SystemServices.kt

val message = "Very large message, bigger then 250 symblos..."

// Simple Shared Preferences wrapper, will be used to save wrapped key
val storage = Storage(context)

// Creates Android Key Store and provides manage functions
val keyStoreWrapper = KeyStoreWrapper(context)

// Create and Save asymmetric key
keyStoreWrapper.createAndroidKeyStoreSymmetricKey("MASTER_KEY")
    
// Get key from keyStore
val masterKey = keyStoreWrapper.getAndroidKeyStoreSymmetricKey("MASTER_KEY")

// Creates Cipher with symmetric transformation and provides encrypt and decrypt functions
val cipher = CipherWrapper("AES/CBC/PKCS7Padding")
    
// Encrypt message with IV
val encryptedMessage = cipher.encrypt(message, masterKey, useInitializationVector = true)

// Decrypt message with IV
val decryptedMessage = cipher.decrypt(encryptedMessage, masterKey, useInitializationVector = true)