We have the below Implementation in Android and the same has to be integrated into Swift. Key :- "d95acd54b4a821ff32c52825q931c194" IV :- "687b9509c25a34b8ad076346s8353d67" Here Both the Key and IV are 32 bits and below is the android code. public class AESEncryption { private static final String key = "d95acd54c6a821ff32c52825b931c194"; private static final String initVector = "687b9509c25a14b8ad076346d8353d67"; static byte[] bte = hexToBytes(initVector); public static String encrypt(String strToEncrypt) { try { CommonCode.showLog("log", bte.toString()); IvParameterSpec iv = new IvParameterSpec(bte); SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), "AES"); Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING"); CommonCode.showLog("IV after logs", iv.toString()); cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv); byte[] encrypted = cipher.doFinal(strToEncrypt.getBytes()); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { return Base64.getEncoder().encodeToString(encrypted).trim(); } else { return android.util.Base64.encodeToString(encrypted, android.util.Base64.DEFAULT).trim(); } } catch (Exception e) { CommonCode.showLog("Error while encrypting: ", e.toString()); } return null; } public static String decrypt(String strToDecrypt) { try { IvParameterSpec iv = new IvParameterSpec(bte); SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), "AES"); Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING"); cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv); if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) { return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt))); } else { return new String(cipher.doFinal(android.util.Base64.decode(strToDecrypt, android.util.Base64.DEFAULT))); } } catch (Exception e) { CommonCode.showLog("Error while decrypting: " , e.toString()); } return null; } } How can we mimic the above in Swift? Here in Android they are using static byte[] bte = hexToBytes(initVector); to convert the 32bit IV into 16 bit Bytes Array I Have Tried the same approach on Swift below are the code snippet [Contents.swift](https://developer.apple.com/forums/content/attachment/60fab4f2-1496-4003-9f37-c195de95e94a)