AI 앱 보안 & 모델 가중치 암호화(EncryptedSharedPreferences / NDK)

fun getOrCreateSecretKey(): SecretKey {
    val keyStore = KeyStore.getInstance("AndroidKeyStore").apply { load(null) }
    if (!keyStore.containsAlias(KEY_ALIAS)) {
        val keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore")
        keyGenerator.init(
            KeyGenParameterSpec.Builder(
                KEY_ALIAS,
                KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
            )
            .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
            .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
            .setKeySize(256)
            .build()
        )
        return keyGenerator.generateKey()
    }
    return (keyStore.getEntry(KEY_ALIAS, null) as KeyStore.SecretKeyEntry).secretKey
}