Tracking PR fo v0.21.0 release

.github/workflows/fuzz.yml

@@ -0,0 +1,61 @@
+# Runs fuzz targets with short execution time for CI smoke testing.
+# This is not a replacement for dedicated fuzzing runs, but catches obvious regressions.
+# Runs on a schedule (daily) rather than every PR to save CI resources.
+
+name: fuzz
+
+concurrency:
+  group: "${{ github.workflow }} @ ${{ github.event.pull_request.head.label || github.head_ref || github.ref }}"
+  cancel-in-progress: true
+
+on:
+  schedule:
+    # Run daily at 2 AM UTC
+    - cron: '0 2 * * *'
+  workflow_dispatch:  # Allow manual triggering
+
+permissions:
+  contents: read
+
+jobs:
+  fuzz-miden-serde-utils:
+    name: fuzz miden-serde-utils (${{ matrix.target }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        target: [primitives, collections, string, vint64, goldilocks, budgeted]
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@main
+      - name: Cleanup large tools for build space
+        uses: ./.github/actions/cleanup-runner
+      - uses: Swatinem/rust-cache@v2
+      - name: Install cargo-fuzz
+        run: cargo install cargo-fuzz --locked
+      - name: Run fuzz target (smoke test)
+        working-directory: miden-serde-utils
+        run: |
+          cargo fuzz run ${{ matrix.target }} -- -max_total_time=60 -runs=10000
+
+  fuzz-miden-crypto:
+    name: fuzz miden-crypto (${{ matrix.target }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        target: [word, merkle, smt_serde]
+    timeout-minutes: 15
+    steps:
+      - uses: actions/checkout@main
+      - name: Cleanup large tools for build space
+        uses: ./.github/actions/cleanup-runner
+      - uses: Swatinem/rust-cache@v2
+      - name: Install cargo-fuzz
+        run: cargo install cargo-fuzz --locked
+      - name: Run fuzz target (smoke test)
+        run: |
+          # Build the fuzz target first
+          cargo fuzz build --fuzz-dir miden-crypto-fuzz ${{ matrix.target }}
+          # Run directly to avoid cargo-fuzz wrapper SIGPIPE issue
+          miden-crypto-fuzz/target/x86_64-unknown-linux-gnu/release/${{ matrix.target }} -max_total_time=60 -runs=10000

CHANGELOG.md

@@ -1,3 +1,14 @@
+## 0.21.0 (2026-01-14)
+
+- Use more idiomatic Plonky3 APIs ([#743](https://github.com/0xMiden/crypto/pull/743)).
+- [BREAKING] Removed `p3-compat` and `winter-compat` features ([#745](https://github.com/0xMiden/crypto/pull/745)).
+- Made concurrent feature interact with plonky3's parallel features, replace homegrown iterator macros with p3-maybe-rayon ([#749](https://github.com/0xMiden/crypto/pull/749)).
+- Reduced dependency on std in tests, add test helpers to access Rngs in no-std contexts ([#752](https://github.com/0xMiden/crypto/pull/752)).
+- [BREAKING] Changed sponge state layout from `[CAPACITY, RATE1, RATE0]` (BE) to `[RATE0, RATE1, CAPACITY]` (LE) ([#755](https://github.com/0xMiden/crypto/pull/755)).
+- [BREAKING] Added length-prefixing to Serializable/Deserializable impls for collections, fuzz deserialization for panics ([#757](https://github.com/0xMiden/crypto/pull/757)).
+- Added `SmtLeaf::try_from_elements()` ([#773](https://github.com/0xMiden/crypto/pull/773)).
+- Copied `WordWrapper` macro from `miden-base` to `miden-crypto-derive`.
+
 # 0.20.1 (2025-12-29)
 
 - Added more re-exports from Plonky3 dependencies ([#741](https://github.com/0xMiden/crypto/pull/741)).