diff --git a/library/internal_trusted_storage.h b/library/internal_trusted_storage.h
new file mode 100644
index 0000000..4b117e7
--- /dev/null
+++ b/library/internal_trusted_storage.h
@@ -0,0 +1,117 @@
+/*  Copyright (C) 2019, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+/** @file
+@brief This file describes the PSA Internal Trusted Storage API
+*/
+
+#ifndef __PSA_INTERNAL_TRUSTED_STORAGE_H__
+#define __PSA_INTERNAL_TRUSTED_STORAGE_H__
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "psa/error.h"
+#include "psa/storage_common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+#define PSA_ITS_API_VERSION_MAJOR  1  /**< The major version number of the PSA ITS API. It will be incremented on significant updates that may include breaking changes */
+#define PSA_ITS_API_VERSION_MINOR  1  /**< The minor version number of the PSA ITS API. It will be incremented in small updates that are unlikely to include breaking changes */
+
+/**
+ * \brief create a new or modify an existing uid/value pair
+ *
+ * \param[in] uid           the identifier for the data
+ * \param[in] data_length   The size in bytes of the data in `p_data`
+ * \param[in] p_data        A buffer containing the data
+ * \param[in] create_flags  The flags that the data will be stored with
+ * 
+ * \return      A status indicating the success/failure of the operation
+ 
+ * \retval      PSA_SUCCESS                      The operation completed successfully
+ * \retval      PSA_ERROR_NOT_PERMITTED          The operation failed because the provided `uid` value was already created with PSA_STORAGE_WRITE_ONCE_FLAG
+ * \retval      PSA_ERROR_NOT_SUPPORTED          The operation failed because one or more of the flags provided in `create_flags` is not supported or is not valid
+ * \retval      PSA_ERROR_INSUFFICIENT_STORAGE   The operation failed because there was insufficient space on the storage medium
+ * \retval      PSA_ERROR_STORAGE_FAILURE        The operation failed because the physical storage has failed (Fatal error)
+ * \retval      PSA_ERROR_INVALID_ARGUMENT       The operation failed because one of the provided pointers(`p_data`)
+ *                                               is invalid, for example is `NULL` or references memory the caller cannot access
+ */
+psa_status_t psa_its_set(psa_storage_uid_t uid,
+                         uint32_t data_length,
+                         const void *p_data,
+                         psa_storage_create_flags_t create_flags);
+
+/**
+ * \brief Retrieve the value associated with a provided uid
+ *
+ * \param[in] uid               The uid value
+ * \param[in] data_offset       The starting offset of the data requested
+ * \param[in] data_length       the amount of data requested (and the minimum allocated size of the `p_data` buffer)
+ * \param[out] p_data           The buffer where the data will be placed upon successful completion
+ 
+ * 
+ * \return      A status indicating the success/failure of the operation
+ *
+ * \retval      PSA_SUCCESS                  The operation completed successfully
+ * \retval      PSA_ERROR_DOES_NOT_EXIST     The operation failed because the provided `uid` value was not found in the storage
+ * \retval      PSA_ERROR_INVALID_SIZE       The operation failed because the data associated with provided uid is larger than `data_size`
+ * \retval      PSA_ERROR_STORAGE_FAILURE    The operation failed because the physical storage has failed (Fatal error)
+ * \retval      PSA_ERROR_INVALID_ARGUMENT   The operation failed because one of the provided pointers(`p_data`, `p_data_length`)
+ *                                           is invalid. For example is `NULL` or references memory the caller cannot access.
+ *                                           In addition, this can also happen if an invalid offset was provided.
+ */
+psa_status_t psa_its_get(psa_storage_uid_t uid,
+                         uint32_t data_offset,
+                         uint32_t data_length,
+                         void *p_data);
+
+/**
+ * \brief Retrieve the metadata about the provided uid
+ * 
+ * \param[in] uid           The uid value
+ * \param[out] p_info       A pointer to the `psa_storage_info_t` struct that will be populated with the metadata
+ * 
+ * \return      A status indicating the success/failure of the operation
+ * 
+ * \retval      PSA_SUCCESS                  The operation completed successfully
+ * \retval      PSA_ERROR_DOES_NOT_EXIST     The operation failed because the provided uid value was not found in the storage
+ * \retval      PSA_ERROR_STORAGE_FAILURE    The operation failed because the physical storage has failed (Fatal error)
+ * \retval      PSA_ERROR_INVALID_ARGUMENT   The operation failed because one of the provided pointers(`p_info`)
+ *                                           is invalid, for example is `NULL` or references memory the caller cannot access
+ */
+psa_status_t psa_its_get_info(psa_storage_uid_t uid,
+                              struct psa_storage_info_t *p_info);
+
+/**
+ * \brief Remove the provided key and its associated data from the storage
+ * 
+ * \param[in] uid   The uid value
+ * 
+ * \return  A status indicating the success/failure of the operation
+ * 
+ * \retval      PSA_SUCCESS                  The operation completed successfully
+ * \retval      PSA_ERROR_DOES_NOT_EXIST     The operation failed because the provided key value was not found in the storage
+ * \retval      PSA_ERROR_NOT_PERMITTED      The operation failed because the provided key value was created with PSA_STORAGE_WRITE_ONCE_FLAG
+ * \retval      PSA_ERROR_STORAGE_FAILURE    The operation failed because the physical storage has failed (Fatal error)
+ */
+psa_status_t psa_its_remove(psa_storage_uid_t uid);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // __PSA_INTERNAL_TRUSTED_STORAGE_H__
diff --git a/library/storage_common.h b/library/storage_common.h
new file mode 100644
index 0000000..07cb6e9
--- /dev/null
+++ b/library/storage_common.h
@@ -0,0 +1,58 @@
+/*  Copyright (C) 2019, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+/** @file
+@brief This file includes common definitions for PSA storage
+*/
+
+#ifndef __PSA_STORAGE_COMMON_H__
+#define __PSA_STORAGE_COMMON_H__
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** \brief Flags used when creating a data entry
+ */
+typedef uint32_t psa_storage_create_flags_t;
+
+/** \brief A type for UIDs used for identifying data
+ */
+typedef uint64_t psa_storage_uid_t;
+
+#define PSA_STORAGE_FLAG_NONE        0         /**< No flags to pass */
+#define PSA_STORAGE_FLAG_WRITE_ONCE (1 << 0) /**< The data associated with the uid will not be able to be modified or deleted. Intended to be used to set bits in `psa_storage_create_flags_t`*/
+
+/**
+ * \brief A container for metadata associated with a specific uid
+ */
+struct psa_storage_info_t {
+    uint32_t size;                  /**< The size of the data associated with a uid **/
+    psa_storage_create_flags_t flags;    /**< The flags set when the uid was created **/
+};
+
+/** Flag indicating that \ref psa_storage_create and \ref psa_storage_set_extended are supported */
+#define PSA_STORAGE_SUPPORT_SET_EXTENDED (1 << 0)
+
+/** \brief PSA storage specific error codes
+ */
+#define PSA_ERROR_INVALID_SIGNATURE     ((psa_status_t)-149)
+#define PSA_ERROR_DATA_CORRUPT          ((psa_status_t)-152)
+
+#endif // __PSA_STORAGE_COMMON_H__