diff --git a/.github/workflows/bash-f.yml b/.github/workflows/bash-f.yml
new file mode 100644
index 0000000..7614514
--- /dev/null
+++ b/.github/workflows/bash-f.yml
@@ -0,0 +1,92 @@
+name: bash-f
+
+on:
+  pull_request:
+    paths:
+      - "bash-f.yml"
+      - "bash-f/**"
+      - "Cargo.*"
+  push:
+    branches: master
+
+defaults:
+  run:
+    working-directory: bash-f
+
+env:
+  RUSTFLAGS: "-Dwarnings"
+  CARGO_INCREMENTAL: 0
+
+jobs:
+  set-msrv:
+    uses: RustCrypto/actions/.github/workflows/set-msrv.yml@master
+    with:
+      msrv: 1.85.0
+
+  build:
+    needs: set-msrv
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - ${{needs.set-msrv.outputs.msrv}}
+          - stable
+        target:
+          - thumbv7em-none-eabi
+          - wasm32-unknown-unknown
+    steps:
+      - uses: actions/checkout@v4
+      - uses: RustCrypto/actions/cargo-cache@master
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+          targets: ${{ matrix.target }}
+      - run: cargo build --no-default-features --target ${{ matrix.target }}
+
+  minimal-versions:
+    uses: RustCrypto/actions/.github/workflows/minimal-versions.yml@master
+    with:
+      working-directory: ${{ github.workflow }}
+
+  test:
+    needs: set-msrv
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - ${{needs.set-msrv.outputs.msrv}}
+          - stable
+    steps:
+      - uses: actions/checkout@v4
+      - uses: RustCrypto/actions/cargo-cache@master
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+      - run: cargo test --no-default-features
+      - run: cargo test
+      - run: cargo test --all-features
+
+  miri:
+    runs-on: ubuntu-latest
+    env:
+      MIRIFLAGS: "-Zmiri-symbolic-alignment-check -Zmiri-strict-provenance"
+    strategy:
+      matrix:
+        target:
+          - x86_64-unknown-linux-gnu
+          - s390x-unknown-linux-gnu
+    steps:
+      - uses: actions/checkout@v4
+      - uses: RustCrypto/actions/cargo-cache@master
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: nightly
+      - name: Install Miri
+        run: |
+          rustup component add miri
+          cargo miri setup
+      - name: Test with Miri
+        run: |
+          cargo miri test --target ${{ matrix.target }} --no-default-features
+          cargo miri test --target ${{ matrix.target }}
+          cargo miri test --target ${{ matrix.target }} --all-features
diff --git a/Cargo.lock b/Cargo.lock
index 3d67e6f..1b499e2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9,6 +9,10 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "bash-f"
+version = "0.1.0-rc.0"
+
 [[package]]
 name = "cpufeatures"
 version = "0.2.17"
diff --git a/Cargo.toml b/Cargo.toml
index cf8ac35..ee29985 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,5 +2,6 @@
 resolver = "2"
 members = [
     "ascon",
+    "bash-f",
     "keccak",
 ]
diff --git a/bash-f/CHANGELOG.md b/bash-f/CHANGELOG.md
new file mode 100644
index 0000000..7c2ac0d
--- /dev/null
+++ b/bash-f/CHANGELOG.md
@@ -0,0 +1,11 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## 0.1.0 (UNRELEASED)
+- Initial release ([#92])
+
+[#92]: (https://github.com/RustCrypto/sponges/pull/92)
\ No newline at end of file
diff --git a/bash-f/Cargo.toml b/bash-f/Cargo.toml
new file mode 100644
index 0000000..1d105aa
--- /dev/null
+++ b/bash-f/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "bash-f"
+version = "0.1.0-rc.0"
+description = "Pure Rust implementation of the bash-f sponge function defined in STB 34.101.77-2020"
+license = "Apache-2.0 OR MIT"
+authors = ["RustCrypto Developers"]
+documentation = "https://docs.rs/bash"
+homepage = "https://github.com/RustCrypto/sponges/tree/master/bash"
+repository = "https://github.com/RustCrypto/sponges"
+keywords = ["bash", "belt", "permutation"]
+categories = ["cryptography", "no-std"]
+readme = "README.md"
+edition = "2024"
+rust-version = "1.85"
diff --git a/bash-f/LICENSE-APACHE b/bash-f/LICENSE-APACHE
new file mode 100644
index 0000000..59aa0f4
--- /dev/null
+++ b/bash-f/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
+   the copyright owner that is granting the License.
+
+   "Legal Entity" shall mean the union of the acting entity and all
+   other entities that control, are controlled by, or are under common
+   control with that entity. For the purposes of this definition,
+   "control" means (i) the power, direct or indirect, to cause the
+   direction or management of such entity, whether by contract or
+   otherwise, or (ii) ownership of fifty percent (50%) or more of the
+   outstanding shares, or (iii) beneficial ownership of such entity.
+
+   "You" (or "Your") shall mean an individual or Legal Entity
+   exercising permissions granted by this License.
+
+   "Source" form shall mean the preferred form for making modifications,
+   including but not limited to software source code, documentation
+   source, and configuration files.
+
+   "Object" form shall mean any form resulting from mechanical
+   transformation or translation of a Source form, including but
+   not limited to compiled object code, generated documentation,
+   and conversions to other media types.
+
+   "Work" shall mean the work of authorship, whether in Source or
+   Object form, made available under the License, as indicated by a
+   copyright notice that is included in or attached to the work
+   (an example is provided in the Appendix below).
+
+   "Derivative Works" shall mean any work, whether in Source or Object
+   form, that is based on (or derived from) the Work and for which the
+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
+   separable from, or merely link (or bind by name) to the interfaces of,
+   the Work and Derivative Works thereof.
+
+   "Contribution" shall mean any work of authorship, including
+   the original version of the Work and any modifications or additions
+   to that Work or Derivative Works thereof, that is intentionally
+   submitted to Licensor for inclusion in the Work by the copyright owner
+   or by an individual or Legal Entity authorized to submit on behalf of
+   the copyright owner. For the purposes of this definition, "submitted"
+   means any form of electronic, verbal, or written communication sent
+   to the Licensor or its representatives, including but not limited to
+   communication on electronic mailing lists, source code control systems,
+   and issue tracking systems that are managed by, or on behalf of, the
+   Licensor for the purpose of discussing and improving the Work, but
+   excluding communication that is conspicuously marked or otherwise
+   designated in writing by the copyright owner as "Not a Contribution."
+
+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
+   subsequently incorporated within the Work.
+
+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   copyright license to reproduce, prepare Derivative Works of,
+   publicly display, publicly perform, sublicense, and distribute the
+   Work and such Derivative Works in Source or Object form.
+
+3. Grant of Patent License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   (except as stated in this section) patent license to make, have made,
+   use, offer to sell, sell, import, and otherwise transfer the Work,
+   where such license applies only to those patent claims licensable
+   by such Contributor that are necessarily infringed by their
+   Contribution(s) alone or by combination of their Contribution(s)
+   with the Work to which such Contribution(s) was submitted. If You
+   institute patent litigation against any entity (including a
+   cross-claim or counterclaim in a lawsuit) alleging that the Work
+   or a Contribution incorporated within the Work constitutes direct
+   or contributory patent infringement, then any patent licenses
+   granted to You under this License for that Work shall terminate
+   as of the date such litigation is filed.
+
+4. Redistribution. You may reproduce and distribute copies of the
+   Work or Derivative Works thereof in any medium, with or without
+   modifications, and in Source or Object form, provided that You
+   meet the following conditions:
+
+   (a) You must give any other recipients of the Work or
+       Derivative Works a copy of this License; and
+
+   (b) You must cause any modified files to carry prominent notices
+       stating that You changed the files; and
+
+   (c) You must retain, in the Source form of any Derivative Works
+       that You distribute, all copyright, patent, trademark, and
+       attribution notices from the Source form of the Work,
+       excluding those notices that do not pertain to any part of
+       the Derivative Works; and
+
+   (d) If the Work includes a "NOTICE" text file as part of its
+       distribution, then any Derivative Works that You distribute must
+       include a readable copy of the attribution notices contained
+       within such NOTICE file, excluding those notices that do not
+       pertain to any part of the Derivative Works, in at least one
+       of the following places: within a NOTICE text file distributed
+       as part of the Derivative Works; within the Source form or
+       documentation, if provided along with the Derivative Works; or,
+       within a display generated by the Derivative Works, if and
+       wherever such third-party notices normally appear. The contents
+       of the NOTICE file are for informational purposes only and
+       do not modify the License. You may add Your own attribution
+       notices within Derivative Works that You distribute, alongside
+       or as an addendum to the NOTICE text from the Work, provided
+       that such additional attribution notices cannot be construed
+       as modifying the License.
+
+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
+   for any such Derivative Works as a whole, provided Your use,
+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+   Notwithstanding the above, nothing herein shall supersede or modify
+   the terms of any separate license agreement you may have executed
+   with Licensor regarding such Contributions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
+   except as required for reasonable and customary use in describing the
+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
+   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+   PARTICULAR PURPOSE. You are solely responsible for determining the
+   appropriateness of using or redistributing the Work and assume any
+   risks associated with Your exercise of permissions under this License.
+
+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
+   incurred by, or claims asserted against, such Contributor by reason
+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+   To apply the Apache License to your work, attach the following
+   boilerplate notice, with the fields enclosed by brackets "[]"
+   replaced with your own identifying information. (Don't include
+   the brackets!)  The text should be enclosed in the appropriate
+   comment syntax for the file format. We also recommend that a
+   file or class name and description of purpose be included on the
+   same "printed page" as the copyright notice for easier
+   identification within third-party archives.
+
+Copyright 2025 The RustCrypto Project Developers
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
\ No newline at end of file
diff --git a/bash-f/LICENSE-MIT b/bash-f/LICENSE-MIT
new file mode 100644
index 0000000..3b2f02c
--- /dev/null
+++ b/bash-f/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2025 The RustCrypto Project Developers
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
\ No newline at end of file
diff --git a/bash-f/README.md b/bash-f/README.md
new file mode 100644
index 0000000..8c8b510
--- /dev/null
+++ b/bash-f/README.md
@@ -0,0 +1,58 @@
+# RustCrypto: bash-f
+
+[![crate][crate-image]][crate-link]
+[![Docs][docs-image]][docs-link]
+![Apache2/MIT licensed][license-image]
+![Rust Version][rustc-image]
+[![Project Chat][chat-image]][chat-link]
+[![Build Status][build-image]][build-link]
+
+# BelHash - [STB 34.101.77-2020] Sponge-Based Cryptographic Algorithms
+
+This module implements the cryptographic algorithms defined in the Belarusian
+state standard STB 34.101.77-2020 "Sponge-based cryptographic algorithms".
+
+## Overview
+
+The standard defines a family of cryptographic algorithms built on a sponge
+construction with the `bash-f` sponge function at its core. The sponge function
+operates on 1536-bit (192-byte) states.
+
+## Security Notes
+
+No security audits of this crate have ever been performed, and it has not been thoroughly assessed to ensure its operation is constant-time on common CPU architectures.
+
+USE AT YOUR OWN RISK!
+
+## License
+
+Licensed under either of:
+
+* [Apache License, Version 2.0](https://www.apache.org/licenses/LICENSE-2.0)
+* [MIT license](https://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.
+
+[//]: # (badges)
+
+[crate-image]: https://buildstats.info/crate/bash-f
+[crate-link]: https://crates.io/crates/bash-f
+[docs-image]: https://docs.rs/bash-f/badge.svg
+[docs-link]: https://docs.rs/bash-f/
+[license-image]: https://img.shields.io/badge/license-Apache2.0/MIT-blue.svg
+[rustc-image]: https://img.shields.io/badge/rustc-1.85+-blue.svg
+[chat-image]: https://img.shields.io/badge/zulip-join_chat-blue.svg
+[chat-link]: https://rustcrypto.zulipchat.com/#narrow/stream/260038-AEADs
+[downloads-image]: https://img.shields.io/crates/d/chacha20poly1305.svg
+[build-image]: https://github.com/RustCrypto/AEADs/workflows/bash-f/badge.svg?branch=master&event=push
+[build-link]: https://github.com/RustCrypto/AEADs/actions
+
+[//]: # (general links)
+
+[STB 34.101.77-2020]: https://apmi.bsu.by/assets/files/std/bash-spec241.pdf
\ No newline at end of file
diff --git a/bash-f/benches/mod.rs b/bash-f/benches/mod.rs
new file mode 100644
index 0000000..1fd2a38
--- /dev/null
+++ b/bash-f/benches/mod.rs
@@ -0,0 +1,36 @@
+#![feature(test)]
+extern crate test;
+
+use bash_f::{STATE_WORDS, bash_f};
+use test::Bencher;
+
+#[bench]
+fn bench_bash_f(b: &mut Bencher) {
+    let mut state = [0u64; STATE_WORDS];
+    b.iter(|| {
+        bash_f(test::black_box(&mut state));
+        test::black_box(&state);
+    });
+}
+
+#[bench]
+fn bench_bash_f_10_rounds(b: &mut Bencher) {
+    let mut state = [0u64; STATE_WORDS];
+    b.iter(|| {
+        for _ in 0..10 {
+            bash_f(test::black_box(&mut state));
+        }
+        test::black_box(&state);
+    });
+}
+
+#[bench]
+fn bench_bash_f_100_rounds(b: &mut Bencher) {
+    let mut state = [0u64; STATE_WORDS];
+    b.iter(|| {
+        for _ in 0..100 {
+            bash_f(test::black_box(&mut state));
+        }
+        test::black_box(&state);
+    });
+}
diff --git a/bash-f/src/lib.rs b/bash-f/src/lib.rs
new file mode 100644
index 0000000..cb578db
--- /dev/null
+++ b/bash-f/src/lib.rs
@@ -0,0 +1,143 @@
+#![no_std]
+#![doc = include_str!("../README.md")]
+#![doc(
+    html_logo_url = "https://raw.githubusercontent.com/RustCrypto/meta/master/logo.svg",
+    html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/meta/master/logo.svg"
+)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![warn(missing_docs)]
+
+/// Number of 64-bit words in the state
+pub const STATE_WORDS: usize = 24;
+
+/// `bash-s` transformation.
+///
+/// Implements the S-box transformation defined in Section 6.1 of STB 34.101.77-2020.
+/// This is the core non-linear transformation used in the `bash-f` sponge function.
+fn bash_s(
+    mut w0: u64,
+    mut w1: u64,
+    mut w2: u64,
+    m1: u32,
+    n1: u32,
+    m2: u32,
+    n2: u32,
+) -> (u64, u64, u64) {
+    // 1. T0 ← RotHi^m1(W0)
+    let t0 = w0.rotate_left(m1);
+
+    // 2. W0 ← W0 ⊕ W1 ⊕ W2
+    w0 ^= w1 ^ w2;
+
+    // 3. T1 ← W1 ⊕ RotHi^n1(W0)
+    let t1 = w1 ^ w0.rotate_left(n1);
+
+    // 4. W1 ← T0 ⊕ T1
+    w1 = t0 ^ t1;
+
+    // 5. W2 ← W2 ⊕ RotHi^m2(W2) ⊕ RotHi^n2(T1)
+    w2 ^= w2.rotate_left(m2) ^ t1.rotate_left(n2);
+
+    // 6. T0 ← ¬W2
+    let t0 = !w2;
+
+    // 7. T1 ← W0 ∨ W2
+    let t1 = w0 | w2;
+
+    // 8. T2 ← W0 ∧ W1
+    let t2 = w0 & w1;
+
+    // 9. T0 ← T0 ∨ W1
+    let t0 = t0 | w1;
+
+    // 10. W1 ← W1 ⊕ T1
+    w1 ^= t1;
+
+    // 11. W2 ← W2 ⊕ T2
+    w2 ^= t2;
+
+    // 12. W0 ← W0 ⊕ T0
+    w0 ^= t0;
+
+    // 13. Return (W0, W1, W2)
+    (w0, w1, w2)
+}
+
+/// `bash-f` sponge permutation.
+///
+/// Implements the core sponge function defined in Section 6.2 of STB 34.101.77-2020.
+/// This is a cryptographic permutation that operates on 1536-bit states.
+///
+/// # Parameters
+///
+/// - `state`: Mutable reference to 24 × 64-bit words (1536 bits total)
+pub fn bash_f(state: &mut [u64; STATE_WORDS]) {
+    // 1. Split S into words (S0, S1, ..., S23)
+
+    // 2. C ← B194BAC80A08F53B (initialize round constant, swapped to little-endian)
+    let mut c: u64 = 0x3BF5080AC8BA94B1;
+
+    // 3. For i = 1, 2, ..., 24 perform 24 rounds
+    for _ in 0..STATE_WORDS {
+        // 3.1. Apply S-box layer with varying rotation parameters
+        // (m1, n1, m2, n2) ← (8, 53, 14, 1)
+        let (mut m1, mut n1, mut m2, mut n2) = (8, 53, 14, 1);
+
+        // 3.2. For j = 0, 1, ..., 7 apply bash-s to each of 8 columns
+        for j in 0..8 {
+            // 3.2.a. (Sj, S8+j, S16+j) ← bash-s(Sj, S8+j, S16+j, m1, n1, m2, n2)
+            let (s0, s1, s2) = bash_s(state[j], state[8 + j], state[16 + j], m1, n1, m2, n2);
+            state[j] = s0;
+            state[8 + j] = s1;
+            state[16 + j] = s2;
+
+            // 3.2.b. (m1, n1, m2, n2) ← (7·m1 mod 64, 7·n1 mod 64, 7·m2 mod 64, 7·n2 mod 64)
+            (m1, n1, m2, n2) = ((7 * m1) % 64, (7 * n1) % 64, (7 * m2) % 64, (7 * n2) % 64);
+        }
+
+        // 3.3. Apply word permutation
+        // S ← S15 ‖ S10 ‖ S9 ‖ S12 ‖ S11 ‖ S14 ‖ S13 ‖ S8 ‖
+        //     S17 ‖ S16 ‖ S19 ‖ S18 ‖ S21 ‖ S20 ‖ S23 ‖ S22 ‖
+        //     S6 ‖ S3 ‖ S0 ‖ S5 ‖ S2 ‖ S7 ‖ S4 ‖ S1
+        const INDEXES: [usize; STATE_WORDS] = [
+            15, 10, 9, 12, 11, 14, 13, 8, 17, 16, 19, 18, 21, 20, 23, 22, 6, 3, 0, 5, 2, 7, 4, 1,
+        ];
+        *state = INDEXES.map(|i| state[i]);
+
+        // 3.4. S23 ← S23 ⊕ C (add round constant)
+        state[23] ^= c;
+
+        // 3.5. Update LFSR (Galois configuration)
+        // if ⌊C⌉ is even, then C ← ShLo(C)
+        // else C ← ShLo(C) ⊕ AED8E07F99E12BDC
+        if c & 1 == 0 {
+            c >>= 1;
+        } else {
+            c = (c >> 1) ^ 0xDC2BE1997FE0D8AE;
+        }
+    }
+
+    // 4. Return S - state is modified in place
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Test vector from Table A.1 of STB 34.101.77-2020.
+    #[test]
+    fn test_bash_s_table_a1() {
+        // Constants in the spec are given using LE order
+        // For example, in spec when they write B194BAC80A08F53B, they do not mean 0xB194BAC80A08F53B, but 0x3BF5080AC8BA94B1.
+        // https://github.com/RustCrypto/sponges/pull/92#issuecomment-3433315011
+        let w0 = 0xB194BAC80A08F53Bu64.swap_bytes();
+        let w1 = 0xE12BDC1AE28257ECu64.swap_bytes();
+        let w2 = 0xE9DEE72C8F0C0FA6u64.swap_bytes();
+
+        let (w0_out, w1_out, w2_out) = bash_s(w0, w1, w2, 8, 53, 14, 1);
+
+        assert_eq!(w0_out, 0x479E76129979DC5Fu64.swap_bytes());
+        assert_eq!(w1_out, 0x0F2B2C93ED128EDDu64.swap_bytes());
+        assert_eq!(w2_out, 0x41009B1B112DFEF3u64.swap_bytes());
+    }
+}
diff --git a/bash-f/tests/bash.rs b/bash-f/tests/bash.rs
new file mode 100644
index 0000000..95ad5df
--- /dev/null
+++ b/bash-f/tests/bash.rs
@@ -0,0 +1,70 @@
+use bash_f::bash_f;
+
+/// Test vector from Table A.2 of STB 34.101.77-2020.
+#[test]
+fn test_bash_f_table_a2() {
+    let input: [u64; 24] = [
+        0xB194BAC80A08F53B,
+        0x366D008E584A5DE4,
+        0x8504FA9D1BB6C7AC,
+        0x252E72C202FDCE0D,
+        0x5BE3D61217B96181,
+        0xFE6786AD716B890B,
+        0x5CB0C0FF33C356B8,
+        0x35C405AED8E07F99,
+        0xE12BDC1AE28257EC,
+        0x703FCCF095EE8DF1,
+        0xC1AB76389FE678CA,
+        0xF7C6F860D5BB9C4F,
+        0xF33C657B637C306A,
+        0xDD4EA7799EB23D31,
+        0x3E98B56E27D3BCCF,
+        0x591E181F4C5AB793,
+        0xE9DEE72C8F0C0FA6,
+        0x2DDB49F46F739647,
+        0x06075316ED247A37,
+        0x39CBA38303A98BF6,
+        0x92BD9B1CE5D14101,
+        0x5445FBC95E4D0EF2,
+        0x682080AA227D642F,
+        0x2687F93490405511,
+    ];
+
+    let expected: [u64; 24] = [
+        0x8FE727775EA7F140,
+        0xB95BB6A200CBB28C,
+        0x7F0809C0C0BC68B7,
+        0xDC5AEDC841BD94E4,
+        0x03630C301FC255DF,
+        0x5B67DB53EF65E376,
+        0xE8A4D797A6172F22,
+        0x71BA48093173D329,
+        0xC3502AC946767326,
+        0xA2891971392D3F70,
+        0x89959F5D61621238,
+        0x655975E00E2132A0,
+        0xD5018CEEDB17731C,
+        0xCD88FC50151D37C0,
+        0xD4A3359506AEDC2E,
+        0x6109511E7703AFBB,
+        0x014642348D8568AA,
+        0x1A5D9868C4C7E6DF,
+        0xA756B1690C7C2608,
+        0xA2DC136F5997AB8F,
+        0xBB3F4D9F033C87CA,
+        0x6070E117F099C409,
+        0x4972ACD9D976214B,
+        0x7CED8E3F8B6E058E,
+    ];
+
+    // Constants in the spec are given using LE order
+    // For example, in spec when they write B194BAC80A08F53B, they do not mean 0xB194BAC80A08F53B, but 0x3BF5080AC8BA94B1.
+    // https://github.com/RustCrypto/sponges/pull/92#issuecomment-3433315011
+    let mut state = input.map(|x| x.swap_bytes());
+
+    bash_f(&mut state);
+
+    let output = state.map(|x| x.swap_bytes());
+
+    assert_eq!(output, expected);
+}