From bbdb80b07d01043db7d3af0f58b1472cbe5a2864 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 17 Sep 2026 18:20:19 +0530
Subject: [PATCH 1/7] pkc%lint(codeql): track traits alongside method parity in
 `pkc` APIs

---
 maint/codeql/rust/lib/traits.qll | 26 +++++++++++++++++++++++++
 maint/codeql/rust/pkc.ql         | 33 ++++++++++++++++++++++++++++----
 2 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/maint/codeql/rust/lib/traits.qll b/maint/codeql/rust/lib/traits.qll
index b2fd873d..b907def9 100644
--- a/maint/codeql/rust/lib/traits.qll
+++ b/maint/codeql/rust/lib/traits.qll
@@ -102,6 +102,32 @@ predicate implementsTrait(TypeItem t, string traitName) {
   exists(Impl i | i.getSelf() = t and implTraitName(i) = traitName)
 }
 
+/**
+ * Holds if `i`'s trait reference carries a type or const argument, naming
+ * `From<Foo>` rather than `Copy`. A lifetime does not count, since
+ * `Deserialize<'de>` is still a property of the type.
+ */
+private predicate hasTraitTypeArg(Impl i) {
+  exists(GenericArg a |
+    a = implTraitPath(i).getSegment().getGenericArgList().getAGenericArg() and
+    not a instanceof LifetimeArg
+  )
+}
+
+/**
+ * Holds if `t` implements `traitName` and the trait takes no type argument,
+ * through a derive, a hand-written impl, or a macro. Parameterised traits are
+ * excluded.
+ */
+predicate implementsPlainTrait(TypeItem t, string traitName) {
+  exists(Impl i |
+    i.getSelf() = t and
+    fileOf(i).fromSource() and
+    not hasTraitTypeArg(i) and
+    traitName = implTraitName(i)
+  )
+}
+
 /**
  * Holds if `t` has a derived impl for `traitName` under `crate`
  * (i.e. the trait path is `::<crate>::<traitName>`).
diff --git a/maint/codeql/rust/pkc.ql b/maint/codeql/rust/pkc.ql
index 0740f954..57746e4b 100644
--- a/maint/codeql/rust/pkc.ql
+++ b/maint/codeql/rust/pkc.ql
@@ -5,7 +5,7 @@
  *
  * @id base-sdk/pkc-rules
  * @name Rules for dash-pkc
- * @description The arms must offer the same operations under the same names.
+ * @description The arms must offer the same operations and carry the same traits.
  * @kind problem
  * @precision high
  * @problem.severity warning
@@ -77,6 +77,31 @@ predicate shapeGap(TypeItem lacks, string role, string name, string arm) {
   )
 }
 
-from TypeItem t, string role, string name, string arm
-where shapeGap(t, role, name, arm)
-select t, fmt("{0} offers {1}, {2} does not", arm + role, fmt("{0}()", name), t.getName().getText())
+/**
+ * Holds if `lacks` is missing `trait`, which `arm` carries for the same role
+ * inclusive of derives gated by `cfg_attr`.
+ */
+predicate traitGap(TypeItem lacks, string role, string trait, string arm) {
+  exists(TypeItem offers, string lacking |
+    armRole(offers, arm, role) and
+    armRole(lacks, lacking, role) and
+    lacking != arm and
+    implementsPlainTrait(offers, trait) and
+    not implementsPlainTrait(lacks, trait) and
+    not hasDerive(lacks, trait)
+  )
+}
+
+from TypeItem t, string message
+where
+  exists(string role, string name, string arm |
+    shapeGap(t, role, name, arm) and
+    message =
+      fmt("{0} offers {1}, {2} does not", arm + role, fmt("{0}()", name), t.getName().getText())
+  )
+  or
+  exists(string role, string trait, string arm |
+    traitGap(t, role, trait, arm) and
+    message = fmt("{0} implements {1}, {2} does not", arm + role, trait, t.getName().getText())
+  )
+select t, message

From 639a7e064d57954b4779aed44c84e311455af9c7 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 17 Sep 2026 18:20:56 +0530
Subject: [PATCH 2/7] pkc%lint(codeql): introduce suppression list for
 unmatched traits

---
 maint/codeql/rust/lib/pkc.qll   | 10 ++++++----
 maint/codeql/rust/pkc.model.yml |  4 ++++
 maint/codeql/rust/pkc.ql        |  3 ++-
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/maint/codeql/rust/lib/pkc.qll b/maint/codeql/rust/lib/pkc.qll
index 26dd3989..ba96bf1d 100644
--- a/maint/codeql/rust/lib/pkc.qll
+++ b/maint/codeql/rust/lib/pkc.qll
@@ -9,9 +9,11 @@
 /**
  * Holds if `name` belongs to `arm` alone for `role`, exempting the other arms
  * from offering it. Rows live in `pkc.model.yml`.
- *
- * The rows name what an arm lacks rather than what the arms share, so a
- * method added to one arm and forgotten in another is reported with no list
- * to maintain.
  */
 extensible predicate armOnly(string arm, string role, string name);
+
+/**
+ * Holds if `arm` cannot carry `trait` at `role`, though the other arms do.
+ * Rows live in `pkc.model.yml`.
+ */
+extensible predicate armLacksTrait(string arm, string role, string trait);
diff --git a/maint/codeql/rust/pkc.model.yml b/maint/codeql/rust/pkc.model.yml
index 38809e91..4c9342c0 100644
--- a/maint/codeql/rust/pkc.model.yml
+++ b/maint/codeql/rust/pkc.model.yml
@@ -64,3 +64,7 @@ extensions:
       # Recoverable signatures
       - ["Ecdsa", "SecretKey", "sign_recoverable"]        # Sign
       - ["Ecdsa", "PublicKey", "recover"]                 # Get public key from a signature
+  - addsTo:
+      pack: base-sdk/codeql-rust
+      extensible: armLacksTrait
+    data: []
diff --git a/maint/codeql/rust/pkc.ql b/maint/codeql/rust/pkc.ql
index 57746e4b..fb91c227 100644
--- a/maint/codeql/rust/pkc.ql
+++ b/maint/codeql/rust/pkc.ql
@@ -88,7 +88,8 @@ predicate traitGap(TypeItem lacks, string role, string trait, string arm) {
     lacking != arm and
     implementsPlainTrait(offers, trait) and
     not implementsPlainTrait(lacks, trait) and
-    not hasDerive(lacks, trait)
+    not hasDerive(lacks, trait) and
+    not armLacksTrait(lacking, role, trait)
   )
 }
 

From cf4c1283c914879555a7040608fbae37bc314abd Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 17 Sep 2026 17:50:07 +0530
Subject: [PATCH 3/7] pkc%feat(ecdsa): derive `Copy` for
 `Ecdsa{PublicKey,Signature}`

---
 maint/codeql/rust/pkc.model.yml   |  4 +++-
 pkgs/pkc/bench/ecdsa.rs           |  2 +-
 pkgs/pkc/src/ecdsa/public_ops.rs  |  4 ++--
 pkgs/pkc/src/ecdsa/secret_ops.rs  |  4 ++--
 pkgs/pkc/src/ecdsa/sig_ops.rs     |  4 ++--
 pkgs/pkc/src/ecdsa/sig_rec_ops.rs | 10 +++++-----
 6 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/maint/codeql/rust/pkc.model.yml b/maint/codeql/rust/pkc.model.yml
index 4c9342c0..75af2e34 100644
--- a/maint/codeql/rust/pkc.model.yml
+++ b/maint/codeql/rust/pkc.model.yml
@@ -67,4 +67,6 @@ extensions:
   - addsTo:
       pack: base-sdk/codeql-rust
       extensible: armLacksTrait
-    data: []
+    data:
+      - ["Bls", "PublicKey", "Copy"]
+      - ["Bls", "Signature", "Copy"]
diff --git a/pkgs/pkc/bench/ecdsa.rs b/pkgs/pkc/bench/ecdsa.rs
index f9372699..a3a0134c 100644
--- a/pkgs/pkc/bench/ecdsa.rs
+++ b/pkgs/pkc/bench/ecdsa.rs
@@ -30,7 +30,7 @@ fn verify(bencher: divan::Bencher) {
   let pk = sk.public_key();
   bencher
     .counter(divan::counter::ItemsCount::new(1u32))
-    .bench(|| pk.verify(&msg, &sig));
+    .bench(|| pk.verify(&msg, sig));
 }
 
 #[divan::bench]
diff --git a/pkgs/pkc/src/ecdsa/public_ops.rs b/pkgs/pkc/src/ecdsa/public_ops.rs
index b56ff8da..50247a7c 100644
--- a/pkgs/pkc/src/ecdsa/public_ops.rs
+++ b/pkgs/pkc/src/ecdsa/public_ops.rs
@@ -44,7 +44,7 @@ pub(super) enum PkForm {
 }
 
 /// A secp256k1 public key.
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "codec", derive(TypeId))]
 #[cfg_attr(feature = "serde", derive(::serde::Serialize, ::serde::Deserialize))]
 #[cfg_attr(feature = "serde", serde(into = "EcdsaPkBytes", try_from = "EcdsaPkBytes"))]
@@ -413,6 +413,6 @@ mod tests {
   fn verify_rejects_wrong_message(alice_pk: EcdsaPublicKey, alice_sig: EcdsaSignature) {
     let mut bad = MSG;
     bad[0] ^= 0xff;
-    assert!(alice_pk.verify(&bad, &alice_sig).is_err());
+    assert!(alice_pk.verify(&bad, alice_sig).is_err());
   }
 }
diff --git a/pkgs/pkc/src/ecdsa/secret_ops.rs b/pkgs/pkc/src/ecdsa/secret_ops.rs
index 248f44e5..6416f186 100644
--- a/pkgs/pkc/src/ecdsa/secret_ops.rs
+++ b/pkgs/pkc/src/ecdsa/secret_ops.rs
@@ -605,7 +605,7 @@ mod tests {
   #[rstest]
   fn sign_verify_roundtrip(alice_sk: EcdsaSecretKey) {
     let sig = alice_sk.sign(&MSG);
-    assert!(alice_sk.public_key().verify(&MSG, &sig).is_ok());
+    assert!(alice_sk.public_key().verify(&MSG, sig).is_ok());
   }
 
   #[rstest]
@@ -624,6 +624,6 @@ mod tests {
   fn verify_rejects_wrong_key(alice_sk: EcdsaSecretKey, bob_sk: EcdsaSecretKey) {
     assert!(!alice_sk.verify_pubkey(&bob_sk.public_key()));
     let sig = alice_sk.sign(&MSG);
-    assert!(bob_sk.public_key().verify(&MSG, &sig).is_err());
+    assert!(bob_sk.public_key().verify(&MSG, sig).is_err());
   }
 }
diff --git a/pkgs/pkc/src/ecdsa/sig_ops.rs b/pkgs/pkc/src/ecdsa/sig_ops.rs
index ad207f22..46e76b24 100644
--- a/pkgs/pkc/src/ecdsa/sig_ops.rs
+++ b/pkgs/pkc/src/ecdsa/sig_ops.rs
@@ -22,7 +22,7 @@ use secp256k1::ecdsa::{SerializedSignature, Signature};
 use core::hash::{Hash, Hasher};
 
 /// An ECDSA signature (64-byte compact r||s).
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "codec", derive(TypeId))]
 #[cfg_attr(feature = "serde", derive(::serde::Serialize, ::serde::Deserialize))]
 #[cfg_attr(
@@ -220,7 +220,7 @@ mod tests {
     let normalized = high_sig.normalize_s().unwrap();
     assert!(normalized.is_low_s());
     assert_eq!(normalized, alice_sig);
-    assert!(alice_pk.verify(&MSG, &normalized).is_ok());
+    assert!(alice_pk.verify(&MSG, normalized).is_ok());
   }
 
   #[cfg(feature = "serde")]
diff --git a/pkgs/pkc/src/ecdsa/sig_rec_ops.rs b/pkgs/pkc/src/ecdsa/sig_rec_ops.rs
index e7193b84..2648484b 100644
--- a/pkgs/pkc/src/ecdsa/sig_rec_ops.rs
+++ b/pkgs/pkc/src/ecdsa/sig_rec_ops.rs
@@ -20,7 +20,7 @@ use dash_types::{dlgt_codec, type_id::TypeId};
 use secp256k1::ecdsa::{RecoveryId, Signature};
 
 /// An ECDSA signature with recovery id and compression metadata.
-#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 #[cfg_attr(feature = "codec", derive(TypeId))]
 #[cfg_attr(feature = "serde", derive(::serde::Serialize, ::serde::Deserialize))]
 #[cfg_attr(feature = "serde", serde(into = "EcdsaRecSigBytes", try_from = "EcdsaRecSigBytes"))]
@@ -104,7 +104,7 @@ type_cvrt!(From<EcdsaRecSignature> for EcdsaRecSigBytes, |rec| {
 });
 
 type_cvrt!(From<EcdsaRecSignature> for EcdsaSignature, |rec| {
-  rec.signature().clone()
+  *rec.signature()
 });
 
 type_cvrt!(TryFrom<EcdsaRecSigBytes> for EcdsaRecSignature, EcdsaError, |bytes| {
@@ -147,14 +147,14 @@ mod tests {
   fn conversions_commute(alice_rec_sig: EcdsaRecSignature) {
     // Both paths to the plain bag must agree: drop metadata then serialize, or
     // serialize then strip the header.
-    let via_ops = EcdsaSigBytes::from(EcdsaSignature::from(alice_rec_sig.clone()));
+    let via_ops = EcdsaSigBytes::from(EcdsaSignature::from(alice_rec_sig));
     let via_bag = EcdsaSigBytes::from(EcdsaRecSigBytes::from(&alice_rec_sig));
     assert_eq!(via_ops, via_bag);
   }
 
   #[rstest]
   fn from_parts_rejects_out_of_range_id(alice_sig: EcdsaSignature) {
-    assert!(EcdsaRecSignature::from_parts(alice_sig.clone(), 4, Compression::Compressed).is_err());
+    assert!(EcdsaRecSignature::from_parts(alice_sig, 4, Compression::Compressed).is_err());
     assert!(EcdsaRecSignature::from_parts(alice_sig, 255, Compression::Compressed).is_err());
   }
 
@@ -201,7 +201,7 @@ mod tests {
 
   #[rstest]
   fn verifies_without_downcast(alice_pk: EcdsaPublicKey, alice_rec_sig: EcdsaRecSignature) {
-    assert!(alice_pk.verify(&MSG, &alice_rec_sig).is_ok());
+    assert!(alice_pk.verify(&MSG, alice_rec_sig).is_ok());
     assert!(alice_pk.verify(&MSG, alice_rec_sig.signature()).is_ok());
   }
 

From 2d4ab0f285ae018ac9065d1b192a6bc5aac28362 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 17 Sep 2026 17:53:15 +0530
Subject: [PATCH 4/7] pkc%feat(bls): derive `Copy` for
 `Bls{PublicKey,Signature}<S>`

---
 maint/codeql/rust/pkc.model.yml |  4 +---
 pkgs/pkc/src/bls/ies_ops.rs     | 12 ++++++------
 pkgs/pkc/src/bls/public_ops.rs  |  4 +++-
 pkgs/pkc/src/bls/scheme_ops.rs  |  4 ++--
 pkgs/pkc/src/bls/share_ops.rs   |  4 ++--
 pkgs/pkc/src/bls/sig_basic.rs   |  4 +++-
 6 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/maint/codeql/rust/pkc.model.yml b/maint/codeql/rust/pkc.model.yml
index 75af2e34..4c9342c0 100644
--- a/maint/codeql/rust/pkc.model.yml
+++ b/maint/codeql/rust/pkc.model.yml
@@ -67,6 +67,4 @@ extensions:
   - addsTo:
       pack: base-sdk/codeql-rust
       extensible: armLacksTrait
-    data:
-      - ["Bls", "PublicKey", "Copy"]
-      - ["Bls", "Signature", "Copy"]
+    data: []
diff --git a/pkgs/pkc/src/bls/ies_ops.rs b/pkgs/pkc/src/bls/ies_ops.rs
index cb5b3df1..1868e45c 100644
--- a/pkgs/pkc/src/bls/ies_ops.rs
+++ b/pkgs/pkc/src/bls/ies_ops.rs
@@ -141,7 +141,7 @@ impl<S: BlsScheme> BlsIesBlob<S> {
 impl<S: BlsScheme> Clone for BlsIesBlob<S> {
   fn clone(&self) -> Self {
     Self {
-      ephemeral_pk: self.ephemeral_pk.clone(),
+      ephemeral_pk: self.ephemeral_pk,
       iv_seed: self.iv_seed,
       data: self.data.clone(),
     }
@@ -241,7 +241,7 @@ impl<S: BlsScheme> BlsIesMulti<S> {
   /// recipient index.
   pub fn to_blob(&self, index: usize) -> Option<BlsIesBlob<S>> {
     Some(BlsIesBlob::new(
-      self.ephemeral_pk.clone(),
+      self.ephemeral_pk,
       self.iv_seed,
       self.blobs.get(index)?.clone(),
     ))
@@ -261,7 +261,7 @@ impl<S: BlsScheme> BlsIesMulti<S> {
 impl<S: BlsScheme> Clone for BlsIesMulti<S> {
   fn clone(&self) -> Self {
     Self {
-      ephemeral_pk: self.ephemeral_pk.clone(),
+      ephemeral_pk: self.ephemeral_pk,
       iv_seed: self.iv_seed,
       blobs: self.blobs.clone(),
     }
@@ -486,7 +486,7 @@ mod tests {
     /// The multi-recipient message the vectors record.
     fn message(&self) -> BlsIesMulti<S> {
       BlsIesMulti::new(
-        self.eph_pk.clone(),
+        self.eph_pk,
         self.iv_seed,
         self.recipients.iter().map(|r| vec_from_hex(&r.ciphertext)).collect(),
       )
@@ -710,9 +710,9 @@ mod tests {
     let kat = load_kat::<BlsScIetf>("ietf");
     let misaligned = vec![0u8; 17];
 
-    let blob = BlsIesBlob::new(kat.eph_pk.clone(), kat.iv_seed, misaligned.clone());
+    let blob = BlsIesBlob::new(kat.eph_pk, kat.iv_seed, misaligned.clone());
     assert_eq!(blob.data(), misaligned);
-    assert!(BlsIesMulti::new(kat.eph_pk.clone(), kat.iv_seed, vec![misaligned.clone()]).is_ok());
+    assert!(BlsIesMulti::new(kat.eph_pk, kat.iv_seed, vec![misaligned.clone()]).is_ok());
 
     let bag = BlsIesBlobBytes::new(BlsPkBytes::from(&kat.eph_pk), kat.iv_seed, misaligned.clone());
     assert_eq!(BlsIesBlob::<BlsScIetf>::try_from(&bag).unwrap().data(), misaligned);
diff --git a/pkgs/pkc/src/bls/public_ops.rs b/pkgs/pkc/src/bls/public_ops.rs
index 6b03e0a7..391a0f76 100644
--- a/pkgs/pkc/src/bls/public_ops.rs
+++ b/pkgs/pkc/src/bls/public_ops.rs
@@ -140,10 +140,12 @@ impl BlsPublicKey<BlsScIetf> {
 
 impl<S: BlsScheme> Clone for BlsPublicKey<S> {
   fn clone(&self) -> Self {
-    Self(self.0.clone())
+    *self
   }
 }
 
+impl<S: BlsScheme> Copy for BlsPublicKey<S> {}
+
 impl<S: BlsScheme> Debug for BlsPublicKey<S> {
   fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
     qtypestr(f, type_name::<Self>())?;
diff --git a/pkgs/pkc/src/bls/scheme_ops.rs b/pkgs/pkc/src/bls/scheme_ops.rs
index ebef4dda..bf892ab1 100644
--- a/pkgs/pkc/src/bls/scheme_ops.rs
+++ b/pkgs/pkc/src/bls/scheme_ops.rs
@@ -49,9 +49,9 @@ pub trait BlsScheme: BlsSchemeId + sealed::Sealed + Sized {
   /// Inner secret key representation.
   type InnerSk: Clone + Send + Sync;
   /// Inner public key representation.
-  type InnerPk: Clone + Debug + PartialEq + Eq + Send + Sync;
+  type InnerPk: Copy + Debug + PartialEq + Eq + Send + Sync;
   /// Inner signature representation.
-  type InnerSig: Clone + Debug + PartialEq + Eq + Send + Sync;
+  type InnerSig: Copy + Debug + PartialEq + Eq + Send + Sync;
   /// Message type accepted by signing and verification.
   type Msg: ?Sized;
 
diff --git a/pkgs/pkc/src/bls/share_ops.rs b/pkgs/pkc/src/bls/share_ops.rs
index 3f47c85d..692bff6b 100644
--- a/pkgs/pkc/src/bls/share_ops.rs
+++ b/pkgs/pkc/src/bls/share_ops.rs
@@ -100,7 +100,7 @@ impl<S: BlsScheme> Clone for BlsSigShare<S> {
   fn clone(&self) -> Self {
     Self {
       id: self.id,
-      sig: self.sig.clone(),
+      sig: self.sig,
     }
   }
 }
@@ -157,7 +157,7 @@ impl<S: BlsScheme> Clone for BlsPkShare<S> {
   fn clone(&self) -> Self {
     Self {
       id: self.id,
-      pk: self.pk.clone(),
+      pk: self.pk,
     }
   }
 }
diff --git a/pkgs/pkc/src/bls/sig_basic.rs b/pkgs/pkc/src/bls/sig_basic.rs
index f8c26444..3197048c 100644
--- a/pkgs/pkc/src/bls/sig_basic.rs
+++ b/pkgs/pkc/src/bls/sig_basic.rs
@@ -74,10 +74,12 @@ impl<S: BlsScheme> BlsSignature<S> {
 
 impl<S: BlsScheme> Clone for BlsSignature<S> {
   fn clone(&self) -> Self {
-    Self(self.0.clone())
+    *self
   }
 }
 
+impl<S: BlsScheme> Copy for BlsSignature<S> {}
+
 impl<S: BlsScheme> Debug for BlsSignature<S> {
   fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
     qtypestr(f, core::any::type_name::<Self>())?;

From 358d7a881c7b6a1b7563e866a12bc5c94f0f359b Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 17 Sep 2026 17:55:27 +0530
Subject: [PATCH 5/7] pkc%chore: re-export crates surfaced by the public API

---
 maint/codeql/rust/lib/imports.qll | 20 ++++++++++++++++++++
 pkgs/num/src/lib.rs               |  1 +
 pkgs/pkc/src/lib.rs               | 17 +++++++++++++++++
 pkgs/types/src/lib.rs             |  1 +
 4 files changed, 39 insertions(+)

diff --git a/maint/codeql/rust/lib/imports.qll b/maint/codeql/rust/lib/imports.qll
index 0aa7365e..cf8c747b 100644
--- a/maint/codeql/rust/lib/imports.qll
+++ b/maint/codeql/rust/lib/imports.qll
@@ -74,6 +74,26 @@ private predicate isAllowlistedReexport(Use u) {
     u.getUseTree().getPath().getSegment().getIdentifier().getText() = "Numeric"
   )
   or
+  fileOf(u).getAbsolutePath().matches("%pkgs/pkc/%") and
+  (
+    // Crate emits types relying on types or traits defined by a dependency, part of public API
+    usePrefix(u) = "blst"
+    or
+    usePrefix(u) = "dash_num"
+    or
+    usePrefix(u) = "dash_types"
+    or
+    usePrefix(u) = "ff"
+    or
+    usePrefix(u) = "group"
+    or
+    usePrefix(u) = "rand_core"
+    or
+    usePrefix(u) = "subtle"
+    or
+    usePrefix(u) = "zeroize"
+  )
+  or
   fileOf(u).getAbsolutePath().matches("%pkgs/script/%") and
   (
     // Workaround for the orphan rule, not part of public API
diff --git a/pkgs/num/src/lib.rs b/pkgs/num/src/lib.rs
index c319a6dc..ce7949e6 100644
--- a/pkgs/num/src/lib.rs
+++ b/pkgs/num/src/lib.rs
@@ -33,4 +33,5 @@ pub use crate::arith256::Arith256;
 pub use crate::compact::{CompactTarget, DecodedTarget};
 pub use crate::hash::{Hash160, Hash256, HashBlob, ParseHexError};
 
+// TODO(kwvg): move to mod __deps with crate-level export
 pub use dash_types::Numeric;
diff --git a/pkgs/pkc/src/lib.rs b/pkgs/pkc/src/lib.rs
index 26938faf..9d982e14 100644
--- a/pkgs/pkc/src/lib.rs
+++ b/pkgs/pkc/src/lib.rs
@@ -20,6 +20,23 @@ mod prelude;
 pub mod bls;
 pub mod ecdsa;
 
+#[doc(hidden)]
+pub mod __deps {
+  #[cfg(feature = "bls")]
+  pub use blst;
+  pub use dash_num;
+  pub use dash_types;
+  #[cfg(feature = "bls")]
+  pub use ff;
+  #[cfg(feature = "bls")]
+  pub use group;
+  #[cfg(any(feature = "bls", feature = "ecdsa"))]
+  pub use rand_core;
+  #[cfg(feature = "bls")]
+  pub use subtle;
+  pub use zeroize;
+}
+
 #[cfg(feature = "codec")]
 #[doc(hidden)]
 pub mod __private {
diff --git a/pkgs/types/src/lib.rs b/pkgs/types/src/lib.rs
index fb283584..d09a19a3 100644
--- a/pkgs/types/src/lib.rs
+++ b/pkgs/types/src/lib.rs
@@ -28,6 +28,7 @@ pub use crate::macros::qtypestr;
 pub use crate::numeric::Numeric;
 pub use crate::traits::{Checkable, Hashable};
 
+// TODO(kwvg): move to mod __deps
 pub use zeroize;
 
 cfg_if::cfg_if! {

From 8b73c47e1ca7de0024e7d2b36b3faa0a043d8b18 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 17 Sep 2026 17:57:13 +0530
Subject: [PATCH 6/7] pkc%feat(ecdsa): define conversions to/from underlying
 types

---
 maint/codeql/rust/lib/imports.qll | 22 ++++++++------
 pkgs/pkc/src/ecdsa/public_ops.rs  | 24 ++++++++++++++++
 pkgs/pkc/src/ecdsa/secret_ops.rs  | 19 ++++++++++++
 pkgs/pkc/src/ecdsa/sig_ops.rs     | 15 ++++++++++
 pkgs/pkc/src/ecdsa/sig_rec_ops.rs | 48 +++++++++++++++++++++++++++++--
 pkgs/pkc/src/lib.rs               |  2 ++
 6 files changed, 120 insertions(+), 10 deletions(-)

diff --git a/maint/codeql/rust/lib/imports.qll b/maint/codeql/rust/lib/imports.qll
index cf8c747b..218c51d8 100644
--- a/maint/codeql/rust/lib/imports.qll
+++ b/maint/codeql/rust/lib/imports.qll
@@ -53,17 +53,20 @@ predicate isPublicMod(Module m) {
   not exists(m.getVisibility().getPath())
 }
 
+/** Holds if `u` sits directly inside the crate-root module `name`. */
+private predicate isInRootModule(Use u, string name) {
+  exists(Module m |
+    m.getName().getText() = name and
+    u.getParentNode() = m.getItemList() and
+    isRootModule(m)
+  )
+}
+
 /**
  * Holds if `u` lives inside a crate-root `__private` module
  * (intentional crate-level re-exports for macro support).
  */
-predicate isMacroReexport(Use u) {
-  exists(Module priv |
-    priv.getName().getText() = "__private" and
-    u.getParentNode() = priv.getItemList() and
-    isRootModule(priv)
-  )
-}
+predicate isMacroReexport(Use u) { isInRootModule(u, "__private") }
 
 /** Holds if `u` is an allowlisted re-export from a foreign crate. */
 private predicate isAllowlistedReexport(Use u) {
@@ -75,8 +78,9 @@ private predicate isAllowlistedReexport(Use u) {
   )
   or
   fileOf(u).getAbsolutePath().matches("%pkgs/pkc/%") and
+  // Crate emits types relying on types or traits defined by a dependency, part of public API
+  isInRootModule(u, "__deps") and
   (
-    // Crate emits types relying on types or traits defined by a dependency, part of public API
     usePrefix(u) = "blst"
     or
     usePrefix(u) = "dash_num"
@@ -89,6 +93,8 @@ private predicate isAllowlistedReexport(Use u) {
     or
     usePrefix(u) = "rand_core"
     or
+    usePrefix(u) = "secp256k1"
+    or
     usePrefix(u) = "subtle"
     or
     usePrefix(u) = "zeroize"
diff --git a/pkgs/pkc/src/ecdsa/public_ops.rs b/pkgs/pkc/src/ecdsa/public_ops.rs
index 50247a7c..7d96b91f 100644
--- a/pkgs/pkc/src/ecdsa/public_ops.rs
+++ b/pkgs/pkc/src/ecdsa/public_ops.rs
@@ -267,6 +267,14 @@ type_cvrt!(TryFrom<EcdsaPkBytes> for EcdsaPublicKey, EcdsaError, |bytes| {
   Self::from_bytes(bytes.as_bytes())
 });
 
+type_cvrt!(From<EcdsaPublicKey> for PublicKey, |pk| {
+  pk.inner
+});
+
+type_cvrt!(From<PublicKey> for EcdsaPublicKey, |inner| {
+  Self::from_inner(*inner, Compression::Compressed)
+});
+
 #[cfg(test)]
 #[expect(clippy::unwrap_used, reason = "test code")]
 mod tests {
@@ -292,6 +300,22 @@ mod tests {
     pk: String,
   }
 
+  #[rstest]
+  fn backend_roundtrip_keeps_point_and_defaults_to_compressed(alice_pk: EcdsaPublicKey) {
+    let inner = secp256k1::PublicKey::from(&alice_pk);
+    assert_eq!(inner.serialize(), alice_pk.to_compressed());
+
+    let mut lifted = EcdsaPublicKey::from(inner);
+    assert!(lifted.is_compressed());
+    assert_eq!(lifted, alice_pk);
+    lifted.decompress();
+    assert_eq!(
+      secp256k1::PublicKey::from(&lifted),
+      inner,
+      "the form does not touch the point"
+    );
+  }
+
   #[rstest]
   fn compressed_roundtrip(alice_pk: EcdsaPublicKey) {
     let bytes = alice_pk.to_compressed();
diff --git a/pkgs/pkc/src/ecdsa/secret_ops.rs b/pkgs/pkc/src/ecdsa/secret_ops.rs
index 6416f186..7d4f11d1 100644
--- a/pkgs/pkc/src/ecdsa/secret_ops.rs
+++ b/pkgs/pkc/src/ecdsa/secret_ops.rs
@@ -333,6 +333,14 @@ type_cvrt!(TryFrom<EcdsaSkBytes> for EcdsaSecretKey, EcdsaError, |bytes| {
   Self::from_bytes(bytes.as_bytes(), Compression::from(bytes.is_compressed()))
 });
 
+type_cvrt!(From<EcdsaSecretKey> for SecretKey, |sk| {
+  sk.inner
+});
+
+type_cvrt!(From<SecretKey> for EcdsaSecretKey, |inner| {
+  Self::from_inner(*inner, Compression::Compressed)
+});
+
 #[cfg(test)]
 #[expect(clippy::ptr_arg, clippy::unwrap_used, reason = "test code")]
 mod tests {
@@ -626,4 +634,15 @@ mod tests {
     let sig = alice_sk.sign(&MSG);
     assert!(bob_sk.public_key().verify(&MSG, sig).is_err());
   }
+
+  #[rstest]
+  fn backend_roundtrip_keeps_scalar_and_defaults_to_compressed(alice_sk: EcdsaSecretKey) {
+    let inner = secp256k1::SecretKey::from(&alice_sk);
+    assert_eq!(inner.to_secret_bytes(), *alice_sk.to_bytes());
+
+    let lifted = EcdsaSecretKey::from(inner);
+    assert!(lifted.is_compressed());
+    assert_eq!(lifted, alice_sk);
+    assert!(lifted.verify_pubkey(&alice_sk.public_key()));
+  }
 }
diff --git a/pkgs/pkc/src/ecdsa/sig_ops.rs b/pkgs/pkc/src/ecdsa/sig_ops.rs
index 46e76b24..5d3497e1 100644
--- a/pkgs/pkc/src/ecdsa/sig_ops.rs
+++ b/pkgs/pkc/src/ecdsa/sig_ops.rs
@@ -159,6 +159,14 @@ type_cvrt!(TryFrom<EcdsaSigBytes> for EcdsaSignature, EcdsaError, |bytes| {
   Self::from_bytes(bytes.as_bytes())
 });
 
+type_cvrt!(From<EcdsaSignature> for Signature, |sig| {
+  sig.0
+});
+
+type_cvrt!(From<Signature> for EcdsaSignature, |inner| {
+  Self(*inner)
+});
+
 #[cfg(test)]
 #[expect(clippy::unwrap_used, reason = "test code")]
 mod tests {
@@ -228,4 +236,11 @@ mod tests {
   fn serde_sig_roundtrip(alice_sig: EcdsaSignature) {
     assert_json_rt(&alice_sig);
   }
+
+  #[rstest]
+  fn backend_roundtrip(alice_sig: EcdsaSignature) {
+    let inner = secp256k1::ecdsa::Signature::from(&alice_sig);
+    assert_eq!(inner.serialize_compact(), alice_sig.to_bytes());
+    assert_eq!(EcdsaSignature::from(inner), alice_sig);
+  }
 }
diff --git a/pkgs/pkc/src/ecdsa/sig_rec_ops.rs b/pkgs/pkc/src/ecdsa/sig_rec_ops.rs
index 2648484b..076f7b9e 100644
--- a/pkgs/pkc/src/ecdsa/sig_rec_ops.rs
+++ b/pkgs/pkc/src/ecdsa/sig_rec_ops.rs
@@ -17,7 +17,7 @@ use dash_num::Hash256;
 use dash_types::type_cvrt;
 #[cfg(feature = "codec")]
 use dash_types::{dlgt_codec, type_id::TypeId};
-use secp256k1::ecdsa::{RecoveryId, Signature};
+use secp256k1::ecdsa::{RecoverableSignature, RecoveryId, Signature};
 
 /// An ECDSA signature with recovery id and compression metadata.
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
@@ -114,11 +114,26 @@ type_cvrt!(TryFrom<EcdsaRecSigBytes> for EcdsaRecSignature, EcdsaError, |bytes|
   })
 });
 
+type_cvrt!(TryFrom<EcdsaRecSignature> for RecoverableSignature, EcdsaError, |rec| {
+  RecoverableSignature::from_compact(&rec.to_compact(), rec.backend_recovery_id())
+    .map_err(|_| EcdsaError::InvalidSignature)
+});
+
+// The backend type holds only the scalars and the recovery id, the compression
+// flag doesn't make it through and it is assumed to be compressed. To preserve
+// the compression flag, use `from_parts`.
+type_cvrt!(From<RecoverableSignature> for EcdsaRecSignature, |rec| {
+  let (rid, _) = rec.serialize_compact();
+  Self::from_inner(rec.to_standard(), rid, Compression::Compressed)
+});
+
 #[cfg(test)]
 #[expect(clippy::unwrap_used, reason = "test code")]
 mod tests {
   use crate::ecdsa::tests::*;
-  use crate::ecdsa::{Compression, EcdsaPublicKey, EcdsaRecSigBytes, EcdsaRecSignature, EcdsaSigBytes, EcdsaSignature};
+  use crate::ecdsa::{
+    Compression, EcdsaPublicKey, EcdsaRecSigBytes, EcdsaRecSignature, EcdsaSecretKey, EcdsaSigBytes, EcdsaSignature,
+  };
 
   #[cfg(feature = "serde")]
   use dash_dev::assert_json_rt;
@@ -210,4 +225,33 @@ mod tests {
   fn serde_roundtrip(alice_rec_sig: EcdsaRecSignature) {
     assert_json_rt(&alice_rec_sig);
   }
+
+  #[rstest]
+  fn uncompressed_recsig_keeps_flag() {
+    let sk = EcdsaSecretKey::from_bytes(&ALICE_SK, Compression::Uncompressed).unwrap();
+    let rec = sk.sign_recoverable(&MSG);
+    assert!(!rec.is_compressed());
+
+    // Recovery carries the flag onto the key it rebuilds.
+    let pk = EcdsaPublicKey::recover(&MSG, &rec).unwrap();
+    assert!(!pk.is_compressed());
+    assert_eq!(pk, sk.public_key());
+
+    // The backend type doesn't store the flag, so the round trip comes back
+    // compressed.
+    let inner = secp256k1::ecdsa::RecoverableSignature::try_from(&rec).unwrap();
+    let back = EcdsaRecSignature::from(inner);
+    assert_eq!(back.signature(), rec.signature());
+    assert_eq!(back.recovery_id(), rec.recovery_id());
+    assert!(back.is_compressed());
+  }
+
+  #[rstest]
+  fn backend_roundtrip_keeps_recovery_id(alice_rec_sig: EcdsaRecSignature) {
+    let inner = secp256k1::ecdsa::RecoverableSignature::try_from(&alice_rec_sig).unwrap();
+    let (rid, compact) = inner.serialize_compact();
+    assert_eq!(compact, alice_rec_sig.to_compact());
+    assert_eq!(rid.to_u8(), alice_rec_sig.recovery_id());
+    assert_eq!(EcdsaRecSignature::from(inner), alice_rec_sig);
+  }
 }
diff --git a/pkgs/pkc/src/lib.rs b/pkgs/pkc/src/lib.rs
index 9d982e14..eeae04c7 100644
--- a/pkgs/pkc/src/lib.rs
+++ b/pkgs/pkc/src/lib.rs
@@ -32,6 +32,8 @@ pub mod __deps {
   pub use group;
   #[cfg(any(feature = "bls", feature = "ecdsa"))]
   pub use rand_core;
+  #[cfg(feature = "ecdsa")]
+  pub use secp256k1;
   #[cfg(feature = "bls")]
   pub use subtle;
   pub use zeroize;

From 98e0c14585900e582535f311a7949718358e75d4 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 17 Sep 2026 18:00:12 +0530
Subject: [PATCH 7/7] pkc%refac(ecdsa): return version prefix with `from_wif`

---
 pkgs/pkc/src/ecdsa/secret_bytes.rs | 61 +++++++++++++-----------------
 1 file changed, 27 insertions(+), 34 deletions(-)

diff --git a/pkgs/pkc/src/ecdsa/secret_bytes.rs b/pkgs/pkc/src/ecdsa/secret_bytes.rs
index f0595df9..4277a87b 100644
--- a/pkgs/pkc/src/ecdsa/secret_bytes.rs
+++ b/pkgs/pkc/src/ecdsa/secret_bytes.rs
@@ -51,26 +51,23 @@ impl EcdsaSkBytes {
   }
 
   #[cfg(feature = "codec")]
-  /// Decode a wallet import format-encoded private key.
+  /// Decode a wallet import format-encoded private key, returning the key
+  /// and the version prefix it was encoded under.
   ///
-  /// Returns `None` on a bad checksum, an unexpected version prefix, a length
-  /// outside 33 or 34 bytes, a malformed compression flag, or an all-zero
-  /// scalar. Scalars at or above the curve order still pass: range checking
-  /// belongs to [`EcdsaSecretKey`](crate::ecdsa::EcdsaSecretKey).
-  pub fn from_wif(s: &str, prefix: u8) -> Option<Self> {
+  /// Returns `None` on a bad checksum, a length outside 33 or 34 bytes, a
+  /// malformed compression flag, or an all-zero scalar. Scalars at or above the
+  /// curve order still pass: range checking belongs to
+  /// [`EcdsaSecretKey`](crate::ecdsa::EcdsaSecretKey).
+  pub fn from_wif(s: &str) -> Option<(Self, u8)> {
     let data = Zeroizing::new(decode_check(s).ok()?);
-    let result = match data.len() {
-      33 if data[0] == prefix => {
-        let key: [u8; ECDSA_SK_LEN] = data[1..33].try_into().ok()?;
-        Some(Self::from_bytes(key, Compression::Uncompressed))
-      }
-      34 if data[0] == prefix && data[33] == 0x01 => {
-        let key: [u8; ECDSA_SK_LEN] = data[1..33].try_into().ok()?;
-        Some(Self::from_bytes(key, Compression::Compressed))
-      }
-      _ => None,
+    let compressed = match data.len() {
+      33 => Compression::Uncompressed,
+      34 if data[33] == 0x01 => Compression::Compressed,
+      _ => return None,
     };
-    result.filter(|sk| !sk.is_null())
+    let key: [u8; ECDSA_SK_LEN] = data[1..33].try_into().ok()?;
+    let sk = Self::from_bytes(key, compressed);
+    (!sk.is_null()).then_some((sk, data[0]))
   }
 
   /// Copy out the raw inner bytes.
@@ -149,13 +146,15 @@ mod tests {
   }
 
   #[rstest]
-  #[case::compressed(Compression::Compressed)]
-  #[case::uncompressed(Compression::Uncompressed)]
-  fn wif_roundtrip(#[case] compressed: Compression) {
+  #[case::compressed(Compression::Compressed, 0x80)]
+  #[case::uncompressed(Compression::Uncompressed, 0x80)]
+  #[case::other_prefix(Compression::Compressed, 0xcc)]
+  fn wif_roundtrip(#[case] compressed: Compression, #[case] prefix: u8) {
     let sk = EcdsaSkBytes::from_bytes([0x11u8; ECDSA_SK_LEN], compressed);
-    let wif = sk.to_wif(0x80).unwrap();
-    let restored = EcdsaSkBytes::from_wif(&wif, 0x80).unwrap();
+    let wif = sk.to_wif(prefix).unwrap();
+    let (restored, found) = EcdsaSkBytes::from_wif(&wif).unwrap();
     assert_eq!(restored, sk);
+    assert_eq!(found, prefix, "prefix preserved");
   }
 
   /// The encoder must not emit a string the decoder refuses to read back.
@@ -183,11 +182,6 @@ mod tests {
     base58ck::encode(&raw)
   }
 
-  fn wif_wrong_prefix() -> String {
-    let sk = EcdsaSkBytes::from_bytes([0x33u8; ECDSA_SK_LEN], Compression::Compressed);
-    (*sk.to_wif(0x80).unwrap()).clone()
-  }
-
   fn wif_wrong_length() -> String {
     base58ck::encode_check(&[0x80u8; 32])
   }
@@ -201,12 +195,11 @@ mod tests {
   }
 
   #[rstest]
-  #[case::zero_key(wif_zero_key(), 0x80)]
-  #[case::bad_checksum(wif_bad_checksum(), 0x80)]
-  #[case::wrong_prefix(wif_wrong_prefix(), 0xef)]
-  #[case::wrong_length(wif_wrong_length(), 0x80)]
-  #[case::bad_compression_byte(wif_bad_compression_byte(), 0x80)]
-  fn wif_rejects(#[case] wif: String, #[case] prefix: u8) {
-    assert!(EcdsaSkBytes::from_wif(&wif, prefix).is_none());
+  #[case::zero_key(wif_zero_key())]
+  #[case::bad_checksum(wif_bad_checksum())]
+  #[case::wrong_length(wif_wrong_length())]
+  #[case::bad_compression_byte(wif_bad_compression_byte())]
+  fn wif_rejects(#[case] wif: String) {
+    assert!(EcdsaSkBytes::from_wif(&wif).is_none());
   }
 }