diff --git a/lib/std/crypto/benchmark.zig b/lib/std/crypto/benchmark.zig
index 9b6056370c..f295276210 100644
--- a/lib/std/crypto/benchmark.zig
+++ b/lib/std/crypto/benchmark.zig
@@ -30,6 +30,7 @@ const hashes = [_]Crypto{
     Crypto{ .ty = crypto.hash.sha3.Shake256, .name = "shake-256" },
     Crypto{ .ty = crypto.hash.sha3.TurboShake128(null), .name = "turboshake-128" },
     Crypto{ .ty = crypto.hash.sha3.TurboShake256(null), .name = "turboshake-256" },
+    Crypto{ .ty = crypto.hash.sha3.KT128, .name = "kt128" },
     Crypto{ .ty = crypto.hash.blake2.Blake2s256, .name = "blake2s" },
     Crypto{ .ty = crypto.hash.blake2.Blake2b512, .name = "blake2b" },
     Crypto{ .ty = crypto.hash.Blake3, .name = "blake3" },
@@ -37,6 +38,7 @@ const hashes = [_]Crypto{
 
 const parallel_hashes = [_]Crypto{
     Crypto{ .ty = crypto.hash.Blake3, .name = "blake3-parallel" },
+    Crypto{ .ty = crypto.hash.sha3.KT128, .name = "kt128-parallel" },
 };
 
 const block_size: usize = 8 * 8192;
diff --git a/lib/std/crypto/kangarootwelve.zig b/lib/std/crypto/kangarootwelve.zig
new file mode 100644
index 0000000000..8c784aaa1d
--- /dev/null
+++ b/lib/std/crypto/kangarootwelve.zig
@@ -0,0 +1,1647 @@
+const std = @import("std");
+const builtin = @import("builtin");
+const crypto = std.crypto;
+const Allocator = std.mem.Allocator;
+
+const TurboSHAKE128State = crypto.hash.sha3.TurboShake128(0x06);
+const TurboSHAKE256State = crypto.hash.sha3.TurboShake256(0x06);
+
+const chunk_size: usize = 8192; // Chunk size for tree hashing (8 KiB)
+const cache_line_size = std.atomic.cache_line;
+
+// Optimal SIMD vector length for u64 on this target platform
+const optimal_vector_len = std.simd.suggestVectorLength(u64) orelse 1;
+
+// Round constants for Keccak-p[1600,12]
+const RC = [12]u64{
+    0x000000008000808B,
+    0x800000000000008B,
+    0x8000000000008089,
+    0x8000000000008003,
+    0x8000000000008002,
+    0x8000000000000080,
+    0x000000000000800A,
+    0x800000008000000A,
+    0x8000000080008081,
+    0x8000000000008080,
+    0x0000000080000001,
+    0x8000000080008008,
+};
+
+/// Generic KangarooTwelve variant builder.
+/// Creates a variant type with specific cryptographic parameters.
+fn KangarooVariant(
+    comptime security_level_bits: comptime_int,
+    comptime rate_bytes: usize,
+    comptime cv_size_bytes: usize,
+    comptime StateTypeParam: type,
+    comptime sep_x: usize,
+    comptime sep_y: usize,
+    comptime pad_x: usize,
+    comptime pad_y: usize,
+    comptime toBufferFn: fn (*const MultiSliceView, u8, []u8) void,
+    comptime allocFn: fn (Allocator, *const MultiSliceView, u8, usize) anyerror![]u8,
+) type {
+    return struct {
+        const security_level = security_level_bits;
+        const rate = rate_bytes;
+        const rate_in_lanes = rate_bytes / 8;
+        const cv_size = cv_size_bytes;
+        const StateType = StateTypeParam;
+        const separation_byte_pos = .{ .x = sep_x, .y = sep_y };
+        const padding_pos = .{ .x = pad_x, .y = pad_y };
+
+        inline fn turboShakeToBuffer(view: *const MultiSliceView, separation_byte: u8, output: []u8) void {
+            toBufferFn(view, separation_byte, output);
+        }
+
+        inline fn turboShakeMultiSliceAlloc(
+            allocator: Allocator,
+            view: *const MultiSliceView,
+            separation_byte: u8,
+            output_len: usize,
+        ) ![]u8 {
+            return allocFn(allocator, view, separation_byte, output_len);
+        }
+    };
+}
+
+/// KangarooTwelve with 128-bit security parameters
+const KT128Variant = KangarooVariant(
+    128, // Security level in bits
+    168, // TurboSHAKE128 rate in bytes
+    32, // Chaining value size in bytes
+    TurboSHAKE128State,
+    1, // separation_byte_pos.x (lane 11: 88 bytes into 168-byte rate)
+    3, // separation_byte_pos.y
+    0, // padding_pos.x (lane 20: last lane of 168-byte rate)
+    4, // padding_pos.y
+    turboShake128MultiSliceToBuffer,
+    turboShake128MultiSlice,
+);
+
+/// KangarooTwelve with 256-bit security parameters
+const KT256Variant = KangarooVariant(
+    256, // Security level in bits
+    136, // TurboSHAKE256 rate in bytes
+    64, // Chaining value size in bytes
+    TurboSHAKE256State,
+    4, // separation_byte_pos.x (lane 4: 32 bytes into 136-byte rate)
+    0, // separation_byte_pos.y
+    1, // padding_pos.x (lane 16: last lane of 136-byte rate)
+    3, // padding_pos.y
+    turboShake256MultiSliceToBuffer,
+    turboShake256MultiSlice,
+);
+
+/// Rotate left for u64 vector
+inline fn rol64Vec(comptime N: usize, v: @Vector(N, u64), comptime n: u6) @Vector(N, u64) {
+    if (n == 0) return v;
+    const left: @Vector(N, u64) = @splat(n);
+    const right_shift: u64 = 64 - @as(u64, n);
+    const right: @Vector(N, u64) = @splat(right_shift);
+    return (v << left) | (v >> right);
+}
+
+/// Load a 64-bit little-endian value
+inline fn load64(bytes: []const u8) u64 {
+    return std.mem.readInt(u64, bytes[0..8], .little);
+}
+
+/// Store a 64-bit little-endian value
+inline fn store64(value: u64, bytes: []u8) void {
+    std.mem.writeInt(u64, bytes[0..8], value, .little);
+}
+
+/// Right-encode result type (max 9 bytes for 64-bit usize)
+const RightEncoded = struct {
+    bytes: [9]u8,
+    len: u8,
+
+    fn slice(self: *const RightEncoded) []const u8 {
+        return self.bytes[0..self.len];
+    }
+};
+
+/// Right-encode: encodes a number as bytes with length suffix (no allocation)
+fn rightEncode(x: usize) RightEncoded {
+    var result: RightEncoded = undefined;
+
+    if (x == 0) {
+        result.bytes[0] = 0;
+        result.len = 1;
+        return result;
+    }
+
+    var temp: [9]u8 = undefined;
+    var len: usize = 0;
+    var val = x;
+
+    while (val > 0) : (val /= 256) {
+        temp[len] = @intCast(val % 256);
+        len += 1;
+    }
+
+    // Reverse bytes (MSB first)
+    for (0..len) |i| {
+        result.bytes[i] = temp[len - 1 - i];
+    }
+    result.bytes[len] = @intCast(len);
+    result.len = @intCast(len + 1);
+
+    return result;
+}
+
+/// Virtual contiguous view over multiple slices (zero-copy)
+const MultiSliceView = struct {
+    slices: [3][]const u8,
+    offsets: [4]usize,
+
+    fn init(s1: []const u8, s2: []const u8, s3: []const u8) MultiSliceView {
+        return .{
+            .slices = .{ s1, s2, s3 },
+            .offsets = .{
+                0,
+                s1.len,
+                s1.len + s2.len,
+                s1.len + s2.len + s3.len,
+            },
+        };
+    }
+
+    fn totalLen(self: *const MultiSliceView) usize {
+        return self.offsets[3];
+    }
+
+    /// Get byte at position (zero-copy)
+    fn getByte(self: *const MultiSliceView, pos: usize) u8 {
+        for (0..3) |i| {
+            if (pos >= self.offsets[i] and pos < self.offsets[i + 1]) {
+                return self.slices[i][pos - self.offsets[i]];
+            }
+        }
+        unreachable;
+    }
+
+    /// Try to get a contiguous slice [start..end) - returns null if spans boundaries
+    fn tryGetSlice(self: *const MultiSliceView, start: usize, end: usize) ?[]const u8 {
+        for (0..3) |i| {
+            if (start >= self.offsets[i] and end <= self.offsets[i + 1]) {
+                const local_start = start - self.offsets[i];
+                const local_end = end - self.offsets[i];
+                return self.slices[i][local_start..local_end];
+            }
+        }
+        return null;
+    }
+
+    /// Copy range [start..end) to buffer (used when slice spans boundaries)
+    fn copyRange(self: *const MultiSliceView, start: usize, end: usize, buffer: []u8) void {
+        var pos: usize = 0;
+        for (start..end) |i| {
+            buffer[pos] = self.getByte(i);
+            pos += 1;
+        }
+    }
+};
+
+/// Apply Keccak-p[1600,12] to N states using SIMD
+fn keccakP1600timesN(comptime N: usize, states: *[5][5]@Vector(N, u64)) void {
+    @setEvalBranchQuota(10000);
+
+    // Pre-computed rotation offsets for rho-pi step
+    const rho_offsets = comptime blk: {
+        var offsets: [24]u6 = undefined;
+        var px: usize = 1;
+        var py: usize = 0;
+        for (0..24) |t| {
+            const rot_amount = ((t + 1) * (t + 2) / 2) % 64;
+            offsets[t] = @intCast(rot_amount);
+            const temp_x = py;
+            py = (2 * px + 3 * py) % 5;
+            px = temp_x;
+        }
+        break :blk offsets;
+    };
+
+    var round: usize = 0;
+    while (round < 12) : (round += 2) {
+        inline for (0..2) |i| {
+            // θ (theta)
+            var C: [5]@Vector(N, u64) = undefined;
+            inline for (0..5) |x| {
+                C[x] = states[x][0] ^ states[x][1] ^ states[x][2] ^ states[x][3] ^ states[x][4];
+            }
+
+            var D: [5]@Vector(N, u64) = undefined;
+            inline for (0..5) |x| {
+                D[x] = C[(x + 4) % 5] ^ rol64Vec(N, C[(x + 1) % 5], 1);
+            }
+
+            // Apply D to all lanes
+            inline for (0..5) |x| {
+                states[x][0] ^= D[x];
+                states[x][1] ^= D[x];
+                states[x][2] ^= D[x];
+                states[x][3] ^= D[x];
+                states[x][4] ^= D[x];
+            }
+
+            // ρ (rho) and π (pi) - optimized with pre-computed offsets
+            var current = states[1][0];
+            var px: usize = 1;
+            var py: usize = 0;
+            inline for (rho_offsets) |rot| {
+                const next_y = (2 * px + 3 * py) % 5;
+                const next = states[py][next_y];
+                states[py][next_y] = rol64Vec(N, current, rot);
+                current = next;
+                px = py;
+                py = next_y;
+            }
+
+            // χ (chi) - optimized with better register usage
+            inline for (0..5) |y| {
+                const t0 = states[0][y];
+                const t1 = states[1][y];
+                const t2 = states[2][y];
+                const t3 = states[3][y];
+                const t4 = states[4][y];
+
+                states[0][y] = t0 ^ (~t1 & t2);
+                states[1][y] = t1 ^ (~t2 & t3);
+                states[2][y] = t2 ^ (~t3 & t4);
+                states[3][y] = t3 ^ (~t4 & t0);
+                states[4][y] = t4 ^ (~t0 & t1);
+            }
+
+            // ι (iota)
+            const rc_splat: @Vector(N, u64) = @splat(RC[round + i]);
+            states[0][0] ^= rc_splat;
+        }
+    }
+}
+
+/// Add lanes from data to N states in parallel with stride using SIMD
+fn addLanesAll(
+    comptime N: usize,
+    states: *[5][5]@Vector(N, u64),
+    data: []const u8,
+    lane_count: usize,
+    lane_offset: usize,
+) void {
+
+    // Process lanes (at most 25 lanes in Keccak state)
+    inline for (0..25) |xy| {
+        if (xy < lane_count) {
+            const x = xy % 5;
+            const y = xy / 5;
+
+            var loaded_data: @Vector(N, u64) = undefined;
+            inline for (0..N) |i| {
+                loaded_data[i] = load64(data[8 * (i * lane_offset + xy) ..]);
+            }
+            states[x][y] ^= loaded_data;
+        }
+    }
+}
+
+/// Apply Keccak-p[1600,12] to a single state (byte representation)
+fn keccakP(state: *[200]u8) void {
+    @setEvalBranchQuota(10000);
+    var lanes: [5][5]u64 = undefined;
+
+    // Load state into lanes
+    inline for (0..5) |x| {
+        inline for (0..5) |y| {
+            lanes[x][y] = load64(state[8 * (x + 5 * y) ..]);
+        }
+    }
+
+    // Apply 12 rounds
+    var round: usize = 0;
+    while (round < 12) : (round += 2) {
+        inline for (0..2) |i| {
+            // θ
+            var C: [5]u64 = undefined;
+            inline for (0..5) |x| {
+                C[x] = lanes[x][0] ^ lanes[x][1] ^ lanes[x][2] ^ lanes[x][3] ^ lanes[x][4];
+            }
+            var D: [5]u64 = undefined;
+            inline for (0..5) |x| {
+                D[x] = C[(x + 4) % 5] ^ std.math.rotl(u64, C[(x + 1) % 5], 1);
+            }
+            inline for (0..5) |x| {
+                inline for (0..5) |y| {
+                    lanes[x][y] ^= D[x];
+                }
+            }
+
+            // ρ and π
+            var current = lanes[1][0];
+            var px: usize = 1;
+            var py: usize = 0;
+            inline for (0..24) |t| {
+                const temp = lanes[py][(2 * px + 3 * py) % 5];
+                const rot_amount = ((t + 1) * (t + 2) / 2) % 64;
+                lanes[py][(2 * px + 3 * py) % 5] = std.math.rotl(u64, current, @as(u6, @intCast(rot_amount)));
+                current = temp;
+                const temp_x = py;
+                py = (2 * px + 3 * py) % 5;
+                px = temp_x;
+            }
+
+            // χ
+            inline for (0..5) |y| {
+                const T = [5]u64{ lanes[0][y], lanes[1][y], lanes[2][y], lanes[3][y], lanes[4][y] };
+                inline for (0..5) |x| {
+                    lanes[x][y] = T[x] ^ (~T[(x + 1) % 5] & T[(x + 2) % 5]);
+                }
+            }
+
+            // ι
+            lanes[0][0] ^= RC[round + i];
+        }
+    }
+
+    // Store lanes back to state
+    inline for (0..5) |x| {
+        inline for (0..5) |y| {
+            store64(lanes[x][y], state[8 * (x + 5 * y) ..]);
+        }
+    }
+}
+
+/// Apply Keccak-p[1600,12] to a single state (u64 lane representation)
+fn keccakPLanes(lanes: *[25]u64) void {
+    @setEvalBranchQuota(10000);
+
+    // Apply 12 rounds
+    inline for (RC) |rc| {
+        // θ
+        var C: [5]u64 = undefined;
+        inline for (0..5) |x| {
+            C[x] = lanes[x] ^ lanes[x + 5] ^ lanes[x + 10] ^ lanes[x + 15] ^ lanes[x + 20];
+        }
+        var D: [5]u64 = undefined;
+        inline for (0..5) |x| {
+            D[x] = C[(x + 4) % 5] ^ std.math.rotl(u64, C[(x + 1) % 5], 1);
+        }
+        inline for (0..5) |x| {
+            inline for (0..5) |y| {
+                lanes[x + 5 * y] ^= D[x];
+            }
+        }
+
+        // ρ and π
+        var current = lanes[1];
+        var px: usize = 1;
+        var py: usize = 0;
+        inline for (0..24) |t| {
+            const next_y = (2 * px + 3 * py) % 5;
+            const next_idx = py + 5 * next_y;
+            const temp = lanes[next_idx];
+            const rot_amount = ((t + 1) * (t + 2) / 2) % 64;
+            lanes[next_idx] = std.math.rotl(u64, current, @as(u6, @intCast(rot_amount)));
+            current = temp;
+            px = py;
+            py = next_y;
+        }
+
+        // χ
+        inline for (0..5) |y| {
+            const idx = 5 * y;
+            const T = [5]u64{ lanes[idx], lanes[idx + 1], lanes[idx + 2], lanes[idx + 3], lanes[idx + 4] };
+            inline for (0..5) |x| {
+                lanes[idx + x] = T[x] ^ (~T[(x + 1) % 5] & T[(x + 2) % 5]);
+            }
+        }
+
+        // ι
+        lanes[0] ^= rc;
+    }
+}
+
+/// Generic non-allocating TurboSHAKE: write output to provided buffer
+fn turboShakeMultiSliceToBuffer(
+    comptime rate: usize,
+    view: *const MultiSliceView,
+    separation_byte: u8,
+    output: []u8,
+) void {
+    var state: [200]u8 = @splat(0);
+    var state_pos: usize = 0;
+
+    // Absorb all bytes from the multi-slice view
+    const total = view.totalLen();
+    var pos: usize = 0;
+    while (pos < total) {
+        state[state_pos] ^= view.getByte(pos);
+        state_pos += 1;
+        pos += 1;
+
+        if (state_pos == rate) {
+            keccakP(&state);
+            state_pos = 0;
+        }
+    }
+
+    // Add separation byte and padding
+    state[state_pos] ^= separation_byte;
+    state[rate - 1] ^= 0x80;
+    keccakP(&state);
+
+    // Squeeze
+    var out_offset: usize = 0;
+    while (out_offset < output.len) {
+        const chunk = @min(rate, output.len - out_offset);
+        @memcpy(output[out_offset..][0..chunk], state[0..chunk]);
+        out_offset += chunk;
+        if (out_offset < output.len) {
+            keccakP(&state);
+        }
+    }
+}
+
+/// Generic allocating TurboSHAKE
+fn turboShakeMultiSlice(
+    comptime rate: usize,
+    allocator: Allocator,
+    view: *const MultiSliceView,
+    separation_byte: u8,
+    output_len: usize,
+) ![]u8 {
+    const output = try allocator.alloc(u8, output_len);
+    turboShakeMultiSliceToBuffer(rate, view, separation_byte, output);
+    return output;
+}
+
+/// Non-allocating TurboSHAKE128: write output to provided buffer
+fn turboShake128MultiSliceToBuffer(
+    view: *const MultiSliceView,
+    separation_byte: u8,
+    output: []u8,
+) void {
+    turboShakeMultiSliceToBuffer(168, view, separation_byte, output);
+}
+
+/// Allocating TurboSHAKE128
+fn turboShake128MultiSlice(
+    allocator: Allocator,
+    view: *const MultiSliceView,
+    separation_byte: u8,
+    output_len: usize,
+) ![]u8 {
+    return turboShakeMultiSlice(168, allocator, view, separation_byte, output_len);
+}
+
+/// Non-allocating TurboSHAKE256: write output to provided buffer
+fn turboShake256MultiSliceToBuffer(
+    view: *const MultiSliceView,
+    separation_byte: u8,
+    output: []u8,
+) void {
+    turboShakeMultiSliceToBuffer(136, view, separation_byte, output);
+}
+
+/// Allocating TurboSHAKE256
+fn turboShake256MultiSlice(
+    allocator: Allocator,
+    view: *const MultiSliceView,
+    separation_byte: u8,
+    output_len: usize,
+) ![]u8 {
+    return turboShakeMultiSlice(136, allocator, view, separation_byte, output_len);
+}
+
+/// Process N leaves (8KiB chunks) in parallel - generic version
+fn processLeaves(
+    comptime Variant: type,
+    comptime N: usize,
+    data: []const u8,
+    result: *[N * Variant.cv_size]u8,
+) void {
+    const rate_in_lanes: usize = Variant.rate_in_lanes;
+    const rate_in_bytes: usize = rate_in_lanes * 8;
+    const cv_size: usize = Variant.cv_size;
+
+    // Initialize N all-zero states with cache alignment
+    var states: [5][5]@Vector(N, u64) align(cache_line_size) = undefined;
+    inline for (0..5) |x| {
+        inline for (0..5) |y| {
+            states[x][y] = @splat(0);
+        }
+    }
+
+    // Process complete blocks
+    var j: usize = 0;
+    while (j + rate_in_bytes <= chunk_size) : (j += rate_in_bytes) {
+        addLanesAll(N, &states, data[j..], rate_in_lanes, chunk_size / 8);
+        keccakP1600timesN(N, &states);
+    }
+
+    // Process last incomplete block
+    const remaining_lanes = (chunk_size - j) / 8;
+    if (remaining_lanes > 0) {
+        addLanesAll(N, &states, data[j..], remaining_lanes, chunk_size / 8);
+    }
+
+    // Add suffix 0x0B and padding
+    const suffix_pos = Variant.separation_byte_pos;
+    const padding_pos = Variant.padding_pos;
+
+    const suffix_splat: @Vector(N, u64) = @splat(0x0B);
+    states[suffix_pos.x][suffix_pos.y] ^= suffix_splat;
+    const padding_splat: @Vector(N, u64) = @splat(0x8000000000000000);
+    states[padding_pos.x][padding_pos.y] ^= padding_splat;
+
+    keccakP1600timesN(N, &states);
+
+    // Extract chaining values from each state
+    const lanes_to_extract = cv_size / 8;
+    comptime var lane_idx: usize = 0;
+    inline while (lane_idx < lanes_to_extract) : (lane_idx += 1) {
+        const x = lane_idx % 5;
+        const y = lane_idx / 5;
+        inline for (0..N) |i| {
+            store64(states[x][y][i], result[i * cv_size + lane_idx * 8 ..]);
+        }
+    }
+}
+
+/// Helper function to process N leaves in parallel, reducing code duplication
+inline fn processNLeaves(
+    comptime Variant: type,
+    comptime N: usize,
+    view: *const MultiSliceView,
+    j: usize,
+    leaf_buffer: []u8,
+    output: []align(@alignOf(u64)) u8,
+) void {
+    const cv_size = Variant.cv_size;
+    comptime std.debug.assert(cv_size % @sizeOf(u64) == 0);
+
+    if (view.tryGetSlice(j, j + N * chunk_size)) |leaf_data| {
+        var leaf_cvs: [N * cv_size]u8 = undefined;
+        processLeaves(Variant, N, leaf_data, &leaf_cvs);
+        @memcpy(output[0..leaf_cvs.len], &leaf_cvs);
+    } else {
+        view.copyRange(j, j + N * chunk_size, leaf_buffer[0 .. N * chunk_size]);
+        var leaf_cvs: [N * cv_size]u8 = undefined;
+        processLeaves(Variant, N, leaf_buffer[0 .. N * chunk_size], &leaf_cvs);
+        @memcpy(output[0..leaf_cvs.len], &leaf_cvs);
+    }
+}
+
+/// Helper to process N leaves in SIMD and absorb CVs into state
+inline fn processAndAbsorbNLeaves(
+    comptime Variant: type,
+    comptime N: usize,
+    view: *const MultiSliceView,
+    j: usize,
+    leaf_buffer: []u8,
+    final_state: anytype,
+) void {
+    const cv_size = Variant.cv_size;
+    if (view.tryGetSlice(j, j + N * chunk_size)) |leaf_data| {
+        var leaf_cvs: [N * cv_size]u8 align(cache_line_size) = undefined;
+        processLeaves(Variant, N, leaf_data, &leaf_cvs);
+        final_state.update(&leaf_cvs);
+    } else {
+        view.copyRange(j, j + N * chunk_size, leaf_buffer[0 .. N * chunk_size]);
+        var leaf_cvs: [N * cv_size]u8 align(cache_line_size) = undefined;
+        processLeaves(Variant, N, leaf_buffer[0 .. N * chunk_size], &leaf_cvs);
+        final_state.update(&leaf_cvs);
+    }
+}
+
+/// Generic single-threaded implementation
+fn ktSingleThreaded(comptime Variant: type, view: *const MultiSliceView, total_len: usize, output: []u8) void {
+    const cv_size = Variant.cv_size;
+    const StateType = Variant.StateType;
+
+    // Initialize streaming TurboSHAKE state for final node (delimiter 0x06 is set in the type)
+    var final_state = StateType.init(.{});
+
+    // Absorb first B bytes from input
+    var first_b_buffer: [chunk_size]u8 = undefined;
+    if (view.tryGetSlice(0, chunk_size)) |first_chunk| {
+        final_state.update(first_chunk);
+    } else {
+        view.copyRange(0, chunk_size, &first_b_buffer);
+        final_state.update(&first_b_buffer);
+    }
+
+    // Absorb padding bytes (8 bytes: 0x03 followed by 7 zeros)
+    const padding = [_]u8{ 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+    final_state.update(&padding);
+
+    var j: usize = chunk_size;
+    var n: usize = 0;
+
+    // Temporary buffers for boundary-spanning leaves and CV computation
+    var leaf_buffer: [chunk_size * 8]u8 align(cache_line_size) = undefined;
+    var cv_buffer: [64]u8 = undefined; // Max CV size is 64 bytes
+
+    // Process leaves in SIMD batches (8x, 4x, 2x)
+    inline for ([_]usize{ 8, 4, 2 }) |batch_size| {
+        while (optimal_vector_len >= batch_size and j + batch_size * chunk_size <= total_len) {
+            processAndAbsorbNLeaves(Variant, batch_size, view, j, &leaf_buffer, &final_state);
+            j += batch_size * chunk_size;
+            n += batch_size;
+        }
+    }
+
+    // Process remaining leaves one at a time
+    while (j < total_len) {
+        const chunk_len = @min(chunk_size, total_len - j);
+        if (view.tryGetSlice(j, j + chunk_len)) |leaf_data| {
+            const cv_slice = MultiSliceView.init(leaf_data, &[_]u8{}, &[_]u8{});
+            Variant.turboShakeToBuffer(&cv_slice, 0x0B, cv_buffer[0..cv_size]);
+            final_state.update(cv_buffer[0..cv_size]); // Absorb CV immediately
+        } else {
+            view.copyRange(j, j + chunk_len, leaf_buffer[0..chunk_len]);
+            const cv_slice = MultiSliceView.init(leaf_buffer[0..chunk_len], &[_]u8{}, &[_]u8{});
+            Variant.turboShakeToBuffer(&cv_slice, 0x0B, cv_buffer[0..cv_size]);
+            final_state.update(cv_buffer[0..cv_size]);
+        }
+        j += chunk_size;
+        n += 1;
+    }
+
+    // Absorb right_encode(n) and terminator
+    const n_enc = rightEncode(n);
+    final_state.update(n_enc.slice());
+    const terminator = [_]u8{ 0xFF, 0xFF };
+    final_state.update(&terminator);
+
+    // Finalize and squeeze output
+    final_state.final(output);
+}
+
+/// Generic KangarooTwelve hash function builder.
+/// Creates a public API type with hash and hashParallel methods for a specific variant.
+fn KTHash(
+    comptime Variant: type,
+    comptime singleChunkFn: fn (*const MultiSliceView, u8, []u8) void,
+) type {
+    return struct {
+        const Self = @This();
+        const StateType = Variant.StateType;
+
+        /// The recommended output length, in bytes.
+        pub const digest_length = Variant.security_level / 8 * 2;
+        /// The block length, or rate, in bytes.
+        pub const block_length = Variant.rate;
+
+        /// Configuration options for KangarooTwelve hashing.
+        ///
+        /// Options include an optional customization string that provides domain separation,
+        /// ensuring that identical inputs with different customization strings
+        /// produce completely distinct hash outputs.
+        ///
+        /// This prevents hash collisions when the same data is hashed in different contexts.
+        ///
+        /// Customization strings can be of any length.
+        ///
+        /// Common options for customization::
+        ///
+        /// - Key derivation or MAC: 16-byte secret for KT128, 32-byte secret for KT256
+        /// - Context Separation: domain-specific strings (e.g., "email", "password", "session")
+        /// - Composite Keys: concatenation of secret key + context string
+        pub const Options = struct {
+            customization: ?[]const u8 = null,
+        };
+
+        // Message buffer (accumulates message data only, not customization)
+        buffer: [chunk_size]u8,
+        buffer_len: usize,
+        message_len: usize,
+
+        // Customization string (fixed at init)
+        customization: []const u8,
+        custom_len_enc: RightEncoded,
+
+        // Tree mode state (lazy initialization when buffer overflows first time)
+        first_chunk: ?[chunk_size]u8, // Saved first chunk for tree mode
+        final_state: ?StateType, // Running TurboSHAKE state for final node
+        num_leaves: usize, // Count of leaves processed (after first chunk)
+
+        // SIMD chunk batching
+        pending_chunks: [8 * chunk_size]u8 align(cache_line_size), // Buffer for up to 8 chunks
+        pending_count: usize, // Number of complete chunks in pending_chunks
+
+        /// Initialize a KangarooTwelve hashing context.
+        ///
+        /// Options include an optional customization string that provides domain separation,
+        /// ensuring that identical inputs with different customization strings
+        /// produce completely distinct hash outputs.
+        ///
+        /// This prevents hash collisions when the same data is hashed in different contexts.
+        ///
+        /// Customization strings can be of any length.
+        ///
+        /// Common options for customization::
+        ///
+        /// - Key derivation or MAC: 16-byte secret for KT128, 32-byte secret for KT256
+        /// - Context Separation: domain-specific strings (e.g., "email", "password", "session")
+        /// - Composite Keys: concatenation of secret key + context string
+        pub fn init(options: Options) Self {
+            const custom = options.customization orelse &[_]u8{};
+            return .{
+                .buffer = undefined,
+                .buffer_len = 0,
+                .message_len = 0,
+                .customization = custom,
+                .custom_len_enc = rightEncode(custom.len),
+                .first_chunk = null,
+                .final_state = null,
+                .num_leaves = 0,
+                .pending_chunks = undefined,
+                .pending_count = 0,
+            };
+        }
+
+        /// Flush all pending chunks using SIMD when possible
+        fn flushPendingChunks(self: *Self) void {
+            const cv_size = Variant.cv_size;
+
+            // Process all pending chunks using the largest SIMD batch sizes possible
+            while (self.pending_count > 0) {
+                // Try SIMD batches in decreasing size order
+                inline for ([_]usize{ 8, 4, 2 }) |batch_size| {
+                    if (optimal_vector_len >= batch_size and self.pending_count >= batch_size) {
+                        var leaf_cvs: [batch_size * cv_size]u8 align(cache_line_size) = undefined;
+                        processLeaves(Variant, batch_size, self.pending_chunks[0 .. batch_size * chunk_size], &leaf_cvs);
+                        self.final_state.?.update(&leaf_cvs);
+                        self.num_leaves += batch_size;
+                        self.pending_count -= batch_size;
+
+                        // Shift remaining chunks to the front
+                        if (self.pending_count > 0) {
+                            const remaining_bytes = self.pending_count * chunk_size;
+                            @memcpy(self.pending_chunks[0..remaining_bytes], self.pending_chunks[batch_size * chunk_size ..][0..remaining_bytes]);
+                        }
+                        break; // Continue outer loop to try next batch
+                    }
+                }
+
+                // If no SIMD batch was possible, process one chunk with scalar code
+                if (self.pending_count > 0 and self.pending_count < 2) {
+                    var cv_buffer: [64]u8 = undefined;
+                    const cv_slice = MultiSliceView.init(self.pending_chunks[0..chunk_size], &[_]u8{}, &[_]u8{});
+                    Variant.turboShakeToBuffer(&cv_slice, 0x0B, cv_buffer[0..cv_size]);
+                    self.final_state.?.update(cv_buffer[0..cv_size]);
+                    self.num_leaves += 1;
+                    self.pending_count -= 1;
+                    break; // No more chunks to process
+                }
+            }
+        }
+
+        /// Absorb data into the hash state.
+        /// Can be called multiple times to incrementally add data.
+        pub fn update(self: *Self, data: []const u8) void {
+            if (data.len == 0) return;
+
+            var remaining = data;
+
+            while (remaining.len > 0) {
+                const space_in_buffer = chunk_size - self.buffer_len;
+                const to_copy = @min(space_in_buffer, remaining.len);
+
+                // Copy data into buffer
+                @memcpy(self.buffer[self.buffer_len..][0..to_copy], remaining[0..to_copy]);
+                self.buffer_len += to_copy;
+                self.message_len += to_copy;
+                remaining = remaining[to_copy..];
+
+                // If buffer is full, process it
+                if (self.buffer_len == chunk_size) {
+                    if (self.first_chunk == null) {
+                        // First time buffer fills - initialize tree mode
+                        self.first_chunk = self.buffer;
+                        self.final_state = StateType.init(.{});
+
+                        // Absorb first chunk into final state
+                        self.final_state.?.update(&self.buffer);
+
+                        // Absorb padding (8 bytes: 0x03 followed by 7 zeros)
+                        const padding = [_]u8{ 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+                        self.final_state.?.update(&padding);
+                    } else {
+                        // Add chunk to pending buffer for SIMD batch processing
+                        @memcpy(self.pending_chunks[self.pending_count * chunk_size ..][0..chunk_size], &self.buffer);
+                        self.pending_count += 1;
+
+                        // Flush when we have enough chunks for optimal SIMD batch
+                        // Determine best batch size for this architecture
+                        const optimal_batch_size = comptime blk: {
+                            if (optimal_vector_len >= 8) break :blk 8;
+                            if (optimal_vector_len >= 4) break :blk 4;
+                            if (optimal_vector_len >= 2) break :blk 2;
+                            break :blk 1;
+                        };
+                        if (self.pending_count >= optimal_batch_size) {
+                            self.flushPendingChunks();
+                        }
+                    }
+                    self.buffer_len = 0;
+                }
+            }
+        }
+
+        /// Finalize the hash and produce output.
+        ///
+        /// Unlike traditional hash functions, the output can be of any length.
+        ///
+        /// When using as a regular hash function, use the recommended `digest_length` value (32 bytes for KT128, 64 bytes for KT256).
+        ///
+        /// After calling this method, the context should not be reused. However, the structure can be cloned before finalizing
+        /// to compute multiple hashes with the same prefix.
+        pub fn final(self: *Self, out: []u8) void {
+            const cv_size = Variant.cv_size;
+
+            // Calculate total length: message + customization + right_encode(customization.len)
+            const total_len = self.message_len + self.customization.len + self.custom_len_enc.len;
+
+            // Single chunk mode: total data fits in one chunk
+            if (total_len <= chunk_size) {
+                // Build the complete input: buffer + customization + encoded length
+                var single_chunk: [chunk_size]u8 = undefined;
+                @memcpy(single_chunk[0..self.buffer_len], self.buffer[0..self.buffer_len]);
+                @memcpy(single_chunk[self.buffer_len..][0..self.customization.len], self.customization);
+                @memcpy(single_chunk[self.buffer_len + self.customization.len ..][0..self.custom_len_enc.len], self.custom_len_enc.slice());
+
+                const view = MultiSliceView.init(single_chunk[0..total_len], &[_]u8{}, &[_]u8{});
+                singleChunkFn(&view, 0x07, out);
+                return;
+            }
+
+            // Flush any pending chunks with SIMD
+            self.flushPendingChunks();
+
+            // Build view over remaining data (buffer + customization + encoding)
+            const remaining_view = MultiSliceView.init(
+                self.buffer[0..self.buffer_len],
+                self.customization,
+                self.custom_len_enc.slice(),
+            );
+            const remaining_len = remaining_view.totalLen();
+
+            var final_leaves = self.num_leaves;
+            var leaf_start: usize = 0;
+
+            // Tree mode: initialize if not already done (lazy initialization)
+            if (self.final_state == null and remaining_len > 0) {
+                self.final_state = StateType.init(.{});
+
+                // Absorb first chunk (up to chunk_size bytes from remaining data)
+                const first_chunk_len = @min(chunk_size, remaining_len);
+                if (remaining_view.tryGetSlice(0, first_chunk_len)) |first_chunk| {
+                    // Data is contiguous, use it directly
+                    self.final_state.?.update(first_chunk);
+                } else {
+                    // Data spans boundaries, copy to buffer
+                    var first_chunk_buf: [chunk_size]u8 = undefined;
+                    remaining_view.copyRange(0, first_chunk_len, first_chunk_buf[0..first_chunk_len]);
+                    self.final_state.?.update(first_chunk_buf[0..first_chunk_len]);
+                }
+
+                // Absorb padding (8 bytes: 0x03 followed by 7 zeros)
+                const padding = [_]u8{ 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+                self.final_state.?.update(&padding);
+
+                // Process remaining data as leaves
+                leaf_start = first_chunk_len;
+            }
+
+            // Process all remaining data as leaves (starting from leaf_start)
+            var offset = leaf_start;
+            while (offset < remaining_len) {
+                const leaf_end = @min(offset + chunk_size, remaining_len);
+                const leaf_size = leaf_end - offset;
+
+                var cv_buffer: [64]u8 = undefined;
+                if (remaining_view.tryGetSlice(offset, leaf_end)) |leaf_data| {
+                    // Data is contiguous, use it directly
+                    const cv_slice = MultiSliceView.init(leaf_data, &[_]u8{}, &[_]u8{});
+                    Variant.turboShakeToBuffer(&cv_slice, 0x0B, cv_buffer[0..cv_size]);
+                } else {
+                    // Data spans boundaries, copy to buffer
+                    var leaf_buf: [chunk_size]u8 = undefined;
+                    remaining_view.copyRange(offset, leaf_end, leaf_buf[0..leaf_size]);
+                    const cv_slice = MultiSliceView.init(leaf_buf[0..leaf_size], &[_]u8{}, &[_]u8{});
+                    Variant.turboShakeToBuffer(&cv_slice, 0x0B, cv_buffer[0..cv_size]);
+                }
+                self.final_state.?.update(cv_buffer[0..cv_size]);
+                final_leaves += 1;
+                offset = leaf_end;
+            }
+
+            // Absorb right_encode(num_leaves) and terminator
+            const n_enc = rightEncode(final_leaves);
+            self.final_state.?.update(n_enc.slice());
+            const terminator = [_]u8{ 0xFF, 0xFF };
+            self.final_state.?.update(&terminator);
+
+            // Squeeze output
+            self.final_state.?.final(out);
+        }
+
+        /// Hash a message using sequential processing with SIMD acceleration.
+        ///
+        /// Parameters:
+        ///   - message: Input data to hash (any length)
+        ///   - out: Output buffer (any length, arbitrary output sizes supported, `digest_length` recommended for standard use)
+        ///   - options: Optional settings to include a secret key or a context separation string
+        pub fn hash(message: []const u8, out: []u8, options: Options) !void {
+            const custom = options.customization orelse &[_]u8{};
+
+            // Right-encode customization length
+            const custom_len_enc = rightEncode(custom.len);
+
+            // Create zero-copy multi-slice view (no concatenation)
+            const view = MultiSliceView.init(message, custom, custom_len_enc.slice());
+            const total_len = view.totalLen();
+
+            // Single chunk case - zero-copy absorption!
+            if (total_len <= chunk_size) {
+                singleChunkFn(&view, 0x07, out);
+                return;
+            }
+
+            // Tree mode - single-threaded SIMD processing
+            ktSingleThreaded(Variant, &view, total_len, out);
+        }
+    };
+}
+
+/// KangarooTwelve is a fast, secure cryptographic hash function that uses tree-hashing
+/// on top of TurboSHAKE. It is built on the Keccak permutation, the same primitive
+/// underlying SHA-3, which has undergone over 15 years of intensive cryptanalysis
+/// since the SHA-3 competition (2008-2012) and remains secure.
+///
+/// K12 uses Keccak-p[1600,12] with 12 rounds (half of SHA-3's 24 rounds), providing
+/// 128-bit security strength equivalent to AES-128 and SHAKE128. While this offers
+/// less conservative margin than SHA-3, current cryptanalysis reaches only 6 rounds,
+/// leaving a substantial security margin. This deliberate trade-off delivers
+/// significantly better performance while maintaining strong practical security.
+///
+/// Standardized as RFC 9861 after 8 years of public scrutiny. Supports arbitrary-length
+/// output and optional customization strings for domain separation.
+pub const KT128 = KTHash(KT128Variant, turboShake128MultiSliceToBuffer);
+
+/// KangarooTwelve is a fast, secure cryptographic hash function that uses tree-hashing
+/// on top of TurboSHAKE. It is built on the Keccak permutation, the same primitive
+/// underlying SHA-3, which has undergone over 15 years of intensive cryptanalysis
+/// since the SHA-3 competition (2008-2012) and remains secure.
+///
+/// KT256 provides 256-bit security strength and achieves NIST post-quantum security
+/// level 2 when using at least 256-bit outputs. Like KT128, it uses Keccak-p[1600,12]
+/// with 12 rounds, offering a deliberate trade-off between conservative margin and
+/// significantly better performance while maintaining strong practical security.
+///
+/// Use KT256 when you need extra conservative margins.
+/// For most applications, KT128 offers better performance with adequate security.
+pub const KT256 = KTHash(KT256Variant, turboShake256MultiSliceToBuffer);
+
+/// Helper: Generate pattern data where data[i] = (i % 251)
+fn generatePattern(allocator: Allocator, len: usize) ![]u8 {
+    const data = try allocator.alloc(u8, len);
+    for (data, 0..) |*byte, i| {
+        byte.* = @intCast(i % 251);
+    }
+    return data;
+}
+
+test "KT128: empty message, empty customization, 32 bytes" {
+    var output: [32]u8 = undefined;
+    try KT128.hash(&[_]u8{}, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "1AC2D450FC3B4205D19DA7BFCA1B37513C0803577AC7167F06FE2CE1F0EF39E5");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: empty message, empty customization, 64 bytes" {
+    var output: [64]u8 = undefined;
+    try KT128.hash(&[_]u8{}, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "1AC2D450FC3B4205D19DA7BFCA1B37513C0803577AC7167F06FE2CE1F0EF39E54269C056B8C82E48276038B6D292966CC07A3D4645272E31FF38508139EB0A71");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: empty message, empty customization, 10032 bytes (last 32)" {
+    const allocator = std.testing.allocator;
+    const output = try allocator.alloc(u8, 10032);
+    defer allocator.free(output);
+
+    try KT128.hash(&[_]u8{}, output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "E8DC563642F7228C84684C898405D3A834799158C079B12880277A1D28E2FF6D");
+    try std.testing.expectEqualSlices(u8, &expected, output[10000..]);
+}
+
+test "KT128: pattern message (1 byte), empty customization, 32 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 1);
+    defer allocator.free(message);
+
+    var output: [32]u8 = undefined;
+    try KT128.hash(message, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "2BDA92450E8B147F8A7CB629E784A058EFCA7CF7D8218E02D345DFAA65244A1F");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: pattern message (17 bytes), empty customization, 32 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 17);
+    defer allocator.free(message);
+
+    var output: [32]u8 = undefined;
+    try KT128.hash(message, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "6BF75FA2239198DB4772E36478F8E19B0F371205F6A9A93A273F51DF37122888");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: pattern message (289 bytes), empty customization, 32 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 289);
+    defer allocator.free(message);
+
+    var output: [32]u8 = undefined;
+    try KT128.hash(message, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "0C315EBCDEDBF61426DE7DCF8FB725D1E74675D7F5327A5067F367B108ECB67C");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: 0xFF message (1 byte), pattern customization (1 byte), 32 bytes" {
+    const allocator = std.testing.allocator;
+    const customization = try generatePattern(allocator, 1);
+    defer allocator.free(customization);
+
+    const message = [_]u8{0xFF};
+    var output: [32]u8 = undefined;
+    try KT128.hash(&message, &output, .{ .customization = customization });
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "A20B92B251E3D62443EC286E4B9B470A4E8315C156EEB24878B038ABE20650BE");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: pattern message (8191 bytes), empty customization, 32 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 8191);
+    defer allocator.free(message);
+
+    var output: [32]u8 = undefined;
+    try KT128.hash(message, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "1B577636F723643E990CC7D6A659837436FD6A103626600EB8301CD1DBE553D6");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: pattern message (8192 bytes), empty customization, 32 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 8192);
+    defer allocator.free(message);
+
+    var output: [32]u8 = undefined;
+    try KT128.hash(message, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "48F256F6772F9EDFB6A8B661EC92DC93B95EBD05A08A17B39AE3490870C926C3");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: empty message, empty customization, 64 bytes" {
+    var output: [64]u8 = undefined;
+    try KT256.hash(&[_]u8{}, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "B23D2E9CEA9F4904E02BEC06817FC10CE38CE8E93EF4C89E6537076AF8646404E3E8B68107B8833A5D30490AA33482353FD4ADC7148ECB782855003AAEBDE4A9");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: empty message, empty customization, 128 bytes" {
+    var output: [128]u8 = undefined;
+    try KT256.hash(&[_]u8{}, &output, .{});
+
+    var expected: [128]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "B23D2E9CEA9F4904E02BEC06817FC10CE38CE8E93EF4C89E6537076AF8646404E3E8B68107B8833A5D30490AA33482353FD4ADC7148ECB782855003AAEBDE4A9B0925319D8EA1E121A609821EC19EFEA89E6D08DAEE1662B69C840289F188BA860F55760B61F82114C030C97E5178449608CCD2CD2D919FC7829FF69931AC4D0");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: pattern message (1 byte), empty customization, 64 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 1);
+    defer allocator.free(message);
+
+    var output: [64]u8 = undefined;
+    try KT256.hash(message, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "0D005A194085360217128CF17F91E1F71314EFA5564539D444912E3437EFA17F82DB6F6FFE76E781EAA068BCE01F2BBF81EACB983D7230F2FB02834A21B1DDD0");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: pattern message (17 bytes), empty customization, 64 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 17);
+    defer allocator.free(message);
+
+    var output: [64]u8 = undefined;
+    try KT256.hash(message, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "1BA3C02B1FC514474F06C8979978A9056C8483F4A1B63D0DCCEFE3A28A2F323E1CDCCA40EBF006AC76EF0397152346837B1277D3E7FAA9C9653B19075098527B");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: pattern message (8191 bytes), empty customization, 64 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 8191);
+    defer allocator.free(message);
+
+    var output: [64]u8 = undefined;
+    try KT256.hash(message, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "3081434D93A4108D8D8A3305B89682CEBEDC7CA4EA8A3CE869FBB73CBE4A58EEF6F24DE38FFC170514C70E7AB2D01F03812616E863D769AFB3753193BA045B20");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: pattern message (8192 bytes), empty customization, 64 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 8192);
+    defer allocator.free(message);
+
+    var output: [64]u8 = undefined;
+    try KT256.hash(message, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "C6EE8E2AD3200C018AC87AAA031CDAC22121B412D07DC6E0DCCBB53423747E9A1C18834D99DF596CF0CF4B8DFAFB7BF02D139D0C9035725ADC1A01B7230A41FA");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: pattern message (8193 bytes), empty customization, 32 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 8193);
+    defer allocator.free(message);
+
+    var output: [32]u8 = undefined;
+    try KT128.hash(message, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "BB66FE72EAEA5179418D5295EE1344854D8AD7F3FA17EFCB467EC152341284CF");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: pattern message (16384 bytes), empty customization, 32 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 16384);
+    defer allocator.free(message);
+
+    var output: [32]u8 = undefined;
+    try KT128.hash(message, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "82778F7F7234C83352E76837B721FBDBB5270B88010D84FA5AB0B61EC8CE0956");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128: pattern message (16385 bytes), empty customization, 32 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 16385);
+    defer allocator.free(message);
+
+    var output: [32]u8 = undefined;
+    try KT128.hash(message, &output, .{});
+
+    var expected: [32]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "5F8D2B943922B451842B4E82740D02369E2D5F9F33C5123509A53B955FE177B2");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: pattern message (8193 bytes), empty customization, 64 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 8193);
+    defer allocator.free(message);
+
+    var output: [64]u8 = undefined;
+    try KT256.hash(message, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "65FF03335900E5197ACBD5F41B797F0E7E36AD4FF7D89C09FA6F28AE58D1E8BC2DF1779B86F988C3B13690172914EA172423B23EF4057255BB0836AB3A99836E");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: pattern message (16384 bytes), empty customization, 64 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 16384);
+    defer allocator.free(message);
+
+    var output: [64]u8 = undefined;
+    try KT256.hash(message, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "74604239A14847CB79069B4FF0E51070A93034C9AC4DFF4D45E0F2C5DA81D930DE6055C2134B4DF4E49F27D1B2C66E95491858B182A924BD0504DA5976BC516D");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT256: pattern message (16385 bytes), empty customization, 64 bytes" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 16385);
+    defer allocator.free(message);
+
+    var output: [64]u8 = undefined;
+    try KT256.hash(message, &output, .{});
+
+    var expected: [64]u8 = undefined;
+    _ = try std.fmt.hexToBytes(&expected, "C814F23132DADBFD55379F18CB988CB39B751F119322823FD982644A897485397B9F40EB11C6E416359B8AE695A5CE0FA79D1ADA1EEC745D82E0A5AB08A9F014");
+    try std.testing.expectEqualSlices(u8, &expected, &output);
+}
+
+test "KT128 incremental: empty message matches one-shot" {
+    var output_oneshot: [32]u8 = undefined;
+    var output_incremental: [32]u8 = undefined;
+
+    try KT128.hash(&[_]u8{}, &output_oneshot, .{});
+
+    var hasher = KT128.init(.{});
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT128 incremental: small message matches one-shot" {
+    const message = "Hello, KangarooTwelve!";
+
+    var output_oneshot: [32]u8 = undefined;
+    var output_incremental: [32]u8 = undefined;
+
+    try KT128.hash(message, &output_oneshot, .{});
+
+    var hasher = KT128.init(.{});
+    hasher.update(message);
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT128 incremental: multiple updates match single update" {
+    const part1 = "Hello, ";
+    const part2 = "Kangaroo";
+    const part3 = "Twelve!";
+
+    var output_single: [32]u8 = undefined;
+    var output_multi: [32]u8 = undefined;
+
+    // Single update
+    var hasher1 = KT128.init(.{});
+    hasher1.update(part1 ++ part2 ++ part3);
+    hasher1.final(&output_single);
+
+    // Multiple updates
+    var hasher2 = KT128.init(.{});
+    hasher2.update(part1);
+    hasher2.update(part2);
+    hasher2.update(part3);
+    hasher2.final(&output_multi);
+
+    try std.testing.expectEqualSlices(u8, &output_single, &output_multi);
+}
+
+test "KT128 incremental: exactly chunk_size matches one-shot" {
+    const allocator = std.testing.allocator;
+    const message = try allocator.alloc(u8, 8192);
+    defer allocator.free(message);
+    @memset(message, 0xAB);
+
+    var output_oneshot: [32]u8 = undefined;
+    var output_incremental: [32]u8 = undefined;
+
+    try KT128.hash(message, &output_oneshot, .{});
+
+    var hasher = KT128.init(.{});
+    hasher.update(message);
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT128 incremental: larger than chunk_size matches one-shot" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 16384);
+    defer allocator.free(message);
+
+    var output_oneshot: [32]u8 = undefined;
+    var output_incremental: [32]u8 = undefined;
+
+    try KT128.hash(message, &output_oneshot, .{});
+
+    var hasher = KT128.init(.{});
+    hasher.update(message);
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT128 incremental: with customization matches one-shot" {
+    const message = "Test message";
+    const customization = "my custom domain";
+
+    var output_oneshot: [32]u8 = undefined;
+    var output_incremental: [32]u8 = undefined;
+
+    try KT128.hash(message, &output_oneshot, .{ .customization = customization });
+
+    var hasher = KT128.init(.{ .customization = customization });
+    hasher.update(message);
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT128 incremental: large message with customization" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 20000);
+    defer allocator.free(message);
+    const customization = "test domain";
+
+    var output_oneshot: [48]u8 = undefined;
+    var output_incremental: [48]u8 = undefined;
+
+    try KT128.hash(message, &output_oneshot, .{ .customization = customization });
+
+    var hasher = KT128.init(.{ .customization = customization });
+    hasher.update(message);
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT128 incremental: streaming chunks matches one-shot" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 25000);
+    defer allocator.free(message);
+
+    var output_oneshot: [32]u8 = undefined;
+    var output_incremental: [32]u8 = undefined;
+
+    try KT128.hash(message, &output_oneshot, .{});
+
+    var hasher = KT128.init(.{});
+
+    // Feed in 1KB chunks
+    var offset: usize = 0;
+    while (offset < message.len) {
+        const chunk_size_local = @min(1024, message.len - offset);
+        hasher.update(message[offset..][0..chunk_size_local]);
+        offset += chunk_size_local;
+    }
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT256 incremental: empty message matches one-shot" {
+    var output_oneshot: [64]u8 = undefined;
+    var output_incremental: [64]u8 = undefined;
+
+    try KT256.hash(&[_]u8{}, &output_oneshot, .{});
+
+    var hasher = KT256.init(.{});
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT256 incremental: small message matches one-shot" {
+    const message = "Hello, KangarooTwelve with 256-bit security!";
+
+    var output_oneshot: [64]u8 = undefined;
+    var output_incremental: [64]u8 = undefined;
+
+    try KT256.hash(message, &output_oneshot, .{});
+
+    var hasher = KT256.init(.{});
+    hasher.update(message);
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT256 incremental: large message matches one-shot" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 30000);
+    defer allocator.free(message);
+
+    var output_oneshot: [64]u8 = undefined;
+    var output_incremental: [64]u8 = undefined;
+
+    try KT256.hash(message, &output_oneshot, .{});
+
+    var hasher = KT256.init(.{});
+    hasher.update(message);
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT256 incremental: with customization matches one-shot" {
+    const allocator = std.testing.allocator;
+    const message = try generatePattern(allocator, 15000);
+    defer allocator.free(message);
+    const customization = "KT256 custom domain";
+
+    var output_oneshot: [80]u8 = undefined;
+    var output_incremental: [80]u8 = undefined;
+
+    try KT256.hash(message, &output_oneshot, .{ .customization = customization });
+
+    var hasher = KT256.init(.{ .customization = customization });
+    hasher.update(message);
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT128 incremental: random small message with random chunk sizes" {
+    const allocator = std.testing.allocator;
+
+    var prng = std.Random.DefaultPrng.init(std.testing.random_seed);
+    const random = prng.random();
+
+    const test_sizes = [_]usize{ 100, 500, 2000, 5000, 10000 };
+
+    for (test_sizes) |total_size| {
+        const message = try allocator.alloc(u8, total_size);
+        defer allocator.free(message);
+        random.bytes(message);
+
+        var output_oneshot: [32]u8 = undefined;
+        var output_incremental: [32]u8 = undefined;
+
+        try KT128.hash(message, &output_oneshot, .{});
+
+        var hasher = KT128.init(.{});
+        var offset: usize = 0;
+
+        while (offset < message.len) {
+            const remaining = message.len - offset;
+            const max_chunk = @min(1000, remaining);
+            const chunk_size_local = if (max_chunk == 1) 1 else random.intRangeAtMost(usize, 1, max_chunk);
+
+            hasher.update(message[offset..][0..chunk_size_local]);
+            offset += chunk_size_local;
+        }
+        hasher.final(&output_incremental);
+
+        try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+    }
+}
+
+test "KT128 incremental: random large message (1MB) with random chunk sizes" {
+    const allocator = std.testing.allocator;
+
+    var prng = std.Random.DefaultPrng.init(std.testing.random_seed);
+    const random = prng.random();
+
+    const total_size: usize = 1024 * 1024; // 1 MB
+    const message = try allocator.alloc(u8, total_size);
+    defer allocator.free(message);
+    random.bytes(message);
+
+    var output_oneshot: [32]u8 = undefined;
+    var output_incremental: [32]u8 = undefined;
+
+    try KT128.hash(message, &output_oneshot, .{});
+
+    var hasher = KT128.init(.{});
+    var offset: usize = 0;
+
+    while (offset < message.len) {
+        const remaining = message.len - offset;
+        const max_chunk = @min(10000, remaining);
+        const chunk_size_local = if (max_chunk == 1) 1 else random.intRangeAtMost(usize, 1, max_chunk);
+
+        hasher.update(message[offset..][0..chunk_size_local]);
+        offset += chunk_size_local;
+    }
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT256 incremental: random small message with random chunk sizes" {
+    const allocator = std.testing.allocator;
+
+    var prng = std.Random.DefaultPrng.init(std.testing.random_seed);
+    const random = prng.random();
+
+    const test_sizes = [_]usize{ 100, 500, 2000, 5000, 10000 };
+
+    for (test_sizes) |total_size| {
+        // Generate random message
+        const message = try allocator.alloc(u8, total_size);
+        defer allocator.free(message);
+        random.bytes(message);
+
+        var output_oneshot: [64]u8 = undefined;
+        var output_incremental: [64]u8 = undefined;
+
+        try KT256.hash(message, &output_oneshot, .{});
+
+        var hasher = KT256.init(.{});
+        var offset: usize = 0;
+
+        while (offset < message.len) {
+            const remaining = message.len - offset;
+            const max_chunk = @min(1000, remaining);
+            const chunk_size_local = if (max_chunk == 1) 1 else random.intRangeAtMost(usize, 1, max_chunk);
+
+            hasher.update(message[offset..][0..chunk_size_local]);
+            offset += chunk_size_local;
+        }
+        hasher.final(&output_incremental);
+
+        try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+    }
+}
+
+test "KT256 incremental: random large message (1MB) with random chunk sizes" {
+    const allocator = std.testing.allocator;
+
+    var prng = std.Random.DefaultPrng.init(std.testing.random_seed);
+    const random = prng.random();
+
+    const total_size: usize = 1024 * 1024; // 1 MB
+    const message = try allocator.alloc(u8, total_size);
+    defer allocator.free(message);
+    random.bytes(message);
+
+    var output_oneshot: [64]u8 = undefined;
+    var output_incremental: [64]u8 = undefined;
+
+    try KT256.hash(message, &output_oneshot, .{});
+
+    var hasher = KT256.init(.{});
+    var offset: usize = 0;
+
+    while (offset < message.len) {
+        const remaining = message.len - offset;
+        const max_chunk = @min(10000, remaining);
+        const chunk_size_local = if (max_chunk == 1) 1 else random.intRangeAtMost(usize, 1, max_chunk);
+
+        hasher.update(message[offset..][0..chunk_size_local]);
+        offset += chunk_size_local;
+    }
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
+
+test "KT128 incremental: random message with customization and random chunks" {
+    const allocator = std.testing.allocator;
+
+    var prng = std.Random.DefaultPrng.init(std.testing.random_seed);
+    const random = prng.random();
+
+    const total_size: usize = 50000;
+    const message = try allocator.alloc(u8, total_size);
+    defer allocator.free(message);
+    random.bytes(message);
+
+    const customization = "random test domain";
+
+    var output_oneshot: [48]u8 = undefined;
+    var output_incremental: [48]u8 = undefined;
+
+    try KT128.hash(message, &output_oneshot, .{ .customization = customization });
+
+    var hasher = KT128.init(.{ .customization = customization });
+    var offset: usize = 0;
+
+    while (offset < message.len) {
+        const remaining = message.len - offset;
+        const max_chunk = @min(5000, remaining);
+        const chunk_size_local = if (max_chunk == 1) 1 else random.intRangeAtMost(usize, 1, max_chunk);
+
+        hasher.update(message[offset..][0..chunk_size_local]);
+        offset += chunk_size_local;
+    }
+    hasher.final(&output_incremental);
+
+    try std.testing.expectEqualSlices(u8, &output_oneshot, &output_incremental);
+}
diff --git a/lib/std/crypto/sha3.zig b/lib/std/crypto/sha3.zig
index 332276ded6..9173beb2cf 100644
--- a/lib/std/crypto/sha3.zig
+++ b/lib/std/crypto/sha3.zig
@@ -4,6 +4,8 @@ const assert = std.debug.assert;
 const math = std.math;
 const mem = std.mem;
 
+const kangarootwelve = @import("kangarootwelve.zig");
+
 const KeccakState = std.crypto.core.keccak.State;
 
 pub const Sha3_224 = Keccak(1600, 224, 0x06, 24);
@@ -26,6 +28,9 @@ pub const KMac256 = KMac(256);
 pub const TupleHash128 = TupleHash(128);
 pub const TupleHash256 = TupleHash(256);
 
+pub const KT128 = kangarootwelve.KT128;
+pub const KT256 = kangarootwelve.KT256;
+
 /// TurboSHAKE128 is a XOF (a secure hash function with a variable output length), with a 128 bit security level.
 /// It is based on the same permutation as SHA3 and SHAKE128, but which much higher performance.
 /// The delimiter is 0x1f by default, but can be changed for context-separation.
@@ -481,6 +486,10 @@ pub const NistLengthEncoding = enum {
 
 const htest = @import("test.zig");
 
+test {
+    _ = kangarootwelve;
+}
+
 test "sha3-224 single" {
     try htest.assertEqualHash(Sha3_224, "6b4e03423667dbb73b6e15454f0eb1abd4597f9a1b078e3f5b5a6bc7", "");
     try htest.assertEqualHash(Sha3_224, "e642824c3f8cf24ad09234ee7d3c766fc9a3a5168d0c94ad73b46fdf", "abc");