diff --git a/app_crypto/lib/encrypt.dart b/app_crypto/lib/encrypt.dart
index 2a9bc2e..780e7db 100644
--- a/app_crypto/lib/encrypt.dart
+++ b/app_crypto/lib/encrypt.dart
@@ -1,4 +1,10 @@
 export 'package:tekartik_app_crypto/src/encrypt.dart'
     show encrypt, decrypt, StringEncrypter, defaultEncryptedFromRawPassword;
 
+export 'src/aes.dart'
+    show
+        aesEncrypterFromPassword,
+        encryptTextPassword16FromText,
+        aesDecrypt,
+        aesEncrypt;
 export 'src/salsa20.dart' show salsa20EncrypterFromPassword;
diff --git a/app_crypto/lib/src/aes.dart b/app_crypto/lib/src/aes.dart
new file mode 100644
index 0000000..ac59ae0
--- /dev/null
+++ b/app_crypto/lib/src/aes.dart
@@ -0,0 +1,91 @@
+import 'dart:convert';
+
+import 'package:crypto/crypto.dart';
+import 'package:encrypt/encrypt.dart';
+
+import 'encrypt.dart';
+
+/// Simple md5 hash
+String encryptTextPassword16FromText(String password) {
+  return base64Encode(md5.convert(utf8.encode(password)).bytes)
+      .substring(0, 16);
+}
+
+/// aes encrypted using any password (use MD5), random data prepended
+StringEncrypter aesEncrypterFromPassword(String password) {
+  return _AesStringEncrypter(_aesEncrypterFromPassword(password));
+}
+
+Encrypter _aesEncrypterFromPassword(String password) {
+  final key = Key.fromUtf8(password); // _generateEncryptPassword(password));
+  return Encrypter(AES(key));
+}
+
+class _AesStringEncrypter implements StringEncrypter {
+  final Encrypter encrypter;
+
+  _AesStringEncrypter(this.encrypter);
+  @override
+  String decrypt(String encrypted) {
+    // Read the initial value that was prepended
+    assert(encrypted.length >= 24);
+    final iv = base64.decode(encrypted.substring(0, 24));
+
+    // Extract the real input
+    encrypted = encrypted.substring(24);
+
+    // Decode the input
+    var decoded = encrypter.decrypt64(encrypted, iv: IV(iv));
+    return decoded;
+  }
+
+  IV _generateIv() {
+    final iv = IV.fromSecureRandom(16);
+    return iv;
+  }
+
+  @override
+  String encrypt(String input) {
+    final iv = _generateIv();
+
+    // Encode the input value
+    final encoded = encrypter.encrypt(input, iv: iv).base64;
+
+    var ivEncoded = iv.base64;
+    assert(ivEncoded.length == 24);
+    // Prepend the initial value
+    return '$ivEncoded$encoded';
+  }
+}
+
+class AesWithIVEntrypter extends _AesStringEncrypter {
+  final IV iv;
+
+  /// Must be 16 bytes
+  final String password;
+  AesWithIVEntrypter(this.password, this.iv)
+      : super(_aesEncrypterFromPassword(password));
+  @override
+  IV _generateIv() {
+    return iv;
+  }
+}
+
+/// encrypt the [decoded] text using [password].
+///
+/// [password] must be ascii character of length 16, 24 or 32.
+///
+/// returns a base 64 encrypted string.
+///
+/// Encryption used is AES.
+String aesEncrypt(String decoded, String password) =>
+    aesEncrypterFromPassword(password).encrypt(decoded);
+
+/// decrypt the [encoded] text using [password].
+///
+/// [encoded] is base 64 string got from the encrypt method using the same
+/// [password]
+///
+/// Encryption used is AES.
+String aesDecrypt(String encoded, String password) =>
+    aesEncrypterFromPassword(password).decrypt(encoded);
diff --git a/app_crypto/lib/src/encrypt.dart b/app_crypto/lib/src/encrypt.dart
index 44057e9..3073b6f 100644
--- a/app_crypto/lib/src/encrypt.dart
+++ b/app_crypto/lib/src/encrypt.dart
@@ -1,3 +1,5 @@
+import 'dart:typed_data';
+
 import 'package:encrypt/encrypt.dart';
 
 /// encrypt the [decoded] text using [password].
@@ -9,7 +11,7 @@ import 'package:encrypt/encrypt.dart';
 /// Encryption used is AES.
 String _encrypt(String decoded, String password) {
   final key = Key.fromUtf8(password);
-  final iv = IV.fromLength(16);
+  final iv = IV(Uint8List(16));
   final encrypter = Encrypter(AES(key));
   return encrypter.encrypt(decoded, iv: iv).base64;
 }
@@ -22,7 +24,7 @@ String _encrypt(String decoded, String password) {
 /// Encryption used is AES.
 String _decrypt(String encoded, String password) {
   final key = Key.fromUtf8(password);
-  final iv = IV.fromLength(16);
+  final iv = IV(Uint8List(16));
   final encrypter = Encrypter(AES(key));
   return encrypter.decrypt(Encrypted.fromBase64(encoded), iv: iv);
 }
diff --git a/app_crypto/lib/src/encrypt_codec.dart b/app_crypto/lib/src/encrypt_codec.dart
index 636fa97..8a57190 100644
--- a/app_crypto/lib/src/encrypt_codec.dart
+++ b/app_crypto/lib/src/encrypt_codec.dart
@@ -33,7 +33,7 @@ class EncryptCodec with Codec<String, String> {
       EncryptConverter(encrypter: encrypter);
 }
 
-/// String password
+/// String password - fixed IV with 0
 EncryptCodec defaultEncryptCodec({required String rawPassword}) =>
     EncryptCodec(encrypter: defaultEncryptedFromRawPassword(rawPassword));
 
diff --git a/app_crypto/pubspec.yaml b/app_crypto/pubspec.yaml
index 3068dd4..28e9c57 100644
--- a/app_crypto/pubspec.yaml
+++ b/app_crypto/pubspec.yaml
@@ -15,7 +15,9 @@ dependencies:
       ref: dart3a
     version: '>=0.10.7'
   meta: '>=1.1.6'
-  encrypt: ^5.0.3
+  encrypt: '>=3.0.0' # <=5.0.3'
+  # Temp aes issue limited to 5.0.1
+  # encrypt: '<=5.0.3'
   crypto:
   # Temp web compile issue
   pointycastle: '>=3.2.0-rc0'
@@ -23,7 +25,14 @@ dependencies:
 dev_dependencies:
   dev_test:
   test: '>=1.5.0'
+  # downgrade testing
+  file: '>=7.0.0'
   build_runner: '>=1.2.7'
   build_test: any
   build_web_compilers: any
   process_run: '>=0.12.0+1'
+
+_dependency_overrides:
+  encrypt:
+    git:
+      url: https://github.com/leocavalcante/encrypt
\ No newline at end of file
diff --git a/app_crypto/test/aes_test.dart b/app_crypto/test/aes_test.dart
index b2376a9..c169ec5 100644
--- a/app_crypto/test/aes_test.dart
+++ b/app_crypto/test/aes_test.dart
@@ -1,23 +1,98 @@
 import 'package:encrypt/encrypt.dart';
+import 'package:tekartik_app_crypto/encrypt.dart';
+import 'package:tekartik_app_crypto/src/aes.dart';
+import 'package:tekartik_app_crypto/src/generate_password.dart'
+    show generatePassword;
 import 'package:test/test.dart';
 
-String encrypt(String decoded, String password) {
-  final key = Key.fromUtf8(password);
-  final iv = IV.fromLength(16);
-  final encrypter = Encrypter(AES(key));
-  return encrypter.encrypt(decoded, iv: iv).base64;
-}
+void main() {
+  void aesRoundTrip(String decoded, String password) {
+    var encrypter = aesEncrypterFromPassword(password);
+    var encrypted = encrypter.encrypt(decoded);
+    print('${decoded.length}:${encrypted.length}');
+    encrypter = aesEncrypterFromPassword(password);
+    expect(encrypter.decrypt(encrypted), decoded);
+  }
 
-String decrypt(String encoded, String password) {
-  final key = Key.fromUtf8(password);
-  final iv = IV.fromLength(16);
-  final encrypter = Encrypter(AES(key));
-  return encrypter.decrypt(Encrypted.fromBase64(encoded), iv: iv);
-}
+  test('aes encrypt decrypt', () {
+    var password = r'E4x*$TwbkJC-xK4KGC4zJF9j*Rh&WLgR';
+    var encrypter = AesWithIVEntrypter(password, IV.allZerosOfLength(16));
 
-void main() {
-  test('AES encrypt/decrypt', () {
+    expect(encrypt('test', password), 'amGhyRRLUIoE59IiEys5Vw==');
+    expect(encrypter.encrypt('test'),
+        'AAAAAAAAAAAAAAAAAAAAAA==amGhyRRLUIoE59IiEys5Vw==');
+    expect(
+        encrypter.decrypt('AAAAAAAAAAAAAAAAAAAAAA==amGhyRRLUIoE59IiEys5Vw=='),
+        'test');
+  });
+
+  test('aes decrypt', () {
     var password = r'E4x*$TwbkJC-xK4KGC4zJF9j*Rh&WLgR';
-    expect(decrypt('amGhyRRLUIoE59IiEys5Vw==', password), 'test');
+    var encrypter = aesEncrypterFromPassword(password);
+
+    expect(
+        encrypter.encrypt('test'),
+        isNot(
+            'kEH3mkatSK4yiDu95hZj3Q==0aN1ouMw1HhKY6L8sibkgA==')); // - different each time
+    expect(
+        encrypter.decrypt('kEH3mkatSK4yiDu95hZj3Q==0aN1ouMw1HhKY6L8sibkgA=='),
+        'test');
+    expect(
+        aesDecrypt(
+            'kEH3mkatSK4yiDu95hZj3Q==0aN1ouMw1HhKY6L8sibkgA==', password),
+        'test');
+    expect(aesEncrypt('test', password),
+        isNot('19/EiVx5ICKR/IpS05DYmA==rqLU4PjkNP8W/SiI1dVgAA=='));
+    expect(
+        aesDecrypt(
+            '19/EiVx5ICKR/IpS05DYmA==rqLU4PjkNP8W/SiI1dVgAA==', password),
+        'test');
+    expect(aesDecrypt(aesEncrypt('test', password), password), 'test');
+  });
+  test('aes', () {
+    var aes = aesEncrypterFromPassword(encryptTextPassword16FromText('test'));
+    var encrypted = aes.encrypt('test');
+    aes = aesEncrypterFromPassword(encryptTextPassword16FromText('test'));
+    expect(aes.decrypt(encrypted), 'test');
+
+    String textWithLength(int length) {
+      return List.generate(length, (i) => i.toString().substring(0, 1)).join();
+    }
+
+    aesRoundTrip('test', encryptTextPassword16FromText('test'));
+    //aesRoundTrip('', '');
+    aesRoundTrip('1', encryptTextPassword16FromText('2'));
+    aesRoundTrip(textWithLength(4096),
+        encryptTextPassword16FromText(textWithLength(4096)));
+    // _salsa20RoundTrip(textWithLength(40960), textWithLength(40960));
+    aesRoundTrip(textWithLength(4096000),
+        encryptTextPassword16FromText(textWithLength(4096000)));
+
+    var password = generatePassword();
+    aes = aesEncrypterFromPassword(password);
+    var sw = Stopwatch()..start();
+    var count = 1000;
+    for (var i = 0; i < count; i++) {
+      aes.decrypt(aes.encrypt(textWithLength(count * 10)));
+    }
+    print('aes round trip: ${sw.elapsedMilliseconds} ms');
+    sw = Stopwatch()..start();
+
+    for (var i = 0; i < count; i++) {
+      aesDecrypt(aesEncrypt(textWithLength(count * 10), password), password);
+    }
+    print('aesDecrypt/aesEncrypt: ${sw.elapsedMilliseconds} ms');
+
+    var encrypteds = List.generate(count, (index) => '');
+    sw = Stopwatch()..start();
+    for (var i = 0; i < count; i++) {
+      encrypteds[i] = aes.encrypt(textWithLength(count * 10));
+    }
+    print('aes encrypt: ${sw.elapsedMilliseconds} ms');
+    sw = Stopwatch()..start();
+    for (var i = 0; i < count; i++) {
+      aes.decrypt(encrypteds[i]);
+    }
+    print('aes decrypt: ${sw.elapsedMilliseconds} ms');
   });
 }
diff --git a/app_crypto/test/crypto_test.dart b/app_crypto/test/crypto_test.dart
index 4bd8bbf..3bef1c1 100644
--- a/app_crypto/test/crypto_test.dart
+++ b/app_crypto/test/crypto_test.dart
@@ -8,14 +8,6 @@ void main() {
     expect(decrypt(encrypt(decoded, password), password), decoded);
   }
 
-  void salsa20RoundTrip(String decoded, String password) {
-    var encrypter = salsa20EncrypterFromPassword(password);
-    var encrypted = encrypter.encrypt(decoded);
-    print('${decoded.length}:${encrypted.length}');
-    encrypter = salsa20EncrypterFromPassword(password);
-    expect(encrypter.decrypt(encrypted), decoded);
-  }
-
   test('test', () {
     var password = r'E4x*$TwbkJC-xK4KGC4zJF9j*Rh&WLgR';
     expect(encrypt('test', password), 'amGhyRRLUIoE59IiEys5Vw==');
@@ -45,37 +37,15 @@ void main() {
     }
   });
 
-  test('generatePassword', () {
-    expect(generatePassword().length, 32);
-    expect(generatePassword(length: 64).length, 64);
-  });
-
-  test('salsa20', () {
-    var salsa = salsa20EncrypterFromPassword('test');
-    var encrypted = salsa.encrypt('test');
-    salsa = salsa20EncrypterFromPassword('test');
-    expect(salsa.decrypt(encrypted), 'test');
-
+  test('legacy', () {
     String textWithLength(int length) {
       return List.generate(length, (i) => i.toString().substring(0, 1)).join();
     }
 
-    salsa20RoundTrip('test', 'test');
-    salsa20RoundTrip('', '');
-    salsa20RoundTrip('1', '2');
-    salsa20RoundTrip(textWithLength(4096), textWithLength(4096));
-    // _salsa20RoundTrip(textWithLength(40960), textWithLength(40960));
-    salsa20RoundTrip(textWithLength(4096000), textWithLength(4096000));
-
     var password = generatePassword();
-    salsa = salsa20EncrypterFromPassword(password);
+
     var sw = Stopwatch()..start();
     var count = 1000;
-    for (var i = 0; i < count; i++) {
-      salsa.decrypt(salsa.encrypt(textWithLength(count * 10)));
-    }
-    print('salsa: ${sw.elapsedMilliseconds} ms');
-    sw = Stopwatch()..start();
 
     for (var i = 0; i < count; i++) {
       decrypt(encrypt(textWithLength(count * 10), password), password);
@@ -84,16 +54,6 @@ void main() {
 
     var encrypteds = List.generate(count, (index) => '');
     sw = Stopwatch()..start();
-    for (var i = 0; i < count; i++) {
-      encrypteds[i] = salsa.encrypt(textWithLength(count * 10));
-    }
-    print('salsa encrypt: ${sw.elapsedMilliseconds} ms');
-    sw = Stopwatch()..start();
-    for (var i = 0; i < count; i++) {
-      salsa.decrypt(encrypteds[i]);
-    }
-    print('salsa decrypt: ${sw.elapsedMilliseconds} ms');
-    sw = Stopwatch()..start();
     for (var i = 0; i < count; i++) {
       encrypteds[i] = encrypt(textWithLength(count * 10), password);
     }
diff --git a/app_crypto/test/password_generator_test.dart b/app_crypto/test/password_generator_test.dart
index 3215d7d..f605f15 100644
--- a/app_crypto/test/password_generator_test.dart
+++ b/app_crypto/test/password_generator_test.dart
@@ -5,5 +5,7 @@ void main() {
   test('generatePassword', () {
     expect(generatePassword().length, 32);
     expect(generatePassword(length: 10).length, 10);
+
+    expect(generatePassword(length: 64).length, 64);
   });
 }
diff --git a/app_crypto/test/raw_aes_test.dart b/app_crypto/test/raw_aes_test.dart
new file mode 100644
index 0000000..be45e2c
--- /dev/null
+++ b/app_crypto/test/raw_aes_test.dart
@@ -0,0 +1,28 @@
+import 'dart:typed_data';
+
+import 'package:encrypt/encrypt.dart';
+import 'package:test/test.dart';
+
+String aesEncrypt(String decoded, String password) {
+  final key = Key.fromUtf8(password);
+  // final iv = IV.fromLength(16);
+  final iv = IV(Uint8List(16));
+  final encrypter = Encrypter(AES(key));
+  return encrypter.encrypt(decoded, iv: iv).base64;
+}
+
+String aesDecrypt(String encoded, String password) {
+  final key = Key.fromUtf8(password);
+  // final iv = IV.fromLength(16);
+  final iv = IV(Uint8List(16));
+  final encrypter = Encrypter(AES(key));
+  return encrypter.decrypt(Encrypted.fromBase64(encoded), iv: iv);
+}
+
+void main() {
+  test('AES encrypt/decrypt', () {
+    var password = r'E4x*$TwbkJC-xK4KGC4zJF9j*Rh&WLgR';
+    expect(aesEncrypt('test', password), 'amGhyRRLUIoE59IiEys5Vw==');
+    expect(aesDecrypt('amGhyRRLUIoE59IiEys5Vw==', password), 'test');
+  });
+}
diff --git a/app_crypto/test/salsa20_test.dart b/app_crypto/test/salsa20_test.dart
new file mode 100644
index 0000000..3c06100
--- /dev/null
+++ b/app_crypto/test/salsa20_test.dart
@@ -0,0 +1,53 @@
+import 'package:tekartik_app_crypto/encrypt.dart';
+import 'package:tekartik_app_crypto/src/generate_password.dart'
+    show generatePassword;
+import 'package:test/test.dart';
+
+void main() {
+  void salsa20RoundTrip(String decoded, String password) {
+    var encrypter = salsa20EncrypterFromPassword(password);
+    var encrypted = encrypter.encrypt(decoded);
+    print('${decoded.length}:${encrypted.length}');
+    encrypter = salsa20EncrypterFromPassword(password);
+    expect(encrypter.decrypt(encrypted), decoded);
+  }
+
+  test('salsa20', () {
+    var salsa = salsa20EncrypterFromPassword('test');
+    var encrypted = salsa.encrypt('test');
+    salsa = salsa20EncrypterFromPassword('test');
+    expect(salsa.decrypt(encrypted), 'test');
+
+    String textWithLength(int length) {
+      return List.generate(length, (i) => i.toString().substring(0, 1)).join();
+    }
+
+    salsa20RoundTrip('test', 'test');
+    salsa20RoundTrip('', '');
+    salsa20RoundTrip('1', '2');
+    salsa20RoundTrip(textWithLength(4096), textWithLength(4096));
+    // _salsa20RoundTrip(textWithLength(40960), textWithLength(40960));
+    salsa20RoundTrip(textWithLength(4096000), textWithLength(4096000));
+
+    var password = generatePassword();
+    salsa = salsa20EncrypterFromPassword(password);
+    var sw = Stopwatch()..start();
+    var count = 1000;
+    for (var i = 0; i < count; i++) {
+      salsa.decrypt(salsa.encrypt(textWithLength(count * 10)));
+    }
+    print('salsa round trip: ${sw.elapsedMilliseconds} ms');
+
+    var encrypteds = List.generate(count, (index) => '');
+    sw = Stopwatch()..start();
+    for (var i = 0; i < count; i++) {
+      encrypteds[i] = salsa.encrypt(textWithLength(count * 10));
+    }
+    print('salsa encrypt: ${sw.elapsedMilliseconds} ms');
+    sw = Stopwatch()..start();
+    for (var i = 0; i < count; i++) {
+      salsa.decrypt(encrypteds[i]);
+    }
+    print('salsa decrypt: ${sw.elapsedMilliseconds} ms');
+  });
+}