      <option value="des_encrypt">DES Encrypt</option>
        </select>
        <br><br>

        <label for="data">Data:</label>
        <input type="text" id="data" name="data" required>
        <br><br>

        <div id="keyField" style="display: none;">
            <label for="key">Key (for DES Encrypt):</label>
            <input type="text" id="key" name="key">
            <br><br>

            <label for="iv">IV (for DES Encrypt):</label>
            <input type="text" id="iv" name="iv">
           