,16 +1,17 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
 use zeroize::Zeroize;

 use sha2::Sha256;

-use group::ff::PrimeField;
-
 use elliptic_curve::{
  generic_array::GenericArray,
  bigint::{NonZero, CheckedAdd, Encoding, U384},
  hash2curve::{Expander, ExpandMsg, ExpandMsgXmd},
 };

-use crate::Ciphersuite;
+use ciphersuite::{group::ff::PrimeField, Ciphersuite};

 macro_rules! kp_curve {
  (
@@ -107,12 +108,9 @@ fn test_oversize_dst<C: Ciphersuite>() {
 /// Ciphersuite for Secp256k1.
 ///
 /// hash_to_F is implemented via the IETF draft for hash to curve's hash_to_field (v16).
-#[cfg(feature = "secp256k1")]
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize)]
 pub struct Secp256k1;
-#[cfg(feature = "secp256k1")]
 kp_curve!("secp256k1", k256, Secp256k1, b"secp256k1");
-#[cfg(feature = "secp256k1")]
 #[test]
 fn test_secp256k1() {
  ff_group_tests::group::test_prime_group_bits::<_, k256::ProjectivePoint>(&mut rand_core::OsRng);
@@ -145,12 +143,9 @@ fn test_secp256k1() {
 /// Ciphersuite for P-256.
 ///
 /// hash_to_F is implemented via the IETF draft for hash to curve's hash_to_field (v16).
-#[cfg(feature = "p256")]
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize)]
 pub struct P256;
-#[cfg(feature = "p256")]
 kp_curve!("p256", p256, P256, b"P-256");
-#[cfg(feature = "p256")]
 #[test]
 fn test_p256() {
  ff_group_tests::group::test_prime_group_bits::<_, p256::ProjectivePoint>(&mut rand_core::OsRng);
--- a/crypto/ciphersuite/src/lib.md
+++ b/crypto/ciphersuite/src/lib.md
@@ -2,7 +2,7 @@

 Ciphersuites for elliptic curves premised on ff/group.

-This library, except for the not recommended Ed448 ciphersuite, was
+This library was
 [audited by Cypher Stack in March 2023](https://github.com/serai-dex/serai/raw/e1bb2c191b7123fd260d008e31656d090d559d21/audits/Cypher%20Stack%20crypto%20March%202023/Audit.pdf),
 culminating in commit
 [669d2dbffc1dafb82a09d9419ea182667115df06](https://github.com/serai-dex/serai/tree/669d2dbffc1dafb82a09d9419ea182667115df06).
--- a/crypto/ciphersuite/src/lib.rs
+++ b/crypto/ciphersuite/src/lib.rs
@@ -26,25 +26,6 @@ use group::{
 #[cfg(any(feature = "alloc", feature = "std"))]
 use group::GroupEncoding;

-#[cfg(feature = "dalek")]
-mod dalek;
-#[cfg(feature = "ristretto")]
-pub use dalek::Ristretto;
-#[cfg(feature = "ed25519")]
-pub use dalek::Ed25519;
-
-#[cfg(feature = "kp256")]
-mod kp256;
-#[cfg(feature = "secp256k1")]
-pub use kp256::Secp256k1;
-#[cfg(feature = "p256")]
-pub use kp256::P256;
-
-#[cfg(feature = "ed448")]
-mod ed448;
-#[cfg(feature = "ed448")]
-pub use ed448::*;
-
 /// Unified trait defining a ciphersuite around an elliptic curve.
 pub trait Ciphersuite:
  'static + Send + Sync + Clone + Copy + PartialEq + Eq + Debug + Zeroize
--- a/crypto/dalek-ff-group/Cargo.toml
+++ b/crypto/dalek-ff-group/Cargo.toml
@@ -25,18 +25,22 @@ subtle = { version = "^2.4", default-features = false }
 rand_core = { version = "0.6", default-features = false }

 digest = { version = "0.10", default-features = false }
+sha2 = { version = "0.10", default-features = false }

 ff = { version = "0.13", default-features = false, features = ["bits"] }
 group = { version = "0.13", default-features = false }
+ciphersuite = { path = "../ciphersuite", default-features = false }

 crypto-bigint = { version = "0.5", default-features = false, features = ["zeroize"] }

 curve25519-dalek = { version = ">= 4.0, < 4.2", default-features = false, features = ["alloc", "zeroize", "digest", "group", "precomputed-tables"] }

 [dev-dependencies]
+hex = "0.4"
 rand_core = { version = "0.6", default-features = false, features = ["std"] }
 ff-group-tests = { path = "../ff-group-tests" }

 [features]
-std = ["zeroize/std", "subtle/std", "rand_core/std", "digest/std"]
+alloc = ["zeroize/alloc", "ciphersuite/alloc"]
+std = ["alloc", "zeroize/std", "subtle/std", "rand_core/std", "digest/std", "sha2/std", "ciphersuite/std"]
 default = ["std"]
--- a/crypto/dalek-ff-group/src/ciphersuite.rs
+++ b/crypto/dalek-ff-group/src/ciphersuite.rs
@@ -3,9 +3,9 @@ use zeroize::Zeroize;
 use sha2::{Digest, Sha512};

 use group::Group;
-use dalek_ff_group::Scalar;
+use crate::Scalar;

-use crate::Ciphersuite;
+use ciphersuite::Ciphersuite;

 macro_rules! dalek_curve {
  (
@@ -15,7 +15,7 @@ macro_rules! dalek_curve {
    $Point:       ident,
    $ID:          literal
  ) => {
-    use dalek_ff_group::$Point;
+    use crate::$Point;

    impl Ciphersuite for $Ciphersuite {
      type F = Scalar;
@@ -40,12 +40,9 @@ macro_rules! dalek_curve {
 /// hash_to_F is implemented with a naive concatenation of the dst and data, allowing transposition
 /// between the two. This means `dst: b"abc", data: b"def"`, will produce the same scalar as
 /// `dst: "abcdef", data: b""`. Please use carefully, not letting dsts be substrings of each other.
-#[cfg(any(test, feature = "ristretto"))]
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize)]
 pub struct Ristretto;
-#[cfg(any(test, feature = "ristretto"))]
 dalek_curve!("ristretto", Ristretto, RistrettoPoint, b"ristretto");
-#[cfg(any(test, feature = "ristretto"))]
 #[test]
 fn test_ristretto() {
  ff_group_tests::group::test_prime_group_bits::<_, RistrettoPoint>(&mut rand_core::OsRng);
@@ -71,12 +68,9 @@ fn test_ristretto() {
 /// hash_to_F is implemented with a naive concatenation of the dst and data, allowing transposition
 /// between the two. This means `dst: b"abc", data: b"def"`, will produce the same scalar as
 /// `dst: "abcdef", data: b""`. Please use carefully, not letting dsts be substrings of each other.
-#[cfg(feature = "ed25519")]
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize)]
 pub struct Ed25519;
-#[cfg(feature = "ed25519")]
 dalek_curve!("ed25519", Ed25519, EdwardsPoint, b"edwards25519");
-#[cfg(feature = "ed25519")]
 #[test]
 fn test_ed25519() {
  ff_group_tests::group::test_prime_group_bits::<_, EdwardsPoint>(&mut rand_core::OsRng);
--- a/crypto/dalek-ff-group/src/lib.rs
+++ b/crypto/dalek-ff-group/src/lib.rs
@@ -38,6 +38,9 @@ use group::{
 mod field;
 pub use field::FieldElement;

+mod ciphersuite;
+pub use crate::ciphersuite::{Ed25519, Ristretto};
+
 // Use black_box when possible
 #[rustversion::since(1.66)]
 mod black_box {
--- a/crypto/dkg/Cargo.toml
+++ b/crypto/dkg/Cargo.toml
@@ -27,9 +27,6 @@ borsh = { version = "1", default-features = false, features = ["derive", "de_str

 ciphersuite = { path = "../ciphersuite", version = "^0.4.1", default-features = false, features = ["alloc"] }

-[dev-dependencies]
-ciphersuite = { path = "../ciphersuite", default-features = false, features = ["ristretto"] }
-
 [features]
 std = [
  "thiserror/std",
--- a/crypto/dkg/musig/Cargo.toml
+++ b/crypto/dkg/musig/Cargo.toml
@@ -31,7 +31,7 @@ dkg = { path = "../", version = "0.6", default-features = false }

 [dev-dependencies]
 rand_core = { version = "0.6", default-features = false, features = ["getrandom"] }
-ciphersuite = { path = "../../ciphersuite", default-features = false, features = ["ristretto"] }
+dalek-ff-group = { path = "../../dalek-ff-group" }
 dkg-recovery = { path = "../recovery", default-features = false, features = ["std"] }

 [features]
--- a/crypto/dkg/musig/src/tests.rs
+++ b/crypto/dkg/musig/src/tests.rs
@@ -3,7 +3,8 @@ use std::collections::HashMap;
 use zeroize::Zeroizing;
 use rand_core::OsRng;

-use ciphersuite::{group::ff::Field, Ciphersuite, Ristretto};
+use dalek_ff_group::Ristretto;
+use ciphersuite::{group::ff::Field, Ciphersuite};

 use dkg_recovery::recover_key;
 use crate::*;
--- a/crypto/dkg/pedpop/Cargo.toml
+++ b/crypto/dkg/pedpop/Cargo.toml
@@ -34,4 +34,4 @@ dkg = { path = "../", version = "0.6", default-features = false, features = ["st

 [dev-dependencies]
 rand_core = { version = "0.6", default-features = false, features = ["getrandom"] }
-ciphersuite = { path = "../../ciphersuite", default-features = false, features = ["ristretto"] }
+dalek-ff-group = { path = "../../dalek-ff-group", default-features = false }
--- a/crypto/dkg/pedpop/src/tests.rs
+++ b/crypto/dkg/pedpop/src/tests.rs
@@ -2,7 +2,8 @@ use std::collections::HashMap;

 use rand_core::{RngCore, CryptoRng, OsRng};

-use ciphersuite::{Ciphersuite, Ristretto};
+use dalek_ff_group::Ristretto;
+use ciphersuite::Ciphersuite;

 use crate::*;

--- a/crypto/dkg/promote/Cargo.toml
+++ b/crypto/dkg/promote/Cargo.toml
@@ -30,5 +30,5 @@ dkg = { path = "../", version = "0.6.1", default-features = false, features = ["
 [dev-dependencies]
 zeroize = { version = "^1.5", default-features = false, features = ["std", "zeroize_derive"] }
 rand_core = { version = "0.6", default-features = false, features = ["getrandom"] }
-ciphersuite = { path = "../../ciphersuite", default-features = false, features = ["ristretto"] }
+dalek-ff-group = { path = "../../dalek-ff-group" }
 dkg-recovery = { path = "../recovery", default-features = false, features = ["std"] }
--- a/crypto/dkg/promote/src/tests.rs
+++ b/crypto/dkg/promote/src/tests.rs
@@ -4,9 +4,10 @@ use std::collections::HashMap;
 use zeroize::{Zeroize, Zeroizing};
 use rand_core::OsRng;

+use dalek_ff_group::Ristretto;
 use ciphersuite::{
  group::{ff::Field, Group},
-  Ciphersuite, Ristretto,
+  Ciphersuite,
 };

 use dkg::*;
--- a/crypto/ed448/Cargo.toml
+++ b/crypto/ed448/Cargo.toml
@@ -24,8 +24,11 @@ rand_core = { version = "0.6", default-features = false }
 zeroize = { version = "^1.5", default-features = false, features = ["zeroize_derive"] }
 subtle = { version = "^2.4", default-features = false }

+sha3 = { version = "0.10", default-features = false }
+
 ff = { version = "0.13", default-features = false, features = ["bits"] }
 group = { version = "0.13", default-features = false }
+ciphersuite = { path = "../ciphersuite", default-features = false }

 generic-array = { version = "1", default-features = false }
 crypto-bigint = { version = "0.5", default-features = false, features = ["zeroize"] }
@@ -38,5 +41,6 @@ rand_core = { version = "0.6", default-features = false, features = ["std"] }
 ff-group-tests = { path = "../ff-group-tests" }

 [features]
-std = ["rand_core/std", "zeroize/std", "subtle/std", "ff/std"]
+alloc = ["zeroize/alloc", "ciphersuite/alloc"]
+std = ["alloc", "rand_core/std", "zeroize/std", "subtle/std", "sha3/std", "ff/std", "ciphersuite/std"]
 default = ["std"]
--- a/crypto/ed448/src/ciphersuite.rs
+++ b/crypto/ed448/src/ciphersuite.rs
@@ -1,15 +1,17 @@
 use zeroize::Zeroize;

-use digest::{
-  typenum::U114, core_api::BlockSizeUser, Update, Output, OutputSizeUser, FixedOutput,
-  ExtendableOutput, XofReader, HashMarker, Digest,
+use sha3::{
+  digest::{
+    typenum::U114, core_api::BlockSizeUser, Update, Output, OutputSizeUser, FixedOutput,
+    ExtendableOutput, XofReader, HashMarker, Digest,
+  },
+  Shake256,
 };
-use sha3::Shake256;

 use group::Group;
-use minimal_ed448::{Scalar, Point};
+use crate::{Scalar, Point};

-use crate::Ciphersuite;
+use ciphersuite::Ciphersuite;

 /// Shake256, fixed to a 114-byte output, as used by Ed448.
 #[derive(Clone, Default)]
--- a/crypto/ed448/src/lib.rs
+++ b/crypto/ed448/src/lib.rs
@@ -14,3 +14,6 @@ pub use field::FieldElement;

 mod point;
 pub use point::Point;
+
+mod ciphersuite;
+pub use crate::ciphersuite::Ed448;
--- a/crypto/frost/Cargo.toml
+++ b/crypto/frost/Cargo.toml
@@ -34,6 +34,7 @@ dalek-ff-group = { path = "../dalek-ff-group", version = "0.4", default-features
 minimal-ed448 = { path = "../ed448", version = "0.4", default-features = false, features = ["std"], optional = true }

 ciphersuite = { path = "../ciphersuite", version = "^0.4.1", default-features = false, features = ["std"] }
+ciphersuite-kp256 = { path = "../ciphersuite/kp256", version = "0.4", default-features = false, features = ["std"], optional = true }

 multiexp = { path = "../multiexp", version = "0.4", default-features = false, features = ["std", "batch"] }

@@ -52,12 +53,12 @@ dkg-recovery = { path = "../dkg/recovery", default-features = false, features =
 dkg-dealer = { path = "../dkg/dealer", default-features = false, features = ["std"] }

 [features]
-ed25519 = ["dalek-ff-group", "ciphersuite/ed25519"]
-ristretto = ["dalek-ff-group", "ciphersuite/ristretto"]
+ed25519 = ["dalek-ff-group"]
+ristretto = ["dalek-ff-group"]

-secp256k1 = ["ciphersuite/secp256k1"]
-p256 = ["ciphersuite/p256"]
+secp256k1 = ["ciphersuite-kp256"]
+p256 = ["ciphersuite-kp256"]

-ed448 = ["minimal-ed448", "ciphersuite/ed448"]
+ed448 = ["minimal-ed448"]

-tests = ["hex", "rand_core/getrandom", "dkg-dealer" ,"dkg-recovery"]
+tests = ["hex", "rand_core/getrandom", "dkg-dealer", "dkg-recovery"]
--- a/crypto/frost/src/curve/dalek.rs
+++ b/crypto/frost/src/curve/dalek.rs
@@ -16,7 +16,7 @@ macro_rules! dalek_curve {
    $CONTEXT: literal,
    $chal: literal
  ) => {
-    pub use ciphersuite::$Curve;
+    pub use dalek_ff_group::$Curve;

    impl Curve for $Curve {
      const CONTEXT: &'static [u8] = $CONTEXT;
--- a/crypto/frost/src/curve/ed448.rs
+++ b/crypto/frost/src/curve/ed448.rs
@@ -1,7 +1,8 @@
 use digest::Digest;

 use minimal_ed448::{Scalar, Point};
-pub use ciphersuite::{group::GroupEncoding, Shake256_114, Ed448};
+pub use minimal_ed448::Ed448;
+pub use ciphersuite::{group::GroupEncoding, Ciphersuite};

 use crate::{curve::Curve, algorithm::Hram};

@@ -18,7 +19,7 @@ impl Ietf8032Ed448Hram {
  #[allow(non_snake_case)]
  pub(crate) fn hram(context: &[u8], R: &Point, A: &Point, m: &[u8]) -> Scalar {
    Scalar::wide_reduce(
-      Shake256_114::digest(
+      <Ed448 as Ciphersuite>::H::digest(
        [
          &[b"SigEd448".as_ref(), &[0, u8::try_from(context.len()).unwrap()]].concat(),
          context,
--- a/crypto/frost/src/curve/kp256.rs
+++ b/crypto/frost/src/curve/kp256.rs
@@ -11,7 +11,7 @@ macro_rules! kp_curve {

    $CONTEXT: literal
  ) => {
-    pub use ciphersuite::$Curve;
+    pub use ciphersuite_kp256::$Curve;

    impl Curve for $Curve {
      const CONTEXT: &'static [u8] = $CONTEXT;
--- a/crypto/schnorr/Cargo.toml
+++ b/crypto/schnorr/Cargo.toml
@@ -36,7 +36,7 @@ rand_core = { version = "0.6", features = ["std"] }
 sha2 = "0.10"

 dalek-ff-group = { path =  "../dalek-ff-group" }
-ciphersuite = { path = "../ciphersuite", features = ["ed25519"] }
+ciphersuite = { path = "../ciphersuite" }

 [features]
 aggregate = ["transcript"]
--- a/crypto/schnorr/src/tests/mod.rs
+++ b/crypto/schnorr/src/tests/mod.rs
@@ -3,9 +3,10 @@ use core::ops::Deref;
 use zeroize::Zeroizing;
 use rand_core::OsRng;

+use dalek_ff_group::Ed25519;
 use ciphersuite::{
  group::{ff::Field, Group},
-  Ciphersuite, Ed25519,
+  Ciphersuite,
 };
 use multiexp::BatchVerifier;

--- a/crypto/schnorr/src/tests/rfc8032.rs
+++ b/crypto/schnorr/src/tests/rfc8032.rs
@@ -5,8 +5,8 @@

 use sha2::{Digest, Sha512};

-use dalek_ff_group::Scalar;
-use ciphersuite::{group::GroupEncoding, Ciphersuite, Ed25519};
+use dalek_ff_group::{Scalar, Ed25519};
+use ciphersuite::{group::GroupEncoding, Ciphersuite};

 use crate::SchnorrSignature;

--- a/crypto/schnorrkel/Cargo.toml
+++ b/crypto/schnorrkel/Cargo.toml
@@ -24,7 +24,8 @@ transcript = { package = "flexible-transcript", path = "../transcript", version

 group = "0.13"

-ciphersuite = { path = "../ciphersuite", version = "^0.4.1", features = ["std", "ristretto"] }
+dalek-ff-group = { path = "../dalek-ff-group" }
+ciphersuite = { path = "../ciphersuite", version = "^0.4.1", features = ["std"] }
 schnorr = { package = "schnorr-signatures", path = "../schnorr", version = "^0.5.1" }
 frost = { path = "../frost", package = "modular-frost", version = "^0.10.0", features = ["ristretto"] }

--- a/crypto/schnorrkel/src/lib.rs
+++ b/crypto/schnorrkel/src/lib.rs
@@ -9,8 +9,11 @@ use zeroize::Zeroizing;

 use transcript::{Transcript, MerlinTranscript};

-use group::{ff::PrimeField, GroupEncoding};
-use ciphersuite::{Ciphersuite, Ristretto};
+use dalek_ff_group::Ristretto;
+use ciphersuite::{
+  group::{ff::PrimeField, GroupEncoding},
+  Ciphersuite,
+};
 use schnorr::SchnorrSignature;

 use ::frost::{