diff --git a/kupyna512/Cargo.toml b/kupyna512/Cargo.toml
new file mode 100644
index 00000000..ba6fb9e6
--- /dev/null
+++ b/kupyna512/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "kupyna512"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/kupyna512/src/lib.rs b/kupyna512/src/lib.rs
new file mode 100644
index 00000000..da4df891
--- /dev/null
+++ b/kupyna512/src/lib.rs
@@ -0,0 +1,101 @@
+#[cfg(test)]
+mod tests;
+mod sub_units;
+
+const STATE_SIZE: usize = 1024;
+const HASH_SIZE: usize = 512;
+
+const MAX_MESSAGE_LENGTH: usize = 18446744073709551615;
+
+fn pad_message(message: &[u8], msg_len_bits: usize, state_size: usize) -> Vec<u8> {
+    let round_msg_len = message.len() * 8;
+    let d =
+        ((-((round_msg_len + 97) as isize) % (state_size as isize)) + state_size as isize) as usize;
+
+    // Calculate the length of padding to be added
+    let pad_len = d / 8;
+
+    // We set the padded message size upfront to reduce allocations
+    let padded_len = (msg_len_bits + 7) / 8 + pad_len + 13;
+    let mut padded_message = vec![0x00; padded_len];
+
+    // Copy n bits from the input message
+    let full_bytes = msg_len_bits / 8;
+    let remaining_bits = msg_len_bits % 8;
+
+    padded_message[..full_bytes].copy_from_slice(&message[..full_bytes]);
+
+    if remaining_bits > 0 {
+        let last_byte = message[full_bytes];
+        padded_message[full_bytes] = last_byte & ((1 << remaining_bits) - 1);
+    }
+
+    // Set the n+1'th bit to high
+    padded_message[msg_len_bits / 8] |= 1 << (7 - (msg_len_bits % 8));
+
+    // Convert the length to a byte array and copy it into the padded message
+    let n_bytes = (msg_len_bits as u128).to_le_bytes(); // message length in little-endian
+    padded_message[padded_len - 12..].copy_from_slice(&n_bytes[0..12]);
+
+    padded_message
+}
+
+fn divide_into_blocks(padded_message: &[u8], state_size: usize) -> Vec<&[u8]> {
+    padded_message.chunks(state_size / 8).collect()
+}
+
+fn truncate(block: &[u8], n: usize) -> Vec<u8> {
+    let bytes_to_keep = n / 8;
+    let start_index = if block.len() > bytes_to_keep {
+        block.len() - bytes_to_keep
+    } else {
+        0
+    };
+    block[start_index..].to_vec()
+}
+
+pub fn hash(message: Vec<u8>, length: Option<usize>) -> Result<Vec<u8>, &'static str> {
+    let mut message = message;
+    let message_length: usize;
+    if let Some(len) = length {
+        if len > MAX_MESSAGE_LENGTH {
+            return Err("Message is too long");
+        }
+        if len > message.len() * 8 {
+            return Err("Message length is less than the provided length");
+        }
+
+        let mut trimmed_message = message[..(len/8)].to_vec();
+
+        if len % 8 != 0 {
+            let extra_byte = message[len/8];
+            let extra_bits = len % 8;
+            let mask = 0xFF << (8 - extra_bits);
+            trimmed_message.push(extra_byte & mask);
+        }
+
+        message = trimmed_message;
+        message_length = len;
+
+    } else {
+        if message.len() * 8 > MAX_MESSAGE_LENGTH {
+            return Err("Message is too long");
+        }
+        message_length = message.len() * 8;
+    }
+
+    let padded_message = pad_message(&message, message_length, STATE_SIZE);
+
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE);
+
+    let mut init_vector: Vec<u8> = vec![0; STATE_SIZE/8];
+    init_vector[0] = 0x80; // set the first bit of this init vector to high
+
+
+    let fin_vector = sub_units::plant(blocks, &init_vector);
+
+    let hash = truncate(&fin_vector, HASH_SIZE);
+
+    Ok(hash)
+}
+
diff --git a/kupyna512/src/main.rs b/kupyna512/src/main.rs
new file mode 100644
index 00000000..552e0bfd
--- /dev/null
+++ b/kupyna512/src/main.rs
@@ -0,0 +1,10 @@
+use kupyna512;
+
+fn main() {
+    let message = b"Hello, World!".to_vec();
+    let _message_length = 0;
+
+    let hash_code = kupyna512::hash(message, None).unwrap();
+
+    println!("{:02X?}", hash_code);
+}
\ No newline at end of file
diff --git a/kupyna512/src/sub_units/mod.rs b/kupyna512/src/sub_units/mod.rs
new file mode 100644
index 00000000..beeae736
--- /dev/null
+++ b/kupyna512/src/sub_units/mod.rs
@@ -0,0 +1,43 @@
+mod t_xor_plus;
+
+use t_xor_plus::{t_xor_l, t_plus_l};
+
+const ROUNDS: usize = 14;
+
+fn xor_bytes(a: &[u8], b: &[u8]) -> Vec<u8> {
+    a.iter().zip(b.iter()).map(|(x, y)| x ^ y).collect()
+}
+
+fn silo(message_block: &[u8], prev_vector: &[u8]) -> Vec<u8> {
+
+    let m_xor_p = xor_bytes(message_block, prev_vector);
+
+    let t_xor_mp = t_xor_l(&m_xor_p, ROUNDS);
+
+    let t_plus_m = t_plus_l(&message_block, ROUNDS);
+
+    let return_vector = xor_bytes(&(xor_bytes(&t_xor_mp, &t_plus_m)), prev_vector);
+
+    return_vector
+
+}
+
+pub(crate) fn plant(message_blocks: Vec<&[u8]>, init_vector: &[u8]) -> Vec<u8> {
+
+    let mut last_vector = init_vector.to_vec();
+
+    for block in message_blocks {
+        last_vector = silo(block, &last_vector);
+    }
+
+    let last_vector = finalize(&last_vector);
+
+    last_vector
+}
+
+fn finalize(ult_processed_block: &[u8]) -> Vec<u8> {
+    let t_xor_ult_processed_block = t_xor_l(ult_processed_block, ROUNDS);
+    let final_state = xor_bytes(ult_processed_block, &t_xor_ult_processed_block);
+    final_state
+}
+
diff --git a/kupyna512/src/sub_units/t_xor_plus/mod.rs b/kupyna512/src/sub_units/t_xor_plus/mod.rs
new file mode 100644
index 00000000..bf385edf
--- /dev/null
+++ b/kupyna512/src/sub_units/t_xor_plus/mod.rs
@@ -0,0 +1,162 @@
+#[cfg(test)]
+mod tests;
+
+mod tables;
+
+const ROWS: usize = 16;
+const COLS: usize = 8; // For 512-bit state, adjust if needed
+
+const BITS_IN_BYTE: u8 = 8;
+const REDUCTION_POLYNOMIAL: u16 = 0x011d;
+
+type Matrix = [[u8; COLS]; ROWS];
+
+use tables::{MDS_MATRIX, SBOXES};
+
+
+pub(crate) fn block_to_matrix(block: &[u8]) -> Matrix {
+    let mut matrix = [[0u8; COLS]; ROWS];
+    for i in 0..ROWS {
+        for j in 0..COLS {
+            matrix[i][j] = block[i * COLS + j];
+        }
+    }
+    matrix
+}
+
+fn matrix_to_block(matrix: Matrix) -> Vec<u8> {
+    let mut block = vec![0u8; ROWS * COLS];
+    for i in 0..ROWS {
+        for j in 0..COLS {
+            block[i * COLS + j] = matrix[i][j];
+        }
+    }
+    block
+}
+
+pub(crate) fn add_constant_xor(mut state: Matrix, round: usize) -> Matrix {
+    for j in 0..ROWS {
+        let constant = ((j * 0x10) ^ round) as u8;
+        state[j][0] ^= constant;
+    }
+    state
+}
+
+pub(crate) fn add_constant_plus(mut state: Matrix, round: usize) -> Matrix {
+    let state_ptr = state.as_mut_ptr() as *mut u64;
+
+    for j in 0..ROWS {
+        // dbg!("{}",j);
+        unsafe {
+            *state_ptr.add(j) = state_ptr.add(j).read().wrapping_add(
+                0x00F0F0F0F0F0F0F3u64 ^ (((((ROWS - j - 1) * 0x10) ^ round) as u64) << 56),
+            );
+        }
+    }
+
+    state
+}
+
+pub(crate) fn s_box_layer(mut state: Matrix) -> Matrix {
+    for i in 0..COLS {
+        for j in 0..ROWS {
+            state[j][i] = SBOXES[i % 4][state[j][i] as usize];
+        }
+    }
+    state
+}
+
+pub(crate) fn rotate_rows(mut state: Matrix) -> Matrix {
+    let mut temp = [0u8; ROWS];
+    let mut shift: i32 = -1;
+    for i in 0..COLS {
+        if (i == COLS - 1) && true {
+            shift = 11;
+        } else {
+            shift += 1;
+        }
+        for col in 0..ROWS {
+            temp[(col + shift as usize) % ROWS] = state[col][i];
+        }
+        for col in 0..ROWS {
+            state[col][i] = temp[col];
+        }
+    }
+    state
+}
+
+fn multiply_gf(mut x: u8, mut y: u8) -> u8 {
+    let mut r = 0u8;
+
+    for _ in 0..BITS_IN_BYTE {
+        if y & 1 == 1 {
+            r ^= x;
+        }
+        let hbit = (x & 0x80) >> 7;
+        x <<= 1;
+        if hbit == 1 {
+            x ^= REDUCTION_POLYNOMIAL as u8;
+        }
+        y >>= 1;
+    }
+
+    r
+}
+
+pub(crate) fn mix_columns(state: Matrix) -> Matrix {
+    let mut result = [[0u8; COLS]; ROWS];
+
+    for col in 0..ROWS {
+        for row in (0..COLS).rev() {
+            let mut product = 0u8;
+            for b in (0..COLS).rev() {
+                product ^= multiply_gf(state[col][b], MDS_MATRIX[row][b]);
+            }
+            result[col][row] = product;
+        }
+    }
+
+    result
+}
+
+/// Placeholder for the T⊕l transformation.
+///
+/// # Arguments
+///
+/// * `block` - A byte slice representing the block to be transformed.
+/// * `_rounds` - The number of rounds to perform.
+///
+/// # Returns
+///
+/// * A `Vec<u8>` containing the transformed block.
+pub fn t_xor_l(block: &[u8], rounds: usize) -> Vec<u8> {
+    let mut state = block_to_matrix(block);
+    for nu in 0..rounds {
+        state = add_constant_xor(state, nu);
+        state = s_box_layer(state);
+        state = rotate_rows(state);
+        state = mix_columns(state);
+    }
+    matrix_to_block(state)
+}
+
+/// Placeholder for the T+l transformation.
+///
+/// # Arguments
+///
+/// * `block` - A byte slice representing the block to be transformed.
+/// * `_rounds` - The number of rounds to perform.
+///
+/// # Returns
+///
+/// * A `Vec<u8>` containing the transformed block.
+pub fn t_plus_l(block: &[u8], rounds: usize) -> Vec<u8> {
+    let mut state = block_to_matrix(block);
+    for nu in 0..rounds {
+        state = add_constant_plus(state, nu);
+        state = s_box_layer(state);
+        state = rotate_rows(state);
+        state = mix_columns(state);
+    }
+    matrix_to_block(state)
+}
\ No newline at end of file
diff --git a/kupyna512/src/sub_units/t_xor_plus/tables.rs b/kupyna512/src/sub_units/t_xor_plus/tables.rs
new file mode 100644
index 00000000..75dfd9db
--- /dev/null
+++ b/kupyna512/src/sub_units/t_xor_plus/tables.rs
@@ -0,0 +1,97 @@
+pub const MDS_MATRIX: [[u8; 8]; 8] = [
+    [0x01, 0x01, 0x05, 0x01, 0x08, 0x06, 0x07, 0x04],
+    [0x04, 0x01, 0x01, 0x05, 0x01, 0x08, 0x06, 0x07],
+    [0x07, 0x04, 0x01, 0x01, 0x05, 0x01, 0x08, 0x06],
+    [0x06, 0x07, 0x04, 0x01, 0x01, 0x05, 0x01, 0x08],
+    [0x08, 0x06, 0x07, 0x04, 0x01, 0x01, 0x05, 0x01],
+    [0x01, 0x08, 0x06, 0x07, 0x04, 0x01, 0x01, 0x05],
+    [0x05, 0x01, 0x08, 0x06, 0x07, 0x04, 0x01, 0x01],
+    [0x01, 0x05, 0x01, 0x08, 0x06, 0x07, 0x04, 0x01],
+];
+
+pub const SBOXES: [[u8; 256]; 4] = [
+    // The first subarray goes here
+    [
+        0xa8, 0x43, 0x5f, 0x06, 0x6b, 0x75, 0x6c, 0x59, 0x71, 0xdf, 0x87, 0x95, 0x17, 0xf0, 0xd8,
+        0x09, 0x6d, 0xf3, 0x1d, 0xcb, 0xc9, 0x4d, 0x2c, 0xaf, 0x79, 0xe0, 0x97, 0xfd, 0x6f, 0x4b,
+        0x45, 0x39, 0x3e, 0xdd, 0xa3, 0x4f, 0xb4, 0xb6, 0x9a, 0x0e, 0x1f, 0xbf, 0x15, 0xe1, 0x49,
+        0xd2, 0x93, 0xc6, 0x92, 0x72, 0x9e, 0x61, 0xd1, 0x63, 0xfa, 0xee, 0xf4, 0x19, 0xd5, 0xad,
+        0x58, 0xa4, 0xbb, 0xa1, 0xdc, 0xf2, 0x83, 0x37, 0x42, 0xe4, 0x7a, 0x32, 0x9c, 0xcc, 0xab,
+        0x4a, 0x8f, 0x6e, 0x04, 0x27, 0x2e, 0xe7, 0xe2, 0x5a, 0x96, 0x16, 0x23, 0x2b, 0xc2, 0x65,
+        0x66, 0x0f, 0xbc, 0xa9, 0x47, 0x41, 0x34, 0x48, 0xfc, 0xb7, 0x6a, 0x88, 0xa5, 0x53, 0x86,
+        0xf9, 0x5b, 0xdb, 0x38, 0x7b, 0xc3, 0x1e, 0x22, 0x33, 0x24, 0x28, 0x36, 0xc7, 0xb2, 0x3b,
+        0x8e, 0x77, 0xba, 0xf5, 0x14, 0x9f, 0x08, 0x55, 0x9b, 0x4c, 0xfe, 0x60, 0x5c, 0xda, 0x18,
+        0x46, 0xcd, 0x7d, 0x21, 0xb0, 0x3f, 0x1b, 0x89, 0xff, 0xeb, 0x84, 0x69, 0x3a, 0x9d, 0xd7,
+        0xd3, 0x70, 0x67, 0x40, 0xb5, 0xde, 0x5d, 0x30, 0x91, 0xb1, 0x78, 0x11, 0x01, 0xe5, 0x00,
+        0x68, 0x98, 0xa0, 0xc5, 0x02, 0xa6, 0x74, 0x2d, 0x0b, 0xa2, 0x76, 0xb3, 0xbe, 0xce, 0xbd,
+        0xae, 0xe9, 0x8a, 0x31, 0x1c, 0xec, 0xf1, 0x99, 0x94, 0xaa, 0xf6, 0x26, 0x2f, 0xef, 0xe8,
+        0x8c, 0x35, 0x03, 0xd4, 0x7f, 0xfb, 0x05, 0xc1, 0x5e, 0x90, 0x20, 0x3d, 0x82, 0xf7, 0xea,
+        0x0a, 0x0d, 0x7e, 0xf8, 0x50, 0x1a, 0xc4, 0x07, 0x57, 0xb8, 0x3c, 0x62, 0xe3, 0xc8, 0xac,
+        0x52, 0x64, 0x10, 0xd0, 0xd9, 0x13, 0x0c, 0x12, 0x29, 0x51, 0xb9, 0xcf, 0xd6, 0x73, 0x8d,
+        0x81, 0x54, 0xc0, 0xed, 0x4e, 0x44, 0xa7, 0x2a, 0x85, 0x25, 0xe6, 0xca, 0x7c, 0x8b, 0x56,
+        0x80,
+    ],
+    // The second subarray goes here
+    [
+        0xce, 0xbb, 0xeb, 0x92, 0xea, 0xcb, 0x13, 0xc1, 0xe9, 0x3a, 0xd6, 0xb2, 0xd2, 0x90, 0x17,
+        0xf8, 0x42, 0x15, 0x56, 0xb4, 0x65, 0x1c, 0x88, 0x43, 0xc5, 0x5c, 0x36, 0xba, 0xf5, 0x57,
+        0x67, 0x8d, 0x31, 0xf6, 0x64, 0x58, 0x9e, 0xf4, 0x22, 0xaa, 0x75, 0x0f, 0x02, 0xb1, 0xdf,
+        0x6d, 0x73, 0x4d, 0x7c, 0x26, 0x2e, 0xf7, 0x08, 0x5d, 0x44, 0x3e, 0x9f, 0x14, 0xc8, 0xae,
+        0x54, 0x10, 0xd8, 0xbc, 0x1a, 0x6b, 0x69, 0xf3, 0xbd, 0x33, 0xab, 0xfa, 0xd1, 0x9b, 0x68,
+        0x4e, 0x16, 0x95, 0x91, 0xee, 0x4c, 0x63, 0x8e, 0x5b, 0xcc, 0x3c, 0x19, 0xa1, 0x81, 0x49,
+        0x7b, 0xd9, 0x6f, 0x37, 0x60, 0xca, 0xe7, 0x2b, 0x48, 0xfd, 0x96, 0x45, 0xfc, 0x41, 0x12,
+        0x0d, 0x79, 0xe5, 0x89, 0x8c, 0xe3, 0x20, 0x30, 0xdc, 0xb7, 0x6c, 0x4a, 0xb5, 0x3f, 0x97,
+        0xd4, 0x62, 0x2d, 0x06, 0xa4, 0xa5, 0x83, 0x5f, 0x2a, 0xda, 0xc9, 0x00, 0x7e, 0xa2, 0x55,
+        0xbf, 0x11, 0xd5, 0x9c, 0xcf, 0x0e, 0x0a, 0x3d, 0x51, 0x7d, 0x93, 0x1b, 0xfe, 0xc4, 0x47,
+        0x09, 0x86, 0x0b, 0x8f, 0x9d, 0x6a, 0x07, 0xb9, 0xb0, 0x98, 0x18, 0x32, 0x71, 0x4b, 0xef,
+        0x3b, 0x70, 0xa0, 0xe4, 0x40, 0xff, 0xc3, 0xa9, 0xe6, 0x78, 0xf9, 0x8b, 0x46, 0x80, 0x1e,
+        0x38, 0xe1, 0xb8, 0xa8, 0xe0, 0x0c, 0x23, 0x76, 0x1d, 0x25, 0x24, 0x05, 0xf1, 0x6e, 0x94,
+        0x28, 0x9a, 0x84, 0xe8, 0xa3, 0x4f, 0x77, 0xd3, 0x85, 0xe2, 0x52, 0xf2, 0x82, 0x50, 0x7a,
+        0x2f, 0x74, 0x53, 0xb3, 0x61, 0xaf, 0x39, 0x35, 0xde, 0xcd, 0x1f, 0x99, 0xac, 0xad, 0x72,
+        0x2c, 0xdd, 0xd0, 0x87, 0xbe, 0x5e, 0xa6, 0xec, 0x04, 0xc6, 0x03, 0x34, 0xfb, 0xdb, 0x59,
+        0xb6, 0xc2, 0x01, 0xf0, 0x5a, 0xed, 0xa7, 0x66, 0x21, 0x7f, 0x8a, 0x27, 0xc7, 0xc0, 0x29,
+        0xd7,
+    ],
+    // The third subarray goes here
+    [
+        0x93, 0xd9, 0x9a, 0xb5, 0x98, 0x22, 0x45, 0xfc, 0xba, 0x6a, 0xdf, 0x02, 0x9f, 0xdc, 0x51,
+        0x59, 0x4a, 0x17, 0x2b, 0xc2, 0x94, 0xf4, 0xbb, 0xa3, 0x62, 0xe4, 0x71, 0xd4, 0xcd, 0x70,
+        0x16, 0xe1, 0x49, 0x3c, 0xc0, 0xd8, 0x5c, 0x9b, 0xad, 0x85, 0x53, 0xa1, 0x7a, 0xc8, 0x2d,
+        0xe0, 0xd1, 0x72, 0xa6, 0x2c, 0xc4, 0xe3, 0x76, 0x78, 0xb7, 0xb4, 0x09, 0x3b, 0x0e, 0x41,
+        0x4c, 0xde, 0xb2, 0x90, 0x25, 0xa5, 0xd7, 0x03, 0x11, 0x00, 0xc3, 0x2e, 0x92, 0xef, 0x4e,
+        0x12, 0x9d, 0x7d, 0xcb, 0x35, 0x10, 0xd5, 0x4f, 0x9e, 0x4d, 0xa9, 0x55, 0xc6, 0xd0, 0x7b,
+        0x18, 0x97, 0xd3, 0x36, 0xe6, 0x48, 0x56, 0x81, 0x8f, 0x77, 0xcc, 0x9c, 0xb9, 0xe2, 0xac,
+        0xb8, 0x2f, 0x15, 0xa4, 0x7c, 0xda, 0x38, 0x1e, 0x0b, 0x05, 0xd6, 0x14, 0x6e, 0x6c, 0x7e,
+        0x66, 0xfd, 0xb1, 0xe5, 0x60, 0xaf, 0x5e, 0x33, 0x87, 0xc9, 0xf0, 0x5d, 0x6d, 0x3f, 0x88,
+        0x8d, 0xc7, 0xf7, 0x1d, 0xe9, 0xec, 0xed, 0x80, 0x29, 0x27, 0xcf, 0x99, 0xa8, 0x50, 0x0f,
+        0x37, 0x24, 0x28, 0x30, 0x95, 0xd2, 0x3e, 0x5b, 0x40, 0x83, 0xb3, 0x69, 0x57, 0x1f, 0x07,
+        0x1c, 0x8a, 0xbc, 0x20, 0xeb, 0xce, 0x8e, 0xab, 0xee, 0x31, 0xa2, 0x73, 0xf9, 0xca, 0x3a,
+        0x1a, 0xfb, 0x0d, 0xc1, 0xfe, 0xfa, 0xf2, 0x6f, 0xbd, 0x96, 0xdd, 0x43, 0x52, 0xb6, 0x08,
+        0xf3, 0xae, 0xbe, 0x19, 0x89, 0x32, 0x26, 0xb0, 0xea, 0x4b, 0x64, 0x84, 0x82, 0x6b, 0xf5,
+        0x79, 0xbf, 0x01, 0x5f, 0x75, 0x63, 0x1b, 0x23, 0x3d, 0x68, 0x2a, 0x65, 0xe8, 0x91, 0xf6,
+        0xff, 0x13, 0x58, 0xf1, 0x47, 0x0a, 0x7f, 0xc5, 0xa7, 0xe7, 0x61, 0x5a, 0x06, 0x46, 0x44,
+        0x42, 0x04, 0xa0, 0xdb, 0x39, 0x86, 0x54, 0xaa, 0x8c, 0x34, 0x21, 0x8b, 0xf8, 0x0c, 0x74,
+        0x67,
+    ],
+    // The fourth subarray goes here
+    [
+        0x68, 0x8d, 0xca, 0x4d, 0x73, 0x4b, 0x4e, 0x2a, 0xd4, 0x52, 0x26, 0xb3, 0x54, 0x1e, 0x19,
+        0x1f, 0x22, 0x03, 0x46, 0x3d, 0x2d, 0x4a, 0x53, 0x83, 0x13, 0x8a, 0xb7, 0xd5, 0x25, 0x79,
+        0xf5, 0xbd, 0x58, 0x2f, 0x0d, 0x02, 0xed, 0x51, 0x9e, 0x11, 0xf2, 0x3e, 0x55, 0x5e, 0xd1,
+        0x16, 0x3c, 0x66, 0x70, 0x5d, 0xf3, 0x45, 0x40, 0xcc, 0xe8, 0x94, 0x56, 0x08, 0xce, 0x1a,
+        0x3a, 0xd2, 0xe1, 0xdf, 0xb5, 0x38, 0x6e, 0x0e, 0xe5, 0xf4, 0xf9, 0x86, 0xe9, 0x4f, 0xd6,
+        0x85, 0x23, 0xcf, 0x32, 0x99, 0x31, 0x14, 0xae, 0xee, 0xc8, 0x48, 0xd3, 0x30, 0xa1, 0x92,
+        0x41, 0xb1, 0x18, 0xc4, 0x2c, 0x71, 0x72, 0x44, 0x15, 0xfd, 0x37, 0xbe, 0x5f, 0xaa, 0x9b,
+        0x88, 0xd8, 0xab, 0x89, 0x9c, 0xfa, 0x60, 0xea, 0xbc, 0x62, 0x0c, 0x24, 0xa6, 0xa8, 0xec,
+        0x67, 0x20, 0xdb, 0x7c, 0x28, 0xdd, 0xac, 0x5b, 0x34, 0x7e, 0x10, 0xf1, 0x7b, 0x8f, 0x63,
+        0xa0, 0x05, 0x9a, 0x43, 0x77, 0x21, 0xbf, 0x27, 0x09, 0xc3, 0x9f, 0xb6, 0xd7, 0x29, 0xc2,
+        0xeb, 0xc0, 0xa4, 0x8b, 0x8c, 0x1d, 0xfb, 0xff, 0xc1, 0xb2, 0x97, 0x2e, 0xf8, 0x65, 0xf6,
+        0x75, 0x07, 0x04, 0x49, 0x33, 0xe4, 0xd9, 0xb9, 0xd0, 0x42, 0xc7, 0x6c, 0x90, 0x00, 0x8e,
+        0x6f, 0x50, 0x01, 0xc5, 0xda, 0x47, 0x3f, 0xcd, 0x69, 0xa2, 0xe2, 0x7a, 0xa7, 0xc6, 0x93,
+        0x0f, 0x0a, 0x06, 0xe6, 0x2b, 0x96, 0xa3, 0x1c, 0xaf, 0x6a, 0x12, 0x84, 0x39, 0xe7, 0xb0,
+        0x82, 0xf7, 0xfe, 0x9d, 0x87, 0x5c, 0x81, 0x35, 0xde, 0xb4, 0xa5, 0xfc, 0x80, 0xef, 0xcb,
+        0xbb, 0x6b, 0x76, 0xba, 0x5a, 0x7d, 0x78, 0x0b, 0x95, 0xe3, 0xad, 0x74, 0x98, 0x3b, 0x36,
+        0x64, 0x6d, 0xdc, 0xf0, 0x59, 0xa9, 0x4c, 0x17, 0x7f, 0x91, 0xb8, 0xc9, 0x57, 0x1b, 0xe0,
+        0x61,
+    ],
+];
diff --git a/kupyna512/src/sub_units/t_xor_plus/tests/mod.rs b/kupyna512/src/sub_units/t_xor_plus/tests/mod.rs
new file mode 100644
index 00000000..24971c08
--- /dev/null
+++ b/kupyna512/src/sub_units/t_xor_plus/tests/mod.rs
@@ -0,0 +1,2 @@
+mod test_xor_plus;
+mod test_individual_layers;
\ No newline at end of file
diff --git a/kupyna512/src/sub_units/t_xor_plus/tests/test_individual_layers.rs b/kupyna512/src/sub_units/t_xor_plus/tests/test_individual_layers.rs
new file mode 100644
index 00000000..44bbc4e5
--- /dev/null
+++ b/kupyna512/src/sub_units/t_xor_plus/tests/test_individual_layers.rs
@@ -0,0 +1,146 @@
+use crate::sub_units::t_xor_plus::*;
+
+#[test]
+fn test_add_constant_xor() {
+    let input = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+    let expected_output = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x18, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x30, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x28, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x60, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x78, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x50, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x48, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0xC0, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0xD8, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0xF0, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0xE8, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0xA0, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0xB8,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x90, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x88, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+    let input_matrix = block_to_matrix(&input);
+    let result = add_constant_xor(input_matrix, 0);
+    assert_eq!(result, block_to_matrix(&expected_output));
+}
+
+#[test]
+fn test_add_constant_plus() {
+    let input = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+    let expected_output = [
+        0xF3, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xFB, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE,
+        0xEF, 0x03, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0xE8, 0x0B, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0xE0, 0x13, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0xD8, 0x1B, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0xD0, 0x23, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0xC8, 0x2B, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0xC0, 0x33, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0xB8, 0x3B, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0xB0, 0x43, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0xA8, 0x4B, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0xA0, 0x53, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x98, 0x5B,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x90, 0x63, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x88,
+        0x6B, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x80,
+    ];
+    let input_matrix = block_to_matrix(&input);
+    let result = add_constant_plus(input_matrix, 0);
+    assert_eq!(result, block_to_matrix(&expected_output));
+}
+
+#[test]
+fn test_s_box_layer() {
+    let input = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x18, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x30, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x28, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x60, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x78, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x50, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x48, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0xC0, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0xD8, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0xF0, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0xE8, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0xA0, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0xB8,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x90, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x88, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+    let expected_output = [
+        0xA8, 0xBB, 0x9A, 0x4D, 0x6B, 0xCB, 0x45, 0x2A, 0x79, 0x3A, 0xDF, 0xB3, 0x17, 0x90, 0x51,
+        0x1F, 0x92, 0x15, 0x2B, 0x3D, 0xC9, 0x1C, 0xBB, 0x83, 0x1F, 0x5C, 0x71, 0xD5, 0x6F, 0x57,
+        0x16, 0xBD, 0x34, 0xF6, 0xC0, 0x02, 0xB4, 0xF4, 0xAD, 0x11, 0x8E, 0x0F, 0x7A, 0x5E, 0x49,
+        0x6D, 0xD1, 0x66, 0x2E, 0x26, 0xC4, 0x45, 0xD1, 0x5D, 0xB7, 0x94, 0x9C, 0x14, 0x0E, 0x1A,
+        0x58, 0x10, 0xB2, 0xDF, 0x2F, 0x6B, 0xD7, 0x0E, 0x42, 0x33, 0xC3, 0x86, 0xC4, 0x9B, 0x4E,
+        0x85, 0x8F, 0x95, 0xCB, 0x99, 0x81, 0x63, 0x4F, 0xEE, 0x96, 0x3C, 0x55, 0x30, 0x12, 0x49,
+        0x18, 0xB1, 0xBC, 0x37, 0xE6, 0x71, 0x78, 0x2B, 0x8F, 0xFD, 0x6A, 0x45, 0xB9, 0xAA, 0x1C,
+        0x0D, 0x2F, 0xAB, 0x38, 0x8C, 0xDA, 0x60, 0xEB, 0xDC, 0x05, 0x0C, 0x36, 0xB5, 0x6C, 0xEC,
+        0xCD, 0x62, 0xB1, 0x7C, 0x14, 0xA5, 0x5E, 0x5B,
+    ];
+    let input_matrix = block_to_matrix(&input);
+    let result = s_box_layer(input_matrix);
+    assert_eq!(result, block_to_matrix(&expected_output));
+}
+
+#[test]
+fn test_rotate_rows() {
+    let input = [
+        0xA8, 0xBB, 0x9A, 0x4D, 0x6B, 0xCB, 0x45, 0x2A, 0x79, 0x3A, 0xDF, 0xB3, 0x17, 0x90, 0x51,
+        0x1F, 0x92, 0x15, 0x2B, 0x3D, 0xC9, 0x1C, 0xBB, 0x83, 0x1F, 0x5C, 0x71, 0xD5, 0x6F, 0x57,
+        0x16, 0xBD, 0x34, 0xF6, 0xC0, 0x02, 0xB4, 0xF4, 0xAD, 0x11, 0x8E, 0x0F, 0x7A, 0x5E, 0x49,
+        0x6D, 0xD1, 0x66, 0x2E, 0x26, 0xC4, 0x45, 0xD1, 0x5D, 0xB7, 0x94, 0x9C, 0x14, 0x0E, 0x1A,
+        0x58, 0x10, 0xB2, 0xDF, 0x2F, 0x6B, 0xD7, 0x0E, 0x42, 0x33, 0xC3, 0x86, 0xC4, 0x9B, 0x4E,
+        0x85, 0x8F, 0x95, 0xCB, 0x99, 0x81, 0x63, 0x4F, 0xEE, 0x96, 0x3C, 0x55, 0x30, 0x12, 0x49,
+        0x18, 0xB1, 0xBC, 0x37, 0xE6, 0x71, 0x78, 0x2B, 0x8F, 0xFD, 0x6A, 0x45, 0xB9, 0xAA, 0x1C,
+        0x0D, 0x2F, 0xAB, 0x38, 0x8C, 0xDA, 0x60, 0xEB, 0xDC, 0x05, 0x0C, 0x36, 0xB5, 0x6C, 0xEC,
+        0xCD, 0x62, 0xB1, 0x7C, 0x14, 0xA5, 0x5E, 0x5B,
+    ];
+    let expected_output = [
+        0xA8, 0x62, 0x05, 0xAB, 0x6A, 0x37, 0x55, 0x66, 0x79, 0xBB, 0xB1, 0x0C, 0x38, 0x45, 0xE6,
+        0x94, 0x92, 0x3A, 0x9A, 0x7C, 0x36, 0x8C, 0xB9, 0xDF, 0x1F, 0x15, 0xDF, 0x4D, 0x14, 0xB5,
+        0xDA, 0x86, 0x34, 0x5C, 0x2B, 0xB3, 0x6B, 0xA5, 0x6C, 0x99, 0x8E, 0xF6, 0x71, 0x3D, 0x17,
+        0xCB, 0x5E, 0x30, 0x2E, 0x0F, 0xC0, 0xD5, 0xC9, 0x90, 0x45, 0x71, 0x9C, 0x26, 0x7A, 0x02,
+        0x6F, 0x1C, 0x51, 0xAA, 0x2F, 0x14, 0xC4, 0x5E, 0xB4, 0x57, 0xBB, 0x60, 0xC4, 0x6B, 0x0E,
+        0x45, 0x49, 0xF4, 0x16, 0xEC, 0x81, 0x9B, 0xD7, 0x1A, 0xD1, 0x6D, 0xAD, 0x5B, 0x12, 0x63,
+        0x4E, 0x0E, 0x58, 0x5D, 0xD1, 0x2A, 0x78, 0x49, 0x4F, 0x85, 0x42, 0x10, 0xB7, 0x1F, 0x1C,
+        0x2B, 0x18, 0xEE, 0x8F, 0x33, 0xB2, 0x83, 0xEB, 0x0D, 0x8F, 0xB1, 0x96, 0x95, 0xC3, 0xBD,
+        0xCD, 0xDC, 0x2F, 0xFD, 0xBC, 0x3C, 0xCB, 0x11,
+    ];
+    let input_matrix = block_to_matrix(&input);
+    let result = rotate_rows(input_matrix);
+    assert_eq!(result, block_to_matrix(&expected_output));
+}
+
+#[test]
+fn test_mix_columns() {
+    let input = [
+        0xA8, 0x62, 0x05, 0xAB, 0x6A, 0x37, 0x55, 0x66, 0x79, 0xBB, 0xB1, 0x0C, 0x38, 0x45, 0xE6,
+        0x94, 0x92, 0x3A, 0x9A, 0x7C, 0x36, 0x8C, 0xB9, 0xDF, 0x1F, 0x15, 0xDF, 0x4D, 0x14, 0xB5,
+        0xDA, 0x86, 0x34, 0x5C, 0x2B, 0xB3, 0x6B, 0xA5, 0x6C, 0x99, 0x8E, 0xF6, 0x71, 0x3D, 0x17,
+        0xCB, 0x5E, 0x30, 0x2E, 0x0F, 0xC0, 0xD5, 0xC9, 0x90, 0x45, 0x71, 0x9C, 0x26, 0x7A, 0x02,
+        0x6F, 0x1C, 0x51, 0xAA, 0x2F, 0x14, 0xC4, 0x5E, 0xB4, 0x57, 0xBB, 0x60, 0xC4, 0x6B, 0x0E,
+        0x45, 0x49, 0xF4, 0x16, 0xEC, 0x81, 0x9B, 0xD7, 0x1A, 0xD1, 0x6D, 0xAD, 0x5B, 0x12, 0x63,
+        0x4E, 0x0E, 0x58, 0x5D, 0xD1, 0x2A, 0x78, 0x49, 0x4F, 0x85, 0x42, 0x10, 0xB7, 0x1F, 0x1C,
+        0x2B, 0x18, 0xEE, 0x8F, 0x33, 0xB2, 0x83, 0xEB, 0x0D, 0x8F, 0xB1, 0x96, 0x95, 0xC3, 0xBD,
+        0xCD, 0xDC, 0x2F, 0xFD, 0xBC, 0x3C, 0xCB, 0x11,
+    ];
+    let expected_output = [
+        0x86, 0xC3, 0x77, 0x98, 0xD2, 0xC3, 0x41, 0xA0, 0x3D, 0x40, 0xB8, 0xB9, 0xE2, 0xD0, 0x21,
+        0xB8, 0xED, 0xF7, 0xEC, 0x7C, 0x76, 0x24, 0x85, 0x2B, 0xE4, 0x54, 0xC7, 0xEE, 0x3A, 0x2A,
+        0xAD, 0x4E, 0x9D, 0x55, 0x30, 0x9E, 0xD9, 0x95, 0x27, 0xD0, 0x92, 0x04, 0xD4, 0x0B, 0x63,
+        0xDC, 0x5B, 0x6F, 0x4D, 0x25, 0x90, 0xF2, 0x22, 0x83, 0x18, 0x18, 0x18, 0x19, 0xA8, 0x01,
+        0xE2, 0x6A, 0x90, 0x90, 0x2B, 0xE1, 0xE2, 0xD9, 0xF0, 0x51, 0x81, 0xF4, 0x59, 0x6E, 0xFA,
+        0xBC, 0x35, 0xF9, 0x84, 0xEB, 0x0C, 0xCB, 0x22, 0xFC, 0xB2, 0x2A, 0xDC, 0x5C, 0x98, 0xD3,
+        0xED, 0x83, 0x95, 0xCD, 0x50, 0xD4, 0xCE, 0x5A, 0x52, 0x16, 0x8E, 0xD8, 0x8C, 0x03, 0x08,
+        0x1D, 0x60, 0xB9, 0xB2, 0x8B, 0xAE, 0x4D, 0xFE, 0xA8, 0x3F, 0xFB, 0x07, 0xF1, 0x35, 0xB5,
+        0x71, 0x78, 0xE6, 0xC8, 0x9B, 0x20, 0x6A, 0xD3,
+    ];
+    let input_matrix = block_to_matrix(&input);
+    let result = mix_columns(input_matrix);
+    assert_eq!(result, block_to_matrix(&expected_output));
+}
diff --git a/kupyna512/src/sub_units/t_xor_plus/tests/test_xor_plus.rs b/kupyna512/src/sub_units/t_xor_plus/tests/test_xor_plus.rs
new file mode 100644
index 00000000..01fecae9
--- /dev/null
+++ b/kupyna512/src/sub_units/t_xor_plus/tests/test_xor_plus.rs
@@ -0,0 +1,63 @@
+use crate::sub_units::t_xor_plus::{t_plus_l, t_xor_l};
+
+#[test]
+fn test_t_xor_l() {
+    let input = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+
+    let expected_output = [
+        0x60, 0x4B, 0x9D, 0xCF, 0x7E, 0xAA, 0x57, 0x85, 0x94, 0xD1, 0x83, 0xEE, 0xF2, 0xDD, 0x97,
+        0xA3, 0x2C, 0x11, 0x1C, 0x81, 0x70, 0xC0, 0xA5, 0x08, 0x6A, 0x08, 0xC9, 0xE4, 0x28, 0x81,
+        0x11, 0x32, 0x31, 0xBE, 0xC7, 0xB7, 0x1D, 0x0E, 0xE3, 0x1D, 0xE8, 0x36, 0x3B, 0x4A, 0xA6,
+        0xAF, 0x89, 0x0B, 0xDE, 0xEE, 0x5C, 0x96, 0x66, 0x3A, 0x44, 0x38, 0x3A, 0x40, 0x09, 0x30,
+        0x60, 0xE7, 0x65, 0x15, 0x2D, 0xEB, 0xEC, 0xD2, 0x5B, 0x83, 0x42, 0xC4, 0xEF, 0x4E, 0x75,
+        0x0F, 0xC3, 0xF4, 0x81, 0x4F, 0xA9, 0xE1, 0xD1, 0x1F, 0xE7, 0xF6, 0xF8, 0xCF, 0x32, 0x72,
+        0xE7, 0xE1, 0x61, 0x4F, 0x91, 0xAD, 0x6F, 0x01, 0xF7, 0x28, 0xD8, 0xDB, 0xBE, 0x1F, 0x2A,
+        0xC1, 0x97, 0x77, 0x1E, 0x37, 0x8F, 0x8D, 0xD7, 0xD1, 0x31, 0x32, 0x7B, 0xF1, 0xA9, 0x43,
+        0xA9, 0x55, 0xF1, 0xF7, 0xC8, 0x32, 0xAD, 0xF3,
+    ];
+
+    let rounds = 14;
+    let result = t_xor_l(&input, rounds);
+    assert_eq!(result, expected_output);
+}
+
+#[test]
+fn test_t_plus_l() {
+    let input = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+
+    let expected_output = [
+        0x36, 0x57, 0x5D, 0x99, 0x30, 0x36, 0xAF, 0xDE, 0xB2, 0x65, 0x4C, 0x1E, 0x13, 0x66, 0x0A,
+        0x9D, 0x4F, 0x0E, 0x10, 0x5C, 0xA2, 0x33, 0x6F, 0x2B, 0xB3, 0x69, 0x00, 0x45, 0x25, 0x9A,
+        0x1A, 0x9D, 0x3F, 0x24, 0x85, 0x07, 0xC3, 0x42, 0xA7, 0x0B, 0x42, 0xF7, 0x49, 0x81, 0xEC,
+        0xE4, 0x6D, 0xD0, 0x5E, 0x1D, 0x30, 0x9F, 0x77, 0x4E, 0x1E, 0xD2, 0x13, 0x24, 0x7C, 0xC8,
+        0x21, 0x46, 0x16, 0x73, 0xC7, 0x41, 0x9A, 0xE1, 0x2B, 0x93, 0x61, 0xF3, 0x2C, 0x75, 0x38,
+        0xC1, 0x59, 0x09, 0xB1, 0x97, 0xE2, 0x0F, 0x9E, 0x09, 0xDD, 0x28, 0xCD, 0xD4, 0xD7, 0xC2,
+        0x34, 0xDB, 0xDB, 0x47, 0x93, 0x18, 0xA2, 0x58, 0xA7, 0x18, 0x0B, 0x18, 0x33, 0x17, 0x8A,
+        0x20, 0xFC, 0xFE, 0x05, 0xA6, 0x06, 0x4F, 0xD7, 0xB1, 0xEA, 0x96, 0x07, 0x99, 0x5E, 0x98,
+        0xD9, 0x0D, 0x2D, 0x55, 0xDC, 0xF7, 0x2F, 0x5F,
+    ];
+
+    let rounds = 14;
+    let result = t_plus_l(&input, rounds);
+    assert_eq!(result, expected_output);
+}
diff --git a/kupyna512/src/tests/blocking_tests.rs b/kupyna512/src/tests/blocking_tests.rs
new file mode 100644
index 00000000..bb257df9
--- /dev/null
+++ b/kupyna512/src/tests/blocking_tests.rs
@@ -0,0 +1,218 @@
+use crate::{pad_message, divide_into_blocks};
+
+
+const STATE_SIZE_512: usize = 1024;
+
+#[test]
+fn block_test_0() {
+    let message: [u8; 0] = [];
+
+    let expected_block_count = 1;
+
+    let padded_message = pad_message(&message,0, STATE_SIZE_512);
+
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE_512);
+
+    assert_eq!(blocks.len(), expected_block_count);
+
+    // check that all the blocks have equal length
+    let block_len = STATE_SIZE_512 / 8;
+    for block in blocks {
+        assert_eq!(block.len(), block_len);
+    }
+}
+
+#[test]
+fn block_test_8() {
+    let message: [u8; 1] = [0xFF];
+
+    let expected_block_count = 1;
+
+    let padded_message = pad_message(&message,8, STATE_SIZE_512);
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE_512);
+
+    assert_eq!(blocks.len(), expected_block_count);
+
+    // check that all the blocks have equal length
+    let block_len = STATE_SIZE_512 / 8;
+    for block in blocks {
+        assert_eq!(block.len(), block_len);
+    }
+}
+
+#[test]
+fn block_test_512() {
+    let message: [u8; 64] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F,
+    ];
+
+    let expected_block_count = 1;
+
+    let padded_message = pad_message(&message,512, STATE_SIZE_512);
+
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE_512);
+
+    assert_eq!(blocks.len(), expected_block_count);
+
+    // check that all the blocks have equal length
+    let block_len = STATE_SIZE_512 / 8;
+    for block in blocks {
+        assert_eq!(block.len(), block_len);
+    }
+}
+
+#[test]
+fn block_test_510() {
+    let message: [u8; 64] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3C,
+    ];
+
+    let expected_block_count = 1;
+
+    let padded_message = pad_message(&message,510, STATE_SIZE_512);
+
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE_512);
+
+    assert_eq!(blocks.len(), expected_block_count);
+
+    // check that all the blocks have equal length
+    let block_len = STATE_SIZE_512 / 8;
+    for block in blocks {
+        assert_eq!(block.len(), block_len);
+    }
+
+}
+
+#[test]
+fn block_test_1024() {
+    let message: [u8; 128] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+
+    let expected_block_count = 2;
+
+    let padded_message = pad_message(&message,1024, STATE_SIZE_512);
+
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE_512);
+
+    assert_eq!(blocks.len(), expected_block_count);
+
+    // check that all the blocks have equal length
+    let block_len = STATE_SIZE_512 / 8;
+    for block in blocks {
+        assert_eq!(block.len(), block_len);
+    }
+}
+
+#[test]
+fn block_test_2048() {
+    let message: [u8; 256] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
+        0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+        0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4,
+        0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+        0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2,
+        0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1,
+        0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0,
+        0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
+        0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE,
+        0xFF,
+    ];
+
+    let expected_block_count = 3;
+
+    let padded_message = pad_message(&message,2048, STATE_SIZE_512);
+
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE_512);
+
+    assert_eq!(blocks.len(), expected_block_count);
+
+    // check that all the blocks have equal length
+    let block_len = STATE_SIZE_512 / 8;
+    for block in blocks {
+        assert_eq!(block.len(), block_len);
+    }
+}
+
+#[test]
+fn block_test_1536() {
+    let message: [u8; 192] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
+        0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+        0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4,
+        0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+        0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
+    ];
+
+    let expected_block_count = 2;
+
+    let padded_message = pad_message(&message,1536, STATE_SIZE_512);
+
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE_512);
+
+    assert_eq!(blocks.len(), expected_block_count);
+
+    // check that all the blocks have equal length
+    let block_len = STATE_SIZE_512 / 8;
+    for block in blocks {
+        assert_eq!(block.len(), block_len);
+    }
+}
+
+#[test]
+fn block_test_655() {
+    let message: [u8; 82] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x50,
+    ];
+
+    let expected_block_count = 1;
+
+    let padded_message = pad_message(&message,655, STATE_SIZE_512);
+
+    let blocks = divide_into_blocks(&padded_message, STATE_SIZE_512);
+
+    assert_eq!(blocks.len(), expected_block_count);
+
+    // check that all the blocks have equal length
+    let block_len = STATE_SIZE_512 / 8;
+    for block in blocks {
+        assert_eq!(block.len(), block_len);
+    }
+}
\ No newline at end of file
diff --git a/kupyna512/src/tests/hashing_tests.rs b/kupyna512/src/tests/hashing_tests.rs
new file mode 100644
index 00000000..797f4fe3
--- /dev/null
+++ b/kupyna512/src/tests/hashing_tests.rs
@@ -0,0 +1,207 @@
+use crate::hash;
+
+#[test]
+fn hash_test_0() {
+    let message: [u8; 0] = [];
+    let message_length = 0;
+
+    let expected_hash = [
+        0x65, 0x6B, 0x2F, 0x4C, 0xD7, 0x14, 0x62, 0x38, 0x8B, 0x64, 0xA3, 0x70, 0x43, 0xEA, 0x55,
+        0xDB, 0xE4, 0x45, 0xD4, 0x52, 0xAE, 0xCD, 0x46, 0xC3, 0x29, 0x83, 0x43, 0x31, 0x4E, 0xF0,
+        0x40, 0x19, 0xBC, 0xFA, 0x3F, 0x04, 0x26, 0x5A, 0x98, 0x57, 0xF9, 0x1B, 0xE9, 0x1F, 0xCE,
+        0x19, 0x70, 0x96, 0x18, 0x7C, 0xED, 0xA7, 0x8C, 0x9C, 0x1C, 0x02, 0x1C, 0x29, 0x4A, 0x06,
+        0x89, 0x19, 0x85, 0x38,
+    ];
+
+    let actual_hash = hash(message.to_vec(), Some(message_length)).unwrap();
+
+    assert_eq!(actual_hash, expected_hash);
+}
+
+#[test]
+fn hash_test_8() {
+    let message: [u8; 1] = [0xFF];
+    let message_length = 8;
+
+    let expected_hash = [
+        0x87, 0x1B, 0x18, 0xCF, 0x75, 0x4B, 0x72, 0x74, 0x03, 0x07, 0xA9, 0x7B, 0x44, 0x9A, 0xBE,
+        0xB3, 0x2B, 0x64, 0x44, 0x4C, 0xC0, 0xD5, 0xA4, 0xD6, 0x58, 0x30, 0xAE, 0x54, 0x56, 0x83,
+        0x7A, 0x72, 0xD8, 0x45, 0x8F, 0x12, 0xC8, 0xF0, 0x6C, 0x98, 0xC6, 0x16, 0xAB, 0xE1, 0x18,
+        0x97, 0xF8, 0x62, 0x63, 0xB5, 0xCB, 0x77, 0xC4, 0x20, 0xFB, 0x37, 0x53, 0x74, 0xBE, 0xC5,
+        0x2B, 0x6D, 0x02, 0x92,
+    ];
+
+    let actual_hash = hash(message.to_vec(), Some(message_length)).unwrap();
+
+    assert_eq!(actual_hash, expected_hash);
+}
+
+#[test]
+fn hash_test_510() {
+    let message: [u8; 64] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3C,
+    ];
+    let message_length = 510;
+
+    let expected_hash = [
+        0x2F, 0x3B, 0xBA, 0xC9, 0x8E, 0x87, 0x71, 0xD6, 0xE3, 0xB8, 0xAA, 0x30, 0x15, 0x3A, 0xBC,
+        0x4D, 0x0C, 0x29, 0x85, 0xE9, 0x1D, 0xA1, 0xB5, 0x56, 0x8F, 0xD1, 0xBD, 0xD7, 0x05, 0xCC,
+        0xAB, 0x7E, 0xE8, 0xD9, 0x5D, 0x2F, 0xC9, 0x8B, 0xFA, 0x53, 0x22, 0xA2, 0x41, 0xE0, 0x9C,
+        0x89, 0x6B, 0x58, 0x28, 0x4C, 0x83, 0xF2, 0x48, 0x8C, 0xF9, 0x43, 0xE4, 0xB3, 0xDE, 0x43,
+        0xE0, 0x5F, 0x0D, 0xEA,
+    ];
+
+    let actual_hash = hash(message.to_vec(), Some(message_length)).unwrap();
+
+    assert_eq!(actual_hash, expected_hash);
+}
+
+#[test]
+fn hash_test_512() {
+    let message: [u8; 64] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F,
+    ];
+    let message_length = 512;
+
+    let expected_hash = [
+        0x38, 0x13, 0xE2, 0x10, 0x91, 0x18, 0xCD, 0xFB, 0x5A, 0x6D, 0x5E, 0x72, 0xF7, 0x20, 0x8D,
+        0xCC, 0xC8, 0x0A, 0x2D, 0xFB, 0x3A, 0xFD, 0xFB, 0x02, 0xF4, 0x69, 0x92, 0xB5, 0xED, 0xBE,
+        0x53, 0x6B, 0x35, 0x60, 0xDD, 0x1D, 0x7E, 0x29, 0xC6, 0xF5, 0x39, 0x78, 0xAF, 0x58, 0xB4,
+        0x44, 0xE3, 0x7B, 0xA6, 0x85, 0xC0, 0xDD, 0x91, 0x05, 0x33, 0xBA, 0x5D, 0x78, 0xEF, 0xFF,
+        0xC1, 0x3D, 0xE6, 0x2A,
+    ];
+
+    let actual_hash = hash(message.to_vec(), Some(message_length)).unwrap();
+
+    assert_eq!(actual_hash, expected_hash);
+}
+
+#[test]
+fn hash_test_655() {
+    let message: [u8; 82] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x50,
+    ];
+    let message_length = 655;
+
+    let expected_hash = [
+        0x01, 0xB7, 0xBD, 0xA1, 0xDB, 0xA7, 0x7D, 0x73, 0x79, 0xF5, 0x3C, 0x2A, 0x49, 0x8A, 0x39,
+        0x0D, 0xE5, 0xE6, 0x88, 0xA1, 0x2B, 0xC7, 0x5F, 0xEE, 0x9E, 0x01, 0x0C, 0xB6, 0xFE, 0xBE,
+        0xD3, 0xB9, 0xC7, 0x02, 0x39, 0x31, 0xC7, 0x4A, 0x7B, 0x55, 0x16, 0x8A, 0x15, 0x04, 0x7D,
+        0x5E, 0x2C, 0xB7, 0x8A, 0x8B, 0x5C, 0xA2, 0xF7, 0x5E, 0x05, 0xE8, 0x0C, 0xA3, 0x98, 0x03,
+        0x0E, 0x02, 0xC7, 0xAA,
+    ];
+
+    let actual_hash = hash(message.to_vec(), Some(message_length)).unwrap();
+
+    assert_eq!(actual_hash, expected_hash);
+}
+
+#[test]
+fn hash_test_1024() {
+    let message: [u8; 128] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+    let message_length = 1024;
+
+    let expected_hash = [
+        0x76, 0xED, 0x1A, 0xC2, 0x8B, 0x1D, 0x01, 0x43, 0x01, 0x3F, 0xFA, 0x87, 0x21, 0x3B, 0x40,
+        0x90, 0xB3, 0x56, 0x44, 0x12, 0x63, 0xC1, 0x3E, 0x03, 0xFA, 0x06, 0x0A, 0x8C, 0xAD, 0xA3,
+        0x2B, 0x97, 0x96, 0x35, 0x65, 0x7F, 0x25, 0x6B, 0x15, 0xD5, 0xFC, 0xA4, 0xA1, 0x74, 0xDE,
+        0x02, 0x9F, 0x0B, 0x1B, 0x43, 0x87, 0xC8, 0x78, 0xFC, 0xC1, 0xC0, 0x0E, 0x87, 0x05, 0xD7,
+        0x83, 0xFD, 0x7F, 0xFE,
+    ];
+
+    let actual_hash = hash(message.to_vec(), Some(message_length)).unwrap();
+
+    assert_eq!(actual_hash, expected_hash);
+}
+
+#[test]
+fn hash_test_1536() {
+    let message: [u8; 192] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
+        0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+        0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4,
+        0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+        0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
+    ];
+    let message_length = 1536;
+
+    let expected_hash = [
+        0xB1, 0x89, 0xBF, 0xE9, 0x87, 0xF6, 0x82, 0xF5, 0xF1, 0x67, 0xF0, 0xD7, 0xFA, 0x56, 0x53,
+        0x30, 0xE1, 0x26, 0xB6, 0xE5, 0x92, 0xB1, 0xC5, 0x5D, 0x44, 0x29, 0x90, 0x64, 0xEF, 0x95,
+        0xB1, 0xA5, 0x7F, 0x3C, 0x2D, 0x0E, 0xCF, 0x17, 0x86, 0x9D, 0x1D, 0x19, 0x9E, 0xBB, 0xD0,
+        0x2E, 0x88, 0x57, 0xFB, 0x8A, 0xDD, 0x67, 0xA8, 0xC3, 0x1F, 0x56, 0xCD, 0x82, 0xC0, 0x16,
+        0xCF, 0x74, 0x31, 0x21,
+    ];
+
+    let actual_hash = hash(message.to_vec(), Some(message_length)).unwrap();
+
+    assert_eq!(actual_hash, expected_hash);
+}
+
+#[test]
+fn hash_test_2048() {
+    let message: [u8; 256] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
+        0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+        0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4,
+        0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+        0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2,
+        0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1,
+        0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0,
+        0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
+        0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE,
+        0xFF,
+    ];
+    let message_length = 2048;
+
+    let expected_hash = [
+        0x0D, 0xD0, 0x3D, 0x73, 0x50, 0xC4, 0x09, 0xCB, 0x3C, 0x29, 0xC2, 0x58, 0x93, 0xA0, 0x72,
+        0x4F, 0x6B, 0x13, 0x3F, 0xA8, 0xB9, 0xEB, 0x90, 0xA6, 0x4D, 0x1A, 0x8F, 0xA9, 0x3B, 0x56,
+        0x55, 0x66, 0x11, 0xEB, 0x18, 0x7D, 0x71, 0x5A, 0x95, 0x6B, 0x10, 0x7E, 0x3B, 0xFC, 0x76,
+        0x48, 0x22, 0x98, 0x13, 0x3A, 0x9C, 0xE8, 0xCB, 0xC0, 0xBD, 0x5E, 0x14, 0x36, 0xA5, 0xB1,
+        0x97, 0x28, 0x4F, 0x7E,
+    ];
+
+    let actual_hash = hash(message.to_vec(), Some(message_length)).unwrap();
+
+    assert_eq!(actual_hash, expected_hash);
+}
diff --git a/kupyna512/src/tests/mod.rs b/kupyna512/src/tests/mod.rs
new file mode 100644
index 00000000..5071554b
--- /dev/null
+++ b/kupyna512/src/tests/mod.rs
@@ -0,0 +1,3 @@
+mod padding_tests;
+mod blocking_tests;
+mod hashing_tests;
diff --git a/kupyna512/src/tests/padding_tests.rs b/kupyna512/src/tests/padding_tests.rs
new file mode 100644
index 00000000..95415088
--- /dev/null
+++ b/kupyna512/src/tests/padding_tests.rs
@@ -0,0 +1,268 @@
+use crate::pad_message;
+
+const STATE_SIZE_512: usize = 1024;
+
+#[test]
+fn pad_test_0() {
+    let message: [u8; 0] = [];
+
+    let expected_output: [u8; 128] = [
+        0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+
+    let padded_message = pad_message(&message,0, STATE_SIZE_512);
+
+    assert_eq!(padded_message, expected_output);
+}
+
+#[test]
+fn pad_test_8() {
+    let message: [u8; 1] = [0xFF];
+
+    let expected_output: [u8; 128] = [
+        0xFF, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+
+    let padded_message = pad_message(&message,8, STATE_SIZE_512);
+
+    assert_eq!(padded_message, expected_output);
+}
+
+#[test]
+fn pad_test_510() {
+    let message: [u8; 64] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3C,
+    ];
+
+    let expected_output: [u8; 128] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3E, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFE, 0x01, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+
+    let padded_message = pad_message(&message,510, STATE_SIZE_512);
+
+    assert_eq!(padded_message, expected_output);
+}
+
+#[test]
+fn pad_test_512() {
+    let message: [u8; 64] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F,
+    ];
+
+    let expected_output: [u8; 128] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+
+    let padded_message = pad_message(&message,512, STATE_SIZE_512);
+
+    assert_eq!(padded_message, expected_output);
+}
+
+#[test]
+fn pad_test_1024() {
+    let message: [u8; 128] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    ];
+
+    let expected_output: [u8; 256] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+
+    let padded_message = pad_message(&message,1024, STATE_SIZE_512);
+
+    assert_eq!(padded_message, expected_output);
+}
+
+#[test]
+fn pad_test_2048() {
+    let message: [u8; 256] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
+        0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+        0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4,
+        0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+        0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2,
+        0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1,
+        0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0,
+        0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
+        0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE,
+        0xFF,
+    ];
+
+    let expected_output: [u8; 384] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
+        0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+        0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4,
+        0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+        0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2,
+        0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1,
+        0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0,
+        0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
+        0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE,
+        0xFF, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+
+    let padded_message = pad_message(&message,2048, STATE_SIZE_512);
+
+    assert_eq!(padded_message, expected_output);
+}
+
+#[test]
+fn pad_test_1536() {
+    let message: [u8; 192] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
+        0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+        0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4,
+        0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+        0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
+    ];
+
+    let expected_output: [u8; 256] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+        0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+        0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86,
+        0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95,
+        0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4,
+        0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+        0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, 0x80, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+
+    let padded_message = pad_message(&message,1536, STATE_SIZE_512);
+
+    assert_eq!(padded_message, expected_output);
+}
+
+#[test]
+fn pad_test_655() {
+    let message: [u8; 82] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x50,
+    ];
+
+    let expected_output: [u8; 128] = [
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D,
+        0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C,
+        0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
+        0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+        0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x8F, 0x02, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+
+    let padded_message = pad_message(&message,655, STATE_SIZE_512);
+
+    assert_eq!(padded_message, expected_output);
+}