flutter pub add dart_des根據套件公開資料產生的選型評估，僅供參考。
dart_des 是資料加密標準（DES）和三重 DES 加密演算法的純 Dart 實作。它提供安全、平台無關的加密運算，適用於需要對稱金鑰加密的應用程式。該套件支援所有主要平台，包括 Android、iOS、Web、macOS、Windows 和 Linux，非常適合需要傳統或標準化加密的跨平台應用程式。它不依賴原生程式碼，確保在各環境中行為一致。此函式庫專為需要實作基於 DES 的加密且無需外部相依性的開發者設計。
以下為關聯原始碼儲存庫的 README 原文快照，最新內容請造訪原始碼儲存庫。
This algorithm is a pure dart implementation of the DES and Triple DES algorithms (port of pyDES). Triple DES is either DES-EDE3 with a 24 byte key, or DES-EDE2 with a 16 byte key.
import 'dart:convert';
import 'package:convert/convert.dart';
import 'package:dart_des/dart_des.dart';
main() {
String key = '12345678'; // 8-byte
String message = 'Driving in from the edge of town';
List<int> encrypted;
List<int> decrypted;
List<int> iv = [1, 2, 3, 4, 5, 6, 7, 8];
print('key: $key');
print('message: $message');
DES desECB = DES(key: key.codeUnits, mode: DESMode.ECB);
encrypted = desECB.encrypt(message.codeUnits);
decrypted = desECB.decrypt(encrypted);
print('DES mode: ECB');
print('encrypted: $encrypted');
print('encrypted (hex): ${hex.encode(encrypted)}');
print('encrypted (base64): ${base64.encode(encrypted)}');
print('decrypted: $decrypted');
print('decrypted (hex): ${hex.encode(decrypted)}');
print('decrypted (utf8): ${utf8.decode(decrypted)}');
key = '123456781234567812345678'; // 24-byte
DES3 des3CBC = DES3(key: key.codeUnits, mode: DESMode.CBC, iv: iv);
encrypted = des3CBC.encrypt(message.codeUnits);
decrypted = des3CBC.decrypt(encrypted);
print('Triple DES mode: CBC');
print('encrypted: $encrypted');
print('encrypted (hex): ${hex.encode(encrypted)}');
print('encrypted (base64): ${base64.encode(encrypted)}');
print('decrypted: $decrypted');
print('decrypted (hex): ${hex.encode(decrypted)}');
print('decrypted (utf8): ${utf8.decode(decrypted)}');
}