diff --git a/src/lmic_config.h b/src/lmic_config.h
index 5197f046..33e336aa 100644
--- a/src/lmic_config.h
+++ b/src/lmic_config.h
@@ -89,10 +89,12 @@
 // implementation is optimized for speed on 32-bit processors using
 // fairly big lookup tables, but it takes up big amounts of flash on the
 // AVR architecture.
-#define USE_ORIGINAL_AES
+//#define USE_ORIGINAL_AES
 //
 // This selects the AES implementation written by Ideetroon for their
 // own LoRaWAN library. It also uses lookup tables, but smaller
 // byte-oriented ones, making it use a lot less flash space (but it is
 // also about twice as slow as the original).
 // #define USE_IDEETRON_AES
+//
+#define USE_MBEDTLS_AES
diff --git a/src/mbedtls_aes.c b/src/mbedtls_aes.c
new file mode 100644
index 00000000..0a40ed3c
--- /dev/null
+++ b/src/mbedtls_aes.c
@@ -0,0 +1,28 @@
+/*******************************************************************************
+ * 
+ * ttn-esp32 - The Things Network device library for ESP-IDF / SX127x
+ * 
+ * Copyright (c) 2018 Manuel Bleichenbacher
+ * 
+ * Licensed under MIT License
+ * https://opensource.org/licenses/MIT
+ *
+ * AES encryption using ESP32's hardware AES unit.
+ *******************************************************************************/
+
+#include "mbedtls/aes.h"
+#include "lmic/oslmic.h"
+
+#if defined(USE_MBEDTLS_AES)
+
+void lmic_aes_encrypt(u1_t *data, u1_t *key)
+{
+    mbedtls_aes_context ctx;
+    mbedtls_aes_init(&ctx);
+    mbedtls_aes_setkey_enc(&ctx, key, 128);
+    mbedtls_aes_crypt_ecb(&ctx, MBEDTLS_AES_ENCRYPT, data, data);
+    mbedtls_aes_free(&ctx);
+}
+
+
+#endif
\ No newline at end of file