Publishing v0.4.1 (#136 )

v0.4.1 - draft-11 compatible, builds on latest Rust (#135 )
* Fix Clippy (#85) * Update `curve25519-dalek` to 4.0.0-pre.5 (#86) * Update `curve25519-dalek` * Improve documentation * Adding all-features CI test (#87) * Upgrade `p256` to v0.12 (#90) * Upgrade `p256` to v0.12 * Upgrade MSRV to 1.60 (cherry picked from commit daa8dc048f) * Replace `json` with `serde_json` (#92) (cherry picked from commit c8de51672b) * Fix Clippy (#96) (cherry picked from commit 74eaebe446) * Depend on `ProjectivePoint: ToEncodedPoint` (#95) (cherry picked from commit 0409db6f40) * Update `curve25519-dalek` (#94) (cherry picked from commit 2787151e1d) * Use explicit crate features (#100) (cherry picked from commit 5bce3e3206) * Bump `curve25519-dalek` to v4.0.0-rc.1 (#102) (cherry picked from commit 8363d26f6f) * Test P-384 (#84) (cherry picked from commit 83eb78b232) * Update RustCrypto dependencies to v0.13 (#106) (cherry picked from commit 8b895cc631) * Update curve25519-dalek requirement from =4.0.0-rc.1 to =4.0.0-rc.2 (#108) Updates the requirements on [curve25519-dalek](https://github.com/dalek-cryptography/curve25519-dalek) to permit the latest version. - [Release notes](https://github.com/dalek-cryptography/curve25519-dalek/releases) - [Changelog](https://github.com/dalek-cryptography/curve25519-dalek/blob/main/CHANGELOG.md) - [Commits](https://github.com/dalek-cryptography/curve25519-dalek/compare/4.0.0-rc.1...4.0.0-rc.2) --- updated-dependencies: - dependency-name: curve25519-dalek dependency-type: direct:production ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> (cherry picked from commit 4bd2cf466e) * Updating dual-license language (#110) (cherry picked from commit f79ebf9844) * Bump `curve25519-dalek` to v4.0.0-rc.3 (#113) (cherry picked from commit 209b957ae4) * Bump `curve25519-dalek` to v4 (#116) (cherry picked from commit 0fdfdfdaee) * Fixing clippy IntoIterator warnings (#123) (cherry picked from commit c0162ec8d9) * Bump actions/checkout from 3 to 4 (#120) Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4. - [Release notes](https://github.com/actions/checkout/releases) - [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md) - [Commits](https://github.com/actions/checkout/compare/v3...v4) --- updated-dependencies: - dependency-name: actions/checkout dependency-type: direct:production update-type: version-update:semver-major ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> (cherry picked from commit 8da56845b8) * Updating setup-rust-action (#125) (cherry picked from commit 59e3fedb21) * Test P-521 (#127) (cherry picked from commit 68cc7d3709) * Fix ambiguous lifetime elision (#131) (cherry picked from commit 40769f7eca) * Bump actions/cache from 3 to 4 (#132) Bumps [actions/cache](https://github.com/actions/cache) from 3 to 4. - [Release notes](https://github.com/actions/cache/releases) - [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md) - [Commits](https://github.com/actions/cache/compare/v3...v4) --- updated-dependencies: - dependency-name: actions/cache dependency-type: direct:production update-type: version-update:semver-major ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> (cherry picked from commit c93884aca3) * Fixups + cherry-picking changes from #101 * Fix Clippy warnings * More fixups, tests passing * Ensure CI runs on branch v0.4 --------- Co-authored-by: daxpedda <[email protected]> Co-authored-by: Kevin Lewi <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
2024-09-24 01:55:54 -07:00 · 2024-09-23 23:43:55 -07:00
26 changed files with 458 additions and 277 deletions
@@ -1,6 +1,7 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
@@ -3,8 +3,9 @@ on:
  push:
    branches:
      - main
      - v0.4
  pull_request:
-    types: [opened, repoened, synchronize]
+    types: [opened, reopened, synchronize]
 jobs:
  cargo-audit:
@@ -12,7 +13,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Cache cargo-audit
-        uses: actions/cache@v3
+        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/.crates.toml
@@ -24,7 +25,7 @@ jobs:
        run: cargo install cargo-audit
      - name: Checkout sources
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
      - name: Run cargo audit
        run: cargo audit -D warnings
@@ -35,8 +36,7 @@ jobs:
      fail-fast: false
      matrix:
        backend_feature:
-          - --features ristretto255-ciphersuite,ristretto255-u64
+          - --features ristretto255-ciphersuite
          - --features ristretto255-ciphersuite,ristretto255-u32
          -
        frontend_feature:
          -
@@ -44,11 +44,11 @@ jobs:
          - --features serde
        toolchain:
          - stable
-          - 1.57.0
+          - 1.65.0
    name: test
    steps:
      - name: Checkout sources
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
      - name: Install ${{ matrix.toolchain }} toolchain
        uses: actions-rs/toolchain@v1
@@ -75,6 +75,12 @@ jobs:
          command: test
          args: --no-default-features ${{ matrix.frontend_feature }},std ${{ matrix.backend_feature }}
      - name: Run cargo test with all features enabled
        uses: actions-rs/cargo@v1
        with:
          command: test
          args: --all-features
  build-no-std:
    name: Build with no-std on ${{ matrix.target }}
    runs-on: ubuntu-latest
@@ -88,15 +94,14 @@ jobs:
          - thumbv6m-none-eabi
        backend_feature:
          -
-          - --features ristretto255-ciphersuite,ristretto255-u64
+          - --features ristretto255-ciphersuite
          - --features ristretto255-ciphersuite,ristretto255-u32
        frontend_feature:
          -
          - --features danger
          - --features serde
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
-      - uses: hecrj/setup-rust-action@v1
+      - uses: hecrj/setup-rust-action@v2
      - run: rustup target add ${{ matrix.target }}
      - run: cargo build --verbose --target=${{ matrix.target }} --no-default-features ${{ matrix.frontend_feature }} ${{ matrix.backend_feature }}
@@ -106,7 +111,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout sources
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
      - name: Install stable toolchain
        uses: actions-rs/toolchain@v1
@@ -120,7 +125,7 @@ jobs:
        uses: actions-rs/cargo@v1
        with:
          command: clippy
-          args: --all-targets -- -D warnings
+          args: --all-features --all-targets -- -D warnings
      - name: Run cargo doc
        uses: actions-rs/cargo@v1
@@ -136,7 +141,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout sources
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
      - name: Install nightly toolchain
        uses: actions-rs/toolchain@v1
@@ -157,7 +162,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/.crates.toml
@@ -166,10 +171,10 @@ jobs:
          key: taplo
      - name: Install Taplo
-        run: cargo install taplo-cli
+        run: cargo install taplo-cli --locked
      - name: Checkout sources
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
      - name: Run Taplo
        run: taplo fmt --check
@@ -10,9 +10,10 @@ jobs:
    strategy:
      matrix:
        os: [ubuntu-latest]
        rust: [stable]
    steps:
-    - uses: hecrj/setup-rust-action@v1
+    - uses: hecrj/setup-rust-action@v2
      with:
        rust-version: ${{ matrix.rust }}
    - uses: actions/checkout@master
@@ -8,3 +8,7 @@ Cargo.lock
 # These are backup files generated by rustfmt
 **/*.rs.bk
 # Editors
 .idea
 .vscode
@@ -1,5 +1,10 @@
 # Changelog
 ## 0.4.1 (September 24, 2024)
 * Backport all non-protocol-breaking changes from versions 0.5+
  * Fixes Rust 1.81+ compatibility, compatible with 0.4.0 (draft 11), incompatible with 0.5+ (final RFC)
 * Updated dependencies
 ## 0.4.0 (September 15, 2022)
 * Updated to be in sync with draft-irtf-cfrg-voprf-11, with
  the addition of the POPRF mode
@@ -27,4 +27,5 @@ outlined on that page and do not file a public issue.
 ## License
 By contributing to voprf, you agree that your contributions will be
-licensed under the LICENSE file in the root directory of this source tree.
+licensed under both the LICENSE-MIT and LICENSE-APACHE files in the root
 directory of this source tree.
@@ -7,56 +7,63 @@ keywords = ["oprf"]
 license = "MIT"
 name = "voprf"
 readme = "README.md"
-repository = "https://github.com/novifinancial/voprf/"
+repository = "https://github.com/facebook/voprf/"
-rust-version = "1.57"
+rust-version = "1.65"
-version = "0.4.0"
+version = "0.4.1"
 [features]
 alloc = []
 danger = []
-default = ["ristretto255-ciphersuite", "ristretto255-u64", "serde"]
+default = ["ristretto255-ciphersuite", "dep:serde"]
-ristretto255 = ["curve25519-dalek", "generic-array/more_lengths"]
+ristretto255 = ["dep:curve25519-dalek", "generic-array/more_lengths"]
-ristretto255-ciphersuite = ["ristretto255", "sha2"]
+ristretto255-ciphersuite = ["ristretto255", "dep:sha2"]
-ristretto255-fiat-u32 = ["curve25519-dalek/fiat_u32_backend", "ristretto255"]
+serde = ["generic-array/serde", "dep:serde"]
 ristretto255-fiat-u64 = ["curve25519-dalek/fiat_u64_backend", "ristretto255"]
 ristretto255-simd = ["curve25519-dalek/simd_backend", "ristretto255"]
 ristretto255-u32 = ["curve25519-dalek/u32_backend", "ristretto255"]
 ristretto255-u64 = ["curve25519-dalek/u64_backend", "ristretto255"]
 serde = ["generic-array/serde", "serde_"]
 std = ["alloc"]
 [dependencies]
-curve25519-dalek = { version = "=4.0.0-pre.1", default-features = false, optional = true }
+curve25519-dalek = { version = "4", default-features = false, features = [
  "rand_core",
  "zeroize",
 ], optional = true }
 derive-where = { version = "1", features = ["zeroize-on-drop"] }
 digest = "0.10"
 displaydoc = { version = "0.2", default-features = false }
-elliptic-curve = { version = "0.12", features = [
+elliptic-curve = { version = "0.13", features = [
  "hash2curve",
  "sec1",
  "voprf",
 ] }
 generic-array = "0.14"
 rand_core = { version = "0.6", default-features = false }
-serde_ = { version = "1", package = "serde", default-features = false, features = [
+serde = { version = "1", default-features = false, features = [
  "derive",
 ], optional = true }
 sha2 = { version = "0.10", default-features = false, optional = true }
-subtle = { version = "2.3", default-features = false }
+subtle = { version = "2.6", default-features = false }
-zeroize = { version = "1.5", default-features = false }
+zeroize = { version = "1.8", default-features = false }
 [dev-dependencies]
 generic-array = { version = "0.14", features = ["more_lengths"] }
 hex = "0.4"
-json = "0.12"
+p256 = { version = "0.13", default-features = false, features = [
-p256 = { version = "0.11", default-features = false, features = [
+  "hash2curve",
  "voprf",
 ] }
 p384 = { version = "0.13", default-features = false, features = [
  "hash2curve",
  "voprf",
 ] }
 p521 = { version = "0.13.3", default-features = false, features = [
  "hash2curve",
  "voprf",
 ] }
 proptest = "1"
 rand = "0.8"
 regex = "1"
 serde_json = "1"
 sha2 = "0.10"
 [package.metadata.docs.rs]
-features = ["danger", "std"]
+all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 targets = []
@@ -1,12 +0,0 @@
 ## License
 Licensed under either of
 * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
 * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 at your option.
 ### Contribution
 Unless you explicitly state otherwise, any contribution intentionally submitted
 for inclusion in the work by you, as defined in the Apache-2.0 license, shall
 be dual licensed as above, without any additional terms or conditions.
@@ -1,4 +1,4 @@
-# voprf ![Build Status](https://github.com/novifinancial/voprf/workflows/Rust%20CI/badge.svg)
+# voprf ![Build Status](https://github.com/facebook/voprf/workflows/Rust%20CI/badge.svg)
 An implementation of a (verifiable) oblivious pseudorandom function (VOPRF)
 A VOPRF is a verifiable oblivious pseudorandom function, a protocol between a client and a server. The regular (non-verifiable) OPRF is also supported in this implementation.
@@ -16,12 +16,12 @@ Installation
 Add the following line to the dependencies of your `Cargo.toml`:
 ```
-voprf = "0.4"
+voprf = "0.4.1"
 ```
 ### Minimum Supported Rust Version
-Rust **1.57** or higher.
+Rust **1.65** or higher.
 Contributors
 ------------
@@ -32,4 +32,6 @@ To learn more about contributing to this project, [see this document](./CONTRIBU
 License
 -------
-This project is [licensed](./LICENSE) under either Apache 2.0 or MIT, at your option.
+This project is dual-licensed under either the [MIT license](./LICENSE-MIT)
 or the [Apache License, Version 2.0](./LICENSE-APACHE).
 You may select, at your option, one of the above-listed licenses.
@@ -1,14 +1,15 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Defines the CipherSuite trait to specify the underlying primitives for VOPRF
 use digest::core_api::BlockSizeUser;
-use digest::{Digest, OutputSizeUser};
+use digest::{FixedOutput, HashMarker, OutputSizeUser};
 use elliptic_curve::VoprfParameters;
 use generic_array::typenum::{IsLess, IsLessOrEqual, U256};
@@ -22,7 +23,7 @@ where
 {
    /// The ciphersuite identifier as dictated by
    /// <https://datatracker.ietf.org/doc/draft-irtf-cfrg-voprf/>
-    const ID: u16;
+    const ID: &'static str;
    /// A finite cyclic group along with a point representation that allows some
    /// customization on how to hash an input to a curve point. See [`Group`].
@@ -30,17 +31,17 @@ where
    /// The main hash function to use (for HKDF computations and hashing
    /// transcripts).
-    type Hash: BlockSizeUser + Digest;
+    type Hash: BlockSizeUser + Default + FixedOutput + HashMarker;
 }
 impl<T: VoprfParameters> CipherSuite for T
 where
    T: Group,
-    T::Hash: BlockSizeUser + Digest,
+    T::Hash: BlockSizeUser + Default + FixedOutput + HashMarker,
    <T::Hash as OutputSizeUser>::OutputSize:
        IsLess<U256> + IsLessOrEqual<<T::Hash as BlockSizeUser>::BlockSize>,
 {
-    const ID: u16 = T::ID;
+    const ID: &'static str = T::ID;
    type Group = T;
@@ -1,19 +1,21 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Common functionality between multiple OPRF modes.
 use core::convert::TryFrom;
 use core::ops::Add;
 use derive_where::derive_where;
 use digest::core_api::BlockSizeUser;
 use digest::{Digest, Output, OutputSizeUser};
 use generic_array::sequence::Concat;
-use generic_array::typenum::{IsLess, IsLessOrEqual, Unsigned, U11, U2, U256};
+use generic_array::typenum::{IsLess, IsLessOrEqual, Unsigned, U2, U256, U9};
 use generic_array::{ArrayLength, GenericArray};
 use rand_core::{CryptoRng, RngCore};
 use subtle::ConstantTimeEq;
@@ -72,7 +74,7 @@ impl Mode {
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct BlindedElement<CS: CipherSuite>(
    #[cfg_attr(feature = "serde", serde(with = "Element::<CS::Group>"))]
@@ -89,7 +91,7 @@ where
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct EvaluationElement<CS: CipherSuite>(
    #[cfg_attr(feature = "serde", serde(with = "Element::<CS::Group>"))]
@@ -106,7 +108,7 @@ where
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct PreparedEvaluationElement<CS: CipherSuite>(pub(crate) EvaluationElement<CS>)
 where
@@ -120,7 +122,7 @@ where
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct Proof<CS: CipherSuite>
 where
@@ -145,8 +147,8 @@ pub(crate) fn generate_proof<CS: CipherSuite, R: RngCore + CryptoRng>(
    k: <CS::Group as Group>::Scalar,
    a: <CS::Group as Group>::Elem,
    b: <CS::Group as Group>::Elem,
-    cs: impl Iterator<Item = <CS::Group as Group>::Elem> + ExactSizeIterator,
+    cs: impl ExactSizeIterator<Item = <CS::Group as Group>::Elem>,
-    ds: impl Iterator<Item = <CS::Group as Group>::Elem> + ExactSizeIterator,
+    ds: impl ExactSizeIterator<Item = <CS::Group as Group>::Elem>,
    mode: Mode,
 ) -> Result<Proof<CS>>
 where
@@ -194,9 +196,9 @@ where
        &STR_CHALLENGE,
    ];
-    let dst = GenericArray::from(STR_HASH_TO_SCALAR).concat(create_context_string::<CS>(mode));
+    let dst = Dst::new::<CS, _, _>(STR_HASH_TO_SCALAR, mode);
    // This can't fail, the size of the `input` is known.
-    let c_scalar = CS::Group::hash_to_scalar::<CS::Hash>(&h2_input, &dst).unwrap();
+    let c_scalar = CS::Group::hash_to_scalar::<CS::Hash>(&h2_input, &dst.as_dst()).unwrap();
    let s_scalar = r - &(c_scalar * &k);
    Ok(Proof { c_scalar, s_scalar })
@@ -207,8 +209,8 @@ where
 pub(crate) fn verify_proof<CS: CipherSuite>(
    a: <CS::Group as Group>::Elem,
    b: <CS::Group as Group>::Elem,
-    cs: impl Iterator<Item = <CS::Group as Group>::Elem> + ExactSizeIterator,
+    cs: impl ExactSizeIterator<Item = <CS::Group as Group>::Elem>,
-    ds: impl Iterator<Item = <CS::Group as Group>::Elem> + ExactSizeIterator,
+    ds: impl ExactSizeIterator<Item = <CS::Group as Group>::Elem>,
    proof: &Proof<CS>,
    mode: Mode,
 ) -> Result<()>
@@ -254,9 +256,9 @@ where
        &STR_CHALLENGE,
    ];
-    let dst = GenericArray::from(STR_HASH_TO_SCALAR).concat(create_context_string::<CS>(mode));
+    let dst = Dst::new::<CS, _, _>(STR_HASH_TO_SCALAR, mode);
    // This can't fail, the size of the `input` is known.
-    let c = CS::Group::hash_to_scalar::<CS::Hash>(&h2_input, &dst).unwrap();
+    let c = CS::Group::hash_to_scalar::<CS::Hash>(&h2_input, &dst.as_dst()).unwrap();
    match c.ct_eq(&proof.c_scalar).into() {
        true => Ok(()),
@@ -296,16 +298,16 @@ where
    let len = u16::try_from(c_slice.len()).map_err(|_| Error::Batch)?;
    // seedDST = "Seed-" || contextString
-    let seed_dst = GenericArray::from(STR_SEED).concat(create_context_string::<CS>(mode));
+    let seed_dst = Dst::new::<CS, _, _>(STR_SEED, mode);
    // h1Input = I2OSP(len(Bm), 2) || Bm ||
    //           I2OSP(len(seedDST), 2) || seedDST
    // seed = Hash(h1Input)
    let seed = CS::Hash::new()
-        .chain_update(&elem_len)
+        .chain_update(elem_len)
        .chain_update(CS::Group::serialize_elem(b))
-        .chain_update(i2osp_2_array(&seed_dst))
+        .chain_update(seed_dst.i2osp_2())
-        .chain_update(seed_dst)
+        .chain_update_multi(&seed_dst.as_dst())
        .finalize();
    let seed_len = i2osp_2_array(&seed);
@@ -332,9 +334,9 @@ where
            &STR_COMPOSITE,
        ];
-        let dst = GenericArray::from(STR_HASH_TO_SCALAR).concat(create_context_string::<CS>(mode));
+        let dst = Dst::new::<CS, _, _>(STR_HASH_TO_SCALAR, mode);
        // This can't fail, the size of the `input` is known.
-        let di = CS::Group::hash_to_scalar::<CS::Hash>(&h2_input, &dst).unwrap();
+        let di = CS::Group::hash_to_scalar::<CS::Hash>(&h2_input, &dst.as_dst()).unwrap();
        m = c * &di + &m;
        z = match k_option {
            Some(_) => z,
@@ -365,8 +367,7 @@ where
    <CS::Hash as OutputSizeUser>::OutputSize:
        IsLess<U256> + IsLessOrEqual<<CS::Hash as BlockSizeUser>::BlockSize>,
 {
-    let context_string = create_context_string::<CS>(mode);
+    let dst = Dst::new::<CS, _, _>(STR_DERIVE_KEYPAIR, mode);
    let dst = GenericArray::from(STR_DERIVE_KEYPAIR).concat(context_string);
    let info_len = i2osp_2(info.len()).map_err(|_| Error::DeriveKeyPair)?;
@@ -376,7 +377,7 @@ where
        // || contextString)
        let sk_s = CS::Group::hash_to_scalar::<CS::Hash>(
            &[seed, &info_len, info, &counter.to_be_bytes()],
-            &dst,
+            &dst.as_dst(),
        )
        .map_err(|_| Error::DeriveKeyPair)?;
@@ -388,7 +389,12 @@ where
    Err(Error::Protocol)
 }
-/// Can only fail with [`Error::DeriveKeyPair`] and [`Error::Protocol`].
+/// Corresponds to DeriveKeyPair() function from the VOPRF specification.
 ///
 /// # Errors
 /// - [`Error::DeriveKeyPair`] if the `input` and `seed` together are longer
 ///   then `u16::MAX - 3`.
 /// - [`Error::Protocol`] if the protocol fails and can't be completed.
 #[cfg(feature = "danger")]
 pub fn derive_key<CS: CipherSuite>(
    seed: &[u8],
@@ -450,8 +456,8 @@ where
    <CS::Hash as OutputSizeUser>::OutputSize:
        IsLess<U256> + IsLessOrEqual<<CS::Hash as BlockSizeUser>::BlockSize>,
 {
-    let dst = GenericArray::from(STR_HASH_TO_GROUP).concat(create_context_string::<CS>(mode));
+    let dst = Dst::new::<CS, _, _>(STR_HASH_TO_GROUP, mode);
-    CS::Group::hash_to_curve::<CS::Hash>(&[input], &dst).map_err(|_| Error::Input)
+    CS::Group::hash_to_curve::<CS::Hash>(&[input], &dst.as_dst()).map_err(|_| Error::Input)
 }
 /// Internal function that finalizes the hash input for OPRF, VOPRF & POPRF.
@@ -492,16 +498,70 @@ where
        .finalize())
 }
-/// Generates the contextString parameter as defined in
+pub(crate) struct Dst<L: ArrayLength<u8>> {
-/// <https://datatracker.ietf.org/doc/draft-irtf-cfrg-voprf/>
+    dst_1: GenericArray<u8, L>,
-pub(crate) fn create_context_string<CS: CipherSuite>(mode: Mode) -> GenericArray<u8, U11>
+    dst_2: [u8; 2],
 }
 impl<L: ArrayLength<u8>> Dst<L> {
    pub(crate) fn new<CS: CipherSuite, T, TL>(par_1: T, mode: Mode) -> Self
    where
        T: Into<GenericArray<u8, TL>>,
        TL: ArrayLength<u8> + Add<U9, Output = L>,
        <CS::Hash as OutputSizeUser>::OutputSize:
            IsLess<U256> + IsLessOrEqual<<CS::Hash as BlockSizeUser>::BlockSize>,
    {
        let par_1 = par_1.into();
        // Generates the contextString parameter as defined in
        // <https://datatracker.ietf.org/doc/draft-irtf-cfrg-voprf/>
        let par_2 = GenericArray::from(STR_VOPRF).concat([mode.to_u8()].into());
        // See <https://www.ietf.org/archive/id/draft-irtf-cfrg-voprf-11.html#section-4.1>
        let cs_id_u16: u16 = match CS::ID {
            "ristretto255-SHA512" => 0x0001,
            "decaf448-SHAKE256" => 0x0002,
            "P256-SHA256" => 0x0003,
            "P384-SHA384" => 0x0004,
            "P521-SHA512" => 0x0005,
            _ => panic!("Incompatible ciphersuite: {}", CS::ID),
        };
        let dst_1 = par_1.concat(par_2);
        let dst_2 = cs_id_u16.to_be_bytes();
        assert!(
            L::USIZE + 2 <= u16::MAX.into(),
            "constructed DST longer then {}",
            u16::MAX
        );
        Self { dst_1, dst_2 }
    }
    pub(crate) fn as_dst(&self) -> [&[u8]; 2] {
        [&self.dst_1, &self.dst_2]
    }
    pub(crate) fn i2osp_2(&self) -> [u8; 2] {
        u16::try_from(L::USIZE + 2).unwrap().to_be_bytes()
    }
 }
 trait DigestExt {
    fn chain_update_multi(self, data: &[&[u8]]) -> Self;
 }
 impl<T> DigestExt for T
 where
-    <CS::Hash as OutputSizeUser>::OutputSize:
+    T: Digest,
        IsLess<U256> + IsLessOrEqual<<CS::Hash as BlockSizeUser>::BlockSize>,
 {
-    GenericArray::from(STR_VOPRF)
+    fn chain_update_multi(mut self, datas: &[&[u8]]) -> Self {
-        .concat([mode.to_u8()].into())
+        for data in datas {
-        .concat(CS::ID.to_be_bytes().into())
+            self.update(data)
        }
        self
    }
 }
 ///////////////////////
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Errors which are produced during an execution of the protocol
@@ -1,17 +1,18 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 use digest::core_api::BlockSizeUser;
-use digest::Digest;
+use digest::{FixedOutput, HashMarker};
 use elliptic_curve::group::cofactor::CofactorGroup;
 use elliptic_curve::hash2curve::{ExpandMsgXmd, FromOkm, GroupDigest};
 use elliptic_curve::sec1::{FromEncodedPoint, ModulusSize, ToEncodedPoint};
 use elliptic_curve::{
-    AffinePoint, Field, FieldSize, Group as _, ProjectivePoint, PublicKey, Scalar, SecretKey,
+    AffinePoint, Field, FieldBytesSize, Group as _, ProjectivePoint, PublicKey, Scalar, SecretKey,
 };
 use generic_array::typenum::{IsLess, IsLessOrEqual, U256};
 use generic_array::GenericArray;
@@ -24,32 +25,32 @@ impl<C> Group for C
 where
    C: GroupDigest,
    ProjectivePoint<Self>: CofactorGroup + ToEncodedPoint<Self>,
-    FieldSize<Self>: ModulusSize,
+    FieldBytesSize<Self>: ModulusSize,
    AffinePoint<Self>: FromEncodedPoint<Self> + ToEncodedPoint<Self>,
    Scalar<Self>: FromOkm,
 {
    type Elem = ProjectivePoint<Self>;
-    type ElemLen = <FieldSize<Self> as ModulusSize>::CompressedPointSize;
+    type ElemLen = <FieldBytesSize<Self> as ModulusSize>::CompressedPointSize;
    type Scalar = Scalar<Self>;
-    type ScalarLen = FieldSize<Self>;
+    type ScalarLen = FieldBytesSize<Self>;
    // Implements the `hash_to_curve()` function from
    // https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-hash-to-curve-11#section-3
-    fn hash_to_curve<H>(input: &[&[u8]], dst: &[u8]) -> Result<Self::Elem, InternalError>
+    fn hash_to_curve<H>(input: &[&[u8]], dst: &[&[u8]]) -> Result<Self::Elem, InternalError>
    where
-        H: Digest + BlockSizeUser,
+        H: BlockSizeUser + Default + FixedOutput + HashMarker,
        H::OutputSize: IsLess<U256> + IsLessOrEqual<H::BlockSize>,
    {
        Self::hash_from_bytes::<ExpandMsgXmd<H>>(input, dst).map_err(|_| InternalError::Input)
    }
    // Implements the `HashToScalar()` function
-    fn hash_to_scalar<H>(input: &[&[u8]], dst: &[u8]) -> Result<Self::Scalar, InternalError>
+    fn hash_to_scalar<H>(input: &[&[u8]], dst: &[&[u8]]) -> Result<Self::Scalar, InternalError>
    where
-        H: Digest + BlockSizeUser,
+        H: BlockSizeUser + Default + FixedOutput + HashMarker,
        H::OutputSize: IsLess<U256> + IsLessOrEqual<H::BlockSize>,
    {
        <Self as GroupDigest>::hash_to_scalar::<ExpandMsgXmd<H>>(input, dst)
@@ -92,7 +93,7 @@ where
    #[cfg(test)]
    fn zero_scalar() -> Self::Scalar {
-        Scalar::<Self>::zero()
+        Scalar::<Self>::ZERO
    }
    fn serialize_scalar(scalar: Self::Scalar) -> GenericArray<u8, Self::ScalarLen> {
@@ -100,7 +101,7 @@ where
    }
    fn deserialize_scalar(scalar_bits: &[u8]) -> Result<Self::Scalar> {
-        SecretKey::<Self>::from_be_bytes(scalar_bits)
+        SecretKey::<Self>::from_slice(scalar_bits)
            .map(|secret_key| *secret_key.to_nonzero_scalar())
            .map_err(|_| Error::Deserialization)
    }
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Defines the Group trait to specify the underlying prime order group
@@ -14,7 +15,7 @@ mod ristretto;
 use core::ops::{Add, Mul, Sub};
 use digest::core_api::BlockSizeUser;
-use digest::Digest;
+use digest::{FixedOutput, HashMarker};
 use generic_array::typenum::{IsLess, IsLessOrEqual, U256};
 use generic_array::{ArrayLength, GenericArray};
 use rand_core::{CryptoRng, RngCore};
@@ -54,9 +55,9 @@ pub trait Group {
    /// # Errors
    /// [`Error::Input`](crate::Error::Input) if the `input` is empty or longer
    /// then [`u16::MAX`].
-    fn hash_to_curve<H>(input: &[&[u8]], dst: &[u8]) -> Result<Self::Elem, InternalError>
+    fn hash_to_curve<H>(input: &[&[u8]], dst: &[&[u8]]) -> Result<Self::Elem, InternalError>
    where
-        H: Digest + BlockSizeUser,
+        H: BlockSizeUser + Default + FixedOutput + HashMarker,
        H::OutputSize: IsLess<U256> + IsLessOrEqual<H::BlockSize>;
    /// Hashes a slice of pseudo-random bytes to a scalar
@@ -64,9 +65,9 @@ pub trait Group {
    /// # Errors
    /// [`Error::Input`](crate::Error::Input) if the `input` is empty or longer
    /// then [`u16::MAX`].
-    fn hash_to_scalar<H>(input: &[&[u8]], dst: &[u8]) -> Result<Self::Scalar, InternalError>
+    fn hash_to_scalar<H>(input: &[&[u8]], dst: &[&[u8]]) -> Result<Self::Scalar, InternalError>
    where
-        H: Digest + BlockSizeUser,
+        H: BlockSizeUser + Default + FixedOutput + HashMarker,
        H::OutputSize: IsLess<U256> + IsLessOrEqual<H::BlockSize>;
    /// Get the base point for the group
@@ -1,16 +1,17 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 use curve25519_dalek::constants::RISTRETTO_BASEPOINT_POINT;
 use curve25519_dalek::ristretto::{CompressedRistretto, RistrettoPoint};
 use curve25519_dalek::scalar::Scalar;
 use curve25519_dalek::traits::Identity;
 use digest::core_api::BlockSizeUser;
-use digest::Digest;
+use digest::{FixedOutput, HashMarker};
 use elliptic_curve::hash2curve::{ExpandMsg, ExpandMsgXmd, Expander};
 use generic_array::typenum::{IsLess, IsLessOrEqual, U256, U32, U64};
 use generic_array::GenericArray;
@@ -22,21 +23,17 @@ use crate::{Error, InternalError, Result};
 /// [`Group`] implementation for Ristretto255.
 #[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
 // `cfg` here is only needed because of a bug in Rust's crate feature documentation. See: https://github.com/rust-lang/rust/issues/83428
 #[cfg(feature = "ristretto255")]
 pub struct Ristretto255;
 #[cfg(feature = "ristretto255-ciphersuite")]
 impl crate::CipherSuite for Ristretto255 {
-    const ID: u16 = 0x0001;
+    const ID: &'static str = "ristretto255-SHA512";
    type Group = Ristretto255;
    type Hash = sha2::Sha512;
 }
 // `cfg` here is only needed because of a bug in Rust's crate feature documentation. See: https://github.com/rust-lang/rust/issues/83428
 #[cfg(feature = "ristretto255")]
 impl Group for Ristretto255 {
    type Elem = RistrettoPoint;
@@ -48,9 +45,9 @@ impl Group for Ristretto255 {
    // Implements the `hash_to_ristretto255()` function from
    // https://www.ietf.org/archive/id/draft-irtf-cfrg-hash-to-curve-10.txt
-    fn hash_to_curve<H>(input: &[&[u8]], dst: &[u8]) -> Result<Self::Elem, InternalError>
+    fn hash_to_curve<H>(input: &[&[u8]], dst: &[&[u8]]) -> Result<Self::Elem, InternalError>
    where
-        H: Digest + BlockSizeUser,
+        H: BlockSizeUser + Default + FixedOutput + HashMarker,
        H::OutputSize: IsLess<U256> + IsLessOrEqual<H::BlockSize>,
    {
        let mut uniform_bytes = GenericArray::<_, U64>::default();
@@ -63,9 +60,9 @@ impl Group for Ristretto255 {
    // Implements the `HashToScalar()` function from
    // https://www.ietf.org/archive/id/draft-irtf-cfrg-voprf-07.html#section-4.1
-    fn hash_to_scalar<H>(input: &[&[u8]], dst: &[u8]) -> Result<Self::Scalar, InternalError>
+    fn hash_to_scalar<H>(input: &[&[u8]], dst: &[&[u8]]) -> Result<Self::Scalar, InternalError>
    where
-        H: Digest + BlockSizeUser,
+        H: BlockSizeUser + Default + FixedOutput + HashMarker,
        H::OutputSize: IsLess<U256> + IsLessOrEqual<H::BlockSize>,
    {
        let mut uniform_bytes = GenericArray::<_, U64>::default();
@@ -90,11 +87,8 @@ impl Group for Ristretto255 {
    }
    fn deserialize_elem(element_bits: &[u8]) -> Result<Self::Elem> {
        if element_bits.len() != 32 {
            return Err(Error::Deserialization);
        }
        CompressedRistretto::from_slice(element_bits)
            .map_err(|_| Error::Deserialization)?
            .decompress()
            .filter(|point| point != &RistrettoPoint::identity())
            .ok_or(Error::Deserialization)
@@ -104,7 +98,7 @@ impl Group for Ristretto255 {
        loop {
            let scalar = Scalar::random(rng);
-            if scalar != Scalar::zero() {
+            if scalar != Scalar::ZERO {
                break scalar;
            }
        }
@@ -115,12 +109,12 @@ impl Group for Ristretto255 {
    }
    fn is_zero_scalar(scalar: Self::Scalar) -> subtle::Choice {
-        scalar.ct_eq(&Scalar::zero())
+        scalar.ct_eq(&Scalar::ZERO)
    }
    #[cfg(test)]
    fn zero_scalar() -> Self::Scalar {
-        Scalar::zero()
+        Scalar::ZERO
    }
    fn serialize_scalar(scalar: Self::Scalar) -> GenericArray<u8, Self::ScalarLen> {
@@ -131,8 +125,8 @@ impl Group for Ristretto255 {
        scalar_bits
            .try_into()
            .ok()
-            .and_then(Scalar::from_canonical_bytes)
+            .and_then(|bytes| Scalar::from_canonical_bytes(bytes).into())
-            .filter(|scalar| scalar != &Scalar::zero())
+            .filter(|scalar| scalar != &Scalar::ZERO)
            .ok_or(Error::Deserialization)
    }
 }
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Includes a series of tests for the group implementations
@@ -15,6 +16,8 @@ use crate::{Error, Group, Result};
 #[test]
 fn test_group_properties() -> Result<()> {
    use p256::NistP256;
    use p384::NistP384;
    use p521::NistP521;
    #[cfg(feature = "ristretto255")]
    {
@@ -27,6 +30,12 @@ fn test_group_properties() -> Result<()> {
    test_identity_element_error::<NistP256>()?;
    test_zero_scalar_error::<NistP256>()?;
    test_identity_element_error::<NistP384>()?;
    test_zero_scalar_error::<NistP384>()?;
    test_identity_element_error::<NistP521>()?;
    test_zero_scalar_error::<NistP521>()?;
    Ok(())
 }
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! An implementation of a verifiable oblivious pseudorandom function (VOPRF)
 //!
@@ -532,24 +533,15 @@
 //!   a [`CipherSuite`].
 //!
 //! - The `ristretto255` feature enables using [`Ristretto255`] as the
-//!   underlying group for the [Group] choice. A backend feature, which are
+//!   underlying group for the [Group] choice. To select a specific backend see
-//!   re-exported from [curve25519-dalek] and allow for selecting the
+//!   the [curve25519-dalek] documentation.
 //!   corresponding backend for the curve arithmetic used, has to be selected,
 //!   otherwise compilation will fail. The `ristretto255-u64` feature is
 //!   included as the default. Other features are mapped as `ristretto255-u32`,
 //!   `ristretto255-fiat-u64` and `ristretto255-fiat-u32`. Any `ristretto255-*`
 //!   backend feature will enable the `ristretto255` feature.
 //!
 //! - The `ristretto255-simd` feature is re-exported from [curve25519-dalek] and
 //!   enables parallel formulas, using either AVX2 or AVX512-IFMA. This will
 //!   automatically enable the `ristretto255-u64` feature and requires Rust
 //!   nightly.
 //!
 //! [curve25519-dalek]:
-//!     (https://doc.dalek.rs/curve25519_dalek/index.html#backends-and-features)
+//!     (https://docs.rs/curve25519-dalek/4.0.0-pre.5/curve25519_dalek/index.html#backends)
 #![cfg_attr(not(test), deny(unsafe_code))]
 #![no_std]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![cfg_attr(not(test), deny(unsafe_code))]
 #![warn(
    clippy::cargo,
    clippy::missing_errors_doc,
@@ -564,9 +556,6 @@ extern crate alloc;
 #[cfg(feature = "std")]
 extern crate std;
 #[cfg(feature = "serde")]
 extern crate serde_ as serde;
 mod ciphersuite;
 mod common;
 mod error;
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Contains the main OPRF API
@@ -41,7 +42,7 @@ use crate::{CipherSuite, Error, Group, Result};
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct OprfClient<CS: CipherSuite>
 where
@@ -59,7 +60,7 @@ where
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct OprfServer<CS: CipherSuite>
 where
@@ -277,7 +278,7 @@ where
            .chain_update(input.as_ref())
            .chain_update(elem_len)
            .chain_update(CS::Group::serialize_elem(unblinded_element))
-            .chain_update(&STR_FINALIZE)
+            .chain_update(STR_FINALIZE)
            .finalize())
    })
 }
@@ -291,11 +292,10 @@ where
 mod tests {
    use core::ptr;
    use generic_array::sequence::Concat;
    use rand::rngs::OsRng;
    use super::*;
-    use crate::common::{create_context_string, STR_HASH_TO_GROUP};
+    use crate::common::{Dst, STR_HASH_TO_GROUP};
    use crate::Group;
    fn prf<CS: CipherSuite>(
@@ -308,8 +308,8 @@ mod tests {
        <CS::Hash as OutputSizeUser>::OutputSize:
            IsLess<U256> + IsLessOrEqual<<CS::Hash as BlockSizeUser>::BlockSize>,
    {
-        let dst = GenericArray::from(STR_HASH_TO_GROUP).concat(create_context_string::<CS>(mode));
+        let dst = Dst::new::<CS, _, _>(STR_HASH_TO_GROUP, mode);
-        let point = CS::Group::hash_to_curve::<CS::Hash>(&[input], &dst).unwrap();
+        let point = CS::Group::hash_to_curve::<CS::Hash>(&[input], &dst.as_dst()).unwrap();
        let res = point * &key;
@@ -348,9 +348,8 @@ mod tests {
            .finalize(&input, &EvaluationElement(client_blind_result.message.0))
            .unwrap();
-        let dst =
+        let dst = Dst::new::<CS, _, _>(STR_HASH_TO_GROUP, Mode::Oprf);
-            GenericArray::from(STR_HASH_TO_GROUP).concat(create_context_string::<CS>(Mode::Oprf));
+        let point = CS::Group::hash_to_curve::<CS::Hash>(&[&input], &dst.as_dst()).unwrap();
        let point = CS::Group::hash_to_curve::<CS::Hash>(&[&input], &dst).unwrap();
        let res2 = finalize_after_unblind::<CS, _, _>(iter::once((input.as_ref(), point)), &[])
            .next()
            .unwrap()
@@ -427,6 +426,8 @@ mod tests {
    #[test]
    fn test_functionality() -> Result<()> {
        use p256::NistP256;
        use p384::NistP384;
        use p521::NistP521;
        #[cfg(feature = "ristretto255")]
        {
@@ -447,6 +448,20 @@ mod tests {
        zeroize_oprf_client::<NistP256>();
        zeroize_oprf_server::<NistP256>();
        base_retrieval::<NistP384>();
        base_inversion_unsalted::<NistP384>();
        server_evaluate::<NistP384>();
        zeroize_oprf_client::<NistP384>();
        zeroize_oprf_server::<NistP384>();
        base_retrieval::<NistP521>();
        base_inversion_unsalted::<NistP521>();
        server_evaluate::<NistP521>();
        zeroize_oprf_client::<NistP521>();
        zeroize_oprf_server::<NistP521>();
        Ok(())
    }
 }
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Contains the main POPRF API
@@ -14,16 +15,14 @@ use core::iter::{self, Map, Repeat, Zip};
 use derive_where::derive_where;
 use digest::core_api::BlockSizeUser;
 use digest::{Digest, Output, OutputSizeUser};
 use generic_array::sequence::Concat;
 use generic_array::typenum::{IsLess, IsLessOrEqual, Unsigned, U256};
 use generic_array::GenericArray;
 use rand_core::{CryptoRng, RngCore};
 use crate::common::{
-    create_context_string, derive_keypair, deterministic_blind_unchecked, generate_proof,
+    derive_keypair, deterministic_blind_unchecked, generate_proof, hash_to_group, i2osp_2,
-    hash_to_group, i2osp_2, server_evaluate_hash_input, verify_proof, BlindedElement,
+    server_evaluate_hash_input, verify_proof, BlindedElement, Dst, EvaluationElement, Mode,
-    EvaluationElement, Mode, PreparedEvaluationElement, Proof, STR_FINALIZE, STR_HASH_TO_SCALAR,
+    PreparedEvaluationElement, Proof, STR_FINALIZE, STR_HASH_TO_SCALAR, STR_INFO,
    STR_INFO,
 };
 #[cfg(feature = "serde")]
 use crate::serialization::serde::{Element, Scalar};
@@ -41,7 +40,7 @@ use crate::{CipherSuite, Error, Group, Result};
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct PoprfClient<CS: CipherSuite>
 where
@@ -61,7 +60,7 @@ where
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct PoprfServer<CS: CipherSuite>
 where
@@ -541,7 +540,7 @@ pub type PoprfServerBatchEvaluatePreparedEvaluationElements<CS, I> = Map<
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct PoprfPreparedTweak<CS: CipherSuite>(
    #[cfg_attr(feature = "serde", serde(with = "Scalar::<CS::Group>"))]
@@ -616,10 +615,9 @@ where
    let info_len = i2osp_2(info.len()).map_err(|_| Error::Info)?;
    let framed_info = [STR_INFO.as_slice(), &info_len, info];
-    let dst =
+    let dst = Dst::new::<CS, _, _>(STR_HASH_TO_SCALAR, Mode::Poprf);
        GenericArray::from(STR_HASH_TO_SCALAR).concat(create_context_string::<CS>(Mode::Poprf));
    // This can't fail, the size of the `input` is known.
-    let m = CS::Group::hash_to_scalar::<CS::Hash>(&framed_info, &dst).unwrap();
+    let m = CS::Group::hash_to_scalar::<CS::Hash>(&framed_info, &dst.as_dst()).unwrap();
    let t = CS::Group::base_elem() * &m;
    let tweaked_key = t + &pk;
@@ -654,10 +652,9 @@ where
    let info_len = i2osp_2(info.len()).map_err(|_| Error::Info)?;
    let framed_info = [STR_INFO.as_slice(), &info_len, info];
-    let dst =
+    let dst = Dst::new::<CS, _, _>(STR_HASH_TO_SCALAR, Mode::Poprf);
        GenericArray::from(STR_HASH_TO_SCALAR).concat(create_context_string::<CS>(Mode::Poprf));
    // This can't fail, the size of the `input` is known.
-    let m = CS::Group::hash_to_scalar::<CS::Hash>(&framed_info, &dst).unwrap();
+    let m = CS::Group::hash_to_scalar::<CS::Hash>(&framed_info, &dst.as_dst()).unwrap();
    let t = sk + &m;
@@ -723,7 +720,7 @@ where
    )?;
    Ok(blinds
-        .zip(messages.into_iter())
+        .zip(messages)
        .map(|(blind, x)| x.0 * &CS::Group::invert_scalar(blind)))
 }
@@ -810,8 +807,8 @@ mod tests {
    {
        let t = compute_tweak::<CS>(key, Some(info)).unwrap();
-        let dst = GenericArray::from(STR_HASH_TO_GROUP).concat(create_context_string::<CS>(mode));
+        let dst = Dst::new::<CS, _, _>(STR_HASH_TO_GROUP, mode);
-        let point = CS::Group::hash_to_curve::<CS::Hash>(&[input], &dst).unwrap();
+        let point = CS::Group::hash_to_curve::<CS::Hash>(&[input], &dst.as_dst()).unwrap();
        // evaluatedElement = G.ScalarInverse(t) * blindedElement
        let res = point * &CS::Group::invert_scalar(t);
@@ -864,10 +861,9 @@ mod tests {
            .blind_evaluate(&mut rng, &client_blind_result.message, Some(info))
            .unwrap();
        let wrong_pk = {
-            let dst = GenericArray::from(STR_HASH_TO_GROUP)
+            let dst = Dst::new::<CS, _, _>(STR_HASH_TO_GROUP, Mode::Oprf);
                .concat(create_context_string::<CS>(Mode::Oprf));
            // Choose a group element that is unlikely to be the right public key
-            CS::Group::hash_to_curve::<CS::Hash>(&[b"msg"], &dst).unwrap()
+            CS::Group::hash_to_curve::<CS::Hash>(&[b"msg"], &dst.as_dst()).unwrap()
        };
        let client_finalize_result = client_blind_result.state.finalize(
            input,
@@ -970,6 +966,8 @@ mod tests {
    #[test]
    fn test_functionality() -> Result<()> {
        use p256::NistP256;
        use p384::NistP384;
        use p521::NistP521;
        #[cfg(feature = "ristretto255")]
        {
@@ -990,6 +988,20 @@ mod tests {
        zeroize_verifiable_client::<NistP256>();
        zeroize_verifiable_server::<NistP256>();
        verifiable_retrieval::<NistP384>();
        verifiable_bad_public_key::<NistP384>();
        verifiable_server_evaluate::<NistP384>();
        zeroize_verifiable_client::<NistP384>();
        zeroize_verifiable_server::<NistP384>();
        verifiable_retrieval::<NistP521>();
        verifiable_bad_public_key::<NistP521>();
        verifiable_server_evaluate::<NistP521>();
        zeroize_verifiable_client::<NistP521>();
        zeroize_verifiable_server::<NistP521>();
        Ok(())
    }
 }
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Handles the serialization of each of the components used in the VOPRF
 //! protocol
@@ -306,11 +307,11 @@ fn deserialize_scalar<G: Group>(input: &mut &[u8]) -> Result<G::Scalar> {
 }
 trait SliceExt {
-    fn take_ext(self: &mut &Self, take: usize) -> Option<&Self>;
+    fn take_ext<'a>(self: &mut &'a Self, take: usize) -> Option<&'a Self>;
 }
 impl<T> SliceExt for [T] {
-    fn take_ext(self: &mut &Self, take: usize) -> Option<&Self> {
+    fn take_ext<'a>(self: &mut &'a Self, take: usize) -> Option<&'a Self> {
        if take > self.len() {
            return None;
        }
@@ -389,6 +390,8 @@ mod test {
            }
            let _ = $item::<p256::NistP256>::deserialize(&$bytes[..]);
            let _ = $item::<p384::NistP384>::deserialize(&$bytes[..]);
            let _ = $item::<p521::NistP521>::deserialize(&$bytes[..]);
        };
    }
@@ -1,12 +1,13 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! The VOPRF test vectors taken from:
-//! https://github.com/cfrg/draft-irtf-cfrg-voprf/blob/master/draft-irtf-cfrg-voprf.md
+//! https://github.com/cfrg/draft-irtf-cfrg-voprf/blob/dff20b461c0de23fcd521116f3d058cfa5b80b90/draft-irtf-cfrg-voprf.md
 pub(crate) const VECTORS: &str = r#"
 ## OPRF(ristretto255, SHA-512)
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 use alloc::vec::Vec;
 use core::cmp::min;
@@ -50,7 +51,7 @@ impl RngCore for CycleRng {
    #[inline]
    fn fill_bytes(&mut self, dest: &mut [u8]) {
        let len = min(self.v.len(), dest.len());
-        (&mut dest[..len]).copy_from_slice(&self.v[..len]);
+        dest[..len].copy_from_slice(&self.v[..len]);
        rotate_left(&mut self.v, len);
    }
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 mod cfrg_vectors;
 mod mock_rng;
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 use alloc::string::{String, ToString};
 use alloc::vec::Vec;
@@ -96,7 +97,7 @@ fn parse_params(input: &str) -> String {
                    let key = iter.next().unwrap().split_whitespace().next().unwrap();
                    let val = iter.next().unwrap().split_whitespace().next().unwrap();
-                    param = format!("    \"{}\": \"{}", key, val);
+                    param = format!("    \"{key}\": \"{val}");
                } else {
                    let s = line.trim().to_string();
                    if s.contains('~') || s.contains('#') {
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 use alloc::string::String;
 use alloc::vec;
@@ -14,7 +15,7 @@ use digest::core_api::BlockSizeUser;
 use digest::OutputSizeUser;
 use generic_array::typenum::{IsLess, IsLessOrEqual, Sum, U256};
 use generic_array::ArrayLength;
-use json::JsonValue;
+use serde_json::Value;
 use crate::tests::mock_rng::CycleRng;
 use crate::tests::parser::*;
@@ -40,7 +41,7 @@ struct VOPRFTestVectorParameters {
    output: Vec<Vec<u8>>,
 }
-fn populate_test_vectors(values: &JsonValue) -> VOPRFTestVectorParameters {
+fn populate_test_vectors(values: &Value) -> VOPRFTestVectorParameters {
    VOPRFTestVectorParameters {
        seed: decode(values, "Seed"),
        sksm: decode(values, "skSm"),
@@ -57,18 +58,18 @@ fn populate_test_vectors(values: &JsonValue) -> VOPRFTestVectorParameters {
    }
 }
-fn decode(values: &JsonValue, key: &str) -> Vec<u8> {
+fn decode(values: &Value, key: &str) -> Vec<u8> {
    values[key]
        .as_str()
-        .and_then(|s| hex::decode(&s).ok())
+        .and_then(|s| hex::decode(s).ok())
        .unwrap_or_default()
 }
-fn decode_vec(values: &JsonValue, key: &str) -> Vec<Vec<u8>> {
+fn decode_vec(values: &Value, key: &str) -> Vec<Vec<u8>> {
    let s = values[key].as_str().unwrap();
    let res = match s.contains(',') {
-        true => Some(s.split(',').map(|x| hex::decode(&x).unwrap()).collect()),
+        true => Some(s.split(',').map(|x| hex::decode(x).unwrap()).collect()),
-        false => Some(vec![hex::decode(&s).unwrap()]),
+        false => Some(vec![hex::decode(s).unwrap()]),
    };
    res.unwrap()
 }
@@ -76,8 +77,10 @@ fn decode_vec(values: &JsonValue, key: &str) -> Vec<Vec<u8>> {
 macro_rules! json_to_test_vectors {
    ( $v:ident, $cs:expr, $mode:expr ) => {
        $v[$cs][$mode]
-            .members()
+            .as_array()
-            .map(|x| populate_test_vectors(&x))
+            .into_iter()
            .flatten()
            .map(populate_test_vectors)
            .collect::<Vec<VOPRFTestVectorParameters>>()
    };
 }
@@ -85,8 +88,10 @@ macro_rules! json_to_test_vectors {
 #[test]
 fn test_vectors() -> Result<()> {
    use p256::NistP256;
    use p384::NistP384;
    use p521::NistP521;
-    let rfc = json::parse(rfc_to_json(super::cfrg_vectors::VECTORS).as_str())
+    let rfc: Value = serde_json::from_str(rfc_to_json(super::cfrg_vectors::VECTORS).as_str())
        .expect("Could not parse json");
    #[cfg(feature = "ristretto255")]
@@ -157,6 +162,60 @@ fn test_vectors() -> Result<()> {
    test_poprf_finalize::<NistP256>(&p256_poprf_tvs)?;
    test_poprf_evaluate::<NistP256>(&p256_poprf_tvs)?;
    let p384_oprf_tvs =
        json_to_test_vectors!(rfc, String::from("P-384, SHA-384"), String::from("OPRF"));
    assert_ne!(p384_oprf_tvs.len(), 0);
    test_oprf_seed_to_key::<NistP384>(&p384_oprf_tvs)?;
    test_oprf_blind::<NistP384>(&p384_oprf_tvs)?;
    test_oprf_blind_evaluate::<NistP384>(&p384_oprf_tvs)?;
    test_oprf_finalize::<NistP384>(&p384_oprf_tvs)?;
    test_oprf_evaluate::<NistP384>(&p384_oprf_tvs)?;
    let p384_voprf_tvs =
        json_to_test_vectors!(rfc, String::from("P-384, SHA-384"), String::from("VOPRF"));
    assert_ne!(p384_voprf_tvs.len(), 0);
    test_voprf_seed_to_key::<NistP384>(&p384_voprf_tvs)?;
    test_voprf_blind::<NistP384>(&p384_voprf_tvs)?;
    test_voprf_blind_evaluate::<NistP384>(&p384_voprf_tvs)?;
    test_voprf_finalize::<NistP384>(&p384_voprf_tvs)?;
    test_voprf_evaluate::<NistP384>(&p384_voprf_tvs)?;
    let p384_poprf_tvs =
        json_to_test_vectors!(rfc, String::from("P-384, SHA-384"), String::from("POPRF"));
    assert_ne!(p384_poprf_tvs.len(), 0);
    test_poprf_seed_to_key::<NistP384>(&p384_poprf_tvs)?;
    test_poprf_blind::<NistP384>(&p384_poprf_tvs)?;
    test_poprf_blind_evaluate::<NistP384>(&p384_poprf_tvs)?;
    test_poprf_finalize::<NistP384>(&p384_poprf_tvs)?;
    test_poprf_evaluate::<NistP384>(&p384_poprf_tvs)?;
    let p521_oprf_tvs =
        json_to_test_vectors!(rfc, String::from("P-521, SHA-512"), String::from("OPRF"));
    assert_ne!(p521_oprf_tvs.len(), 0);
    test_oprf_seed_to_key::<NistP521>(&p521_oprf_tvs)?;
    test_oprf_blind::<NistP521>(&p521_oprf_tvs)?;
    test_oprf_blind_evaluate::<NistP521>(&p521_oprf_tvs)?;
    test_oprf_finalize::<NistP521>(&p521_oprf_tvs)?;
    test_oprf_evaluate::<NistP521>(&p521_oprf_tvs)?;
    let p521_voprf_tvs =
        json_to_test_vectors!(rfc, String::from("P-521, SHA-512"), String::from("VOPRF"));
    assert_ne!(p521_voprf_tvs.len(), 0);
    test_voprf_seed_to_key::<NistP521>(&p521_voprf_tvs)?;
    test_voprf_blind::<NistP521>(&p521_voprf_tvs)?;
    test_voprf_blind_evaluate::<NistP521>(&p521_voprf_tvs)?;
    test_voprf_finalize::<NistP521>(&p521_voprf_tvs)?;
    test_voprf_evaluate::<NistP521>(&p521_voprf_tvs)?;
    let p521_poprf_tvs =
        json_to_test_vectors!(rfc, String::from("P-521, SHA-512"), String::from("POPRF"));
    assert_ne!(p521_poprf_tvs.len(), 0);
    test_poprf_seed_to_key::<NistP521>(&p521_poprf_tvs)?;
    test_poprf_blind::<NistP521>(&p521_poprf_tvs)?;
    test_poprf_blind_evaluate::<NistP521>(&p521_poprf_tvs)?;
    test_poprf_finalize::<NistP521>(&p521_poprf_tvs)?;
    test_poprf_evaluate::<NistP521>(&p521_poprf_tvs)?;
    Ok(())
 }
@@ -1,9 +1,10 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
+// Copyright (c) Meta Platforms, Inc. and affiliates.
 //
-// This source code is licensed under both the MIT license found in the
+// This source code is dual-licensed under either the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
+// LICENSE-MIT file in the root directory of this source tree or the Apache
 // License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
+// of this source tree. You may select, at your option, one of the above-listed
 // licenses.
 //! Contains the main VOPRF API
@@ -39,7 +40,7 @@ use crate::{CipherSuite, Error, Group, Result};
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct VoprfClient<CS: CipherSuite>
 where
@@ -59,7 +60,7 @@ where
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde", bound = "")
+    serde(bound = "")
 )]
 pub struct VoprfServer<CS: CipherSuite>
 where
@@ -160,7 +161,7 @@ where
    ///
    /// The resulting messages can each fail individually with [`Error::Input`]
    /// if the `input` is empty or longer then [`u16::MAX`].
-    pub fn batch_finalize<'a, I: 'a, II, IC, IM>(
+    pub fn batch_finalize<'a, I, II, IC, IM>(
        inputs: &'a II,
        clients: &'a IC,
        messages: &'a IM,
@@ -169,7 +170,7 @@ where
    ) -> Result<VoprfClientBatchFinalizeResult<'a, CS, I, II, IC, IM>>
    where
        CS: 'a,
-        I: AsRef<[u8]>,
+        I: 'a + AsRef<[u8]>,
        &'a II: 'a + IntoIterator<Item = I>,
        <&'a II as IntoIterator>::IntoIter: ExactSizeIterator,
        &'a IC: 'a + IntoIterator<Item = &'a VoprfClient<CS>>,
@@ -536,7 +537,7 @@ where
    )?;
    Ok(blinds
-        .zip(messages.into_iter())
+        .zip(messages)
        .map(|(blind, x)| x.0 * &CS::Group::invert_scalar(blind)))
 }
@@ -587,13 +588,12 @@ mod tests {
    use ::alloc::vec;
    use ::alloc::vec::Vec;
    use generic_array::sequence::Concat;
    use generic_array::typenum::Sum;
    use generic_array::ArrayLength;
    use rand::rngs::OsRng;
    use super::*;
-    use crate::common::{create_context_string, STR_HASH_TO_GROUP};
+    use crate::common::{Dst, STR_HASH_TO_GROUP};
    use crate::Group;
    fn prf<CS: CipherSuite>(
@@ -605,8 +605,8 @@ mod tests {
        <CS::Hash as OutputSizeUser>::OutputSize:
            IsLess<U256> + IsLessOrEqual<<CS::Hash as BlockSizeUser>::BlockSize>,
    {
-        let dst = GenericArray::from(STR_HASH_TO_GROUP).concat(create_context_string::<CS>(mode));
+        let dst = Dst::new::<CS, _, _>(STR_HASH_TO_GROUP, mode);
-        let point = CS::Group::hash_to_curve::<CS::Hash>(&[input], &dst).unwrap();
+        let point = CS::Group::hash_to_curve::<CS::Hash>(&[input], &dst.as_dst()).unwrap();
        let res = point * &key;
@@ -718,10 +718,9 @@ mod tests {
            .unwrap();
        let messages: Vec<_> = messages.collect();
        let wrong_pk = {
-            let dst = GenericArray::from(STR_HASH_TO_GROUP)
+            let dst = Dst::new::<CS, _, _>(STR_HASH_TO_GROUP, Mode::Oprf);
                .concat(create_context_string::<CS>(Mode::Oprf));
            // Choose a group element that is unlikely to be the right public key
-            CS::Group::hash_to_curve::<CS::Hash>(&[b"msg"], &dst).unwrap()
+            CS::Group::hash_to_curve::<CS::Hash>(&[b"msg"], &dst.as_dst()).unwrap()
        };
        let client_finalize_result =
            VoprfClient::batch_finalize(&inputs, &client_states, &messages, &proof, wrong_pk);
@@ -739,10 +738,9 @@ mod tests {
        let server = VoprfServer::<CS>::new(&mut rng).unwrap();
        let server_result = server.blind_evaluate(&mut rng, &client_blind_result.message);
        let wrong_pk = {
-            let dst = GenericArray::from(STR_HASH_TO_GROUP)
+            let dst = Dst::new::<CS, _, _>(STR_HASH_TO_GROUP, Mode::Oprf);
                .concat(create_context_string::<CS>(Mode::Oprf));
            // Choose a group element that is unlikely to be the right public key
-            CS::Group::hash_to_curve::<CS::Hash>(&[b"msg"], &dst).unwrap()
+            CS::Group::hash_to_curve::<CS::Hash>(&[b"msg"], &dst.as_dst()).unwrap()
        };
        let client_finalize_result = client_blind_result.state.finalize(
            input,
@@ -837,6 +835,8 @@ mod tests {
    #[test]
    fn test_functionality() -> Result<()> {
        use p256::NistP256;
        use p384::NistP384;
        use p521::NistP521;
        #[cfg(feature = "ristretto255")]
        {
@@ -861,6 +861,24 @@ mod tests {
        zeroize_voprf_client::<NistP256>();
        zeroize_voprf_server::<NistP256>();
        verifiable_retrieval::<NistP384>();
        verifiable_batch_retrieval::<NistP384>();
        verifiable_bad_public_key::<NistP384>();
        verifiable_batch_bad_public_key::<NistP384>();
        verifiable_server_evaluate::<NistP384>();
        zeroize_voprf_client::<NistP384>();
        zeroize_voprf_server::<NistP384>();
        verifiable_retrieval::<NistP521>();
        verifiable_batch_retrieval::<NistP521>();
        verifiable_bad_public_key::<NistP521>();
        verifiable_batch_bad_public_key::<NistP521>();
        verifiable_server_evaluate::<NistP521>();
        zeroize_voprf_client::<NistP521>();
        zeroize_voprf_server::<NistP521>();
        Ok(())
    }
 }