diff --git a/include/telephony/ril.h b/include/telephony/ril.h
index e4dccd1..64667df 100644
--- a/include/telephony/ril.h
+++ b/include/telephony/ril.h
@@ -3205,6 +3205,22 @@
  */
 #define RIL_REQUEST_CDMA_GET_SUBSCRIPTION_SOURCE 104
 
+/**
+ * RIL_REQUEST_ISIM_AUTHENTICATION
+ *
+ * Request the ISIM application on the UICC to perform AKA
+ * challenge/response algorithm for IMS authentication
+ *
+ * "data" is a const char * containing the challenge string in Base64 format
+ * "response" is a const char * containing the response in Base64 format
+ *
+ * Valid errors:
+ *  SUCCESS
+ *  RADIO_NOT_AVAILABLE
+ *  GENERIC_FAILURE
+ */
+#define RIL_REQUEST_ISIM_AUTHENTICATION 105
+
 /***********************************************************************/
 
 
diff --git a/libril/ril.cpp b/libril/ril.cpp
index e45827a..dec5507 100644
--- a/libril/ril.cpp
+++ b/libril/ril.cpp
@@ -3191,6 +3191,7 @@
         case RIL_REQUEST_REPORT_SMS_MEMORY_STATUS: return "REPORT_SMS_MEMORY_STATUS";
         case RIL_REQUEST_REPORT_STK_SERVICE_IS_RUNNING: return "REPORT_STK_SERVICE_IS_RUNNING";
         case RIL_REQUEST_CDMA_GET_SUBSCRIPTION_SOURCE: return "CDMA_GET_SUBSCRIPTION_SOURCE";
+        case RIL_REQUEST_ISIM_AUTHENTICATION: return "ISIM_AUTHENTICATION";
         case RIL_UNSOL_RESPONSE_RADIO_STATE_CHANGED: return "UNSOL_RESPONSE_RADIO_STATE_CHANGED";
         case RIL_UNSOL_RESPONSE_CALL_STATE_CHANGED: return "UNSOL_RESPONSE_CALL_STATE_CHANGED";
         case RIL_UNSOL_RESPONSE_VOICE_NETWORK_STATE_CHANGED: return "UNSOL_RESPONSE_VOICE_NETWORK_STATE_CHANGED";
diff --git a/libril/ril_commands.h b/libril/ril_commands.h
index fbd2a69..f5ef328 100644
--- a/libril/ril_commands.h
+++ b/libril/ril_commands.h
@@ -118,4 +118,5 @@
     {RIL_REQUEST_SET_SMSC_ADDRESS, dispatchString, responseVoid},
     {RIL_REQUEST_REPORT_SMS_MEMORY_STATUS, dispatchInts, responseVoid},
     {RIL_REQUEST_REPORT_STK_SERVICE_IS_RUNNING, dispatchVoid, responseVoid},
-    {RIL_REQUEST_CDMA_GET_SUBSCRIPTION_SOURCE, dispatchVoid, responseInts}
+    {RIL_REQUEST_CDMA_GET_SUBSCRIPTION_SOURCE, dispatchVoid, responseInts},
+    {RIL_REQUEST_ISIM_AUTHENTICATION, dispatchString, responseString}