diff --git a/plat/st/common/stm32mp_auth.c b/plat/st/common/stm32mp_auth.c
new file mode 100644
index 0000000..0ef6d54
--- /dev/null
+++ b/plat/st/common/stm32mp_auth.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2019, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+
+#include <platform_def.h>
+
+#include <common/debug.h>
+#include <drivers/io/io_storage.h>
+#include <drivers/st/bsec.h>
+#include <drivers/st/stm32_hash.h>
+#include <lib/xlat_tables/xlat_tables_v2.h>
+#include <plat/common/platform.h>
+
+static const struct stm32mp_auth_ops *auth_ops;
+
+void stm32mp_init_auth(struct stm32mp_auth_ops *init_ptr)
+{
+	if ((init_ptr == NULL) ||
+	    (init_ptr->check_key == NULL) ||
+	    (init_ptr->verify_signature == NULL) ||
+	    (stm32_hash_register() != 0)) {
+		panic();
+	}
+
+	auth_ops = init_ptr;
+}
+
+int stm32mp_auth_image(boot_api_image_header_t *header, uintptr_t buffer)
+{
+	int ret;
+	uint8_t image_hash[BOOT_API_SHA256_DIGEST_SIZE_IN_BYTES];
+	uint32_t header_skip_cksum = sizeof(header->magic) +
+				     sizeof(header->image_signature) +
+				     sizeof(header->payload_checksum);
+
+	/* Check Security Status */
+	if (!stm32mp_is_closed_device()) {
+		if (header->option_flags != 0U) {
+			WARN("Skip signature check (header option)\n");
+			return 0;
+		}
+		INFO("Check signature on Open device\n");
+	}
+
+	ret = mmap_add_dynamic_region(STM32MP_ROM_BASE, STM32MP_ROM_BASE,
+				      STM32MP_ROM_SIZE, MT_CODE | MT_SECURE);
+	if (ret != 0) {
+		return ret;
+	}
+
+	/* Check Public Key */
+	if (auth_ops->check_key(header->ecc_pubk, NULL) != BOOT_API_RETURN_OK) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	/* Compute end of header hash and payload hash */
+	stm32_hash_init(HASH_SHA256);
+
+	ret = stm32_hash_update((uint8_t *)&header->header_version,
+				sizeof(boot_api_image_header_t) -
+				header_skip_cksum);
+	if (ret != 0) {
+		ERROR("Hash of header failed, %i\n", ret);
+		goto err;
+	}
+
+	ret = stm32_hash_final_update((uint8_t *)buffer,
+			       header->image_length, image_hash);
+	if (ret != 0) {
+		ERROR("Hash of payload failed\n");
+		goto err;
+	}
+
+	/* Verify signature */
+	if (auth_ops->verify_signature(image_hash, header->ecc_pubk,
+				       header->image_signature,
+				       header->ecc_algo_type) !=
+	    BOOT_API_RETURN_OK) {
+		ret = -EINVAL;
+	}
+
+err:
+	mmap_remove_dynamic_region(STM32MP_ROM_BASE, STM32MP_ROM_SIZE);
+	return ret;
+}