diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index af4895e..f138feb 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -263,6 +263,22 @@
    platform hook needs to be implemented. The value is passed as the last
    component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``.
 
+-  ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This
+   flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
+   experimental.
+
+-  ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload.
+   This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
+   experimental.
+
+-  ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could
+   either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends
+   on ``DECRYPTION_SUPPORT`` build flag which is marked as experimental.
+
+-  ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector
+   (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT``
+   build flag which is marked as experimental.
+
 -  ``ERROR_DEPRECATED``: This option decides whether to treat the usage of
    deprecated platform APIs, helper functions or drivers within Trusted
    Firmware as error. It can take the value 1 (flag the use of deprecated
@@ -287,6 +303,18 @@
 -  ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU
    FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``.
 
+-  ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values:
+
+   ::
+
+     0: Encryption is done with Secret Symmetric Key (SSK) which is common
+        for a class of devices.
+     1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is
+        unique per device.
+
+   This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
+   experimental.
+
 -  ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create``
    tool to create certificates as per the Chain of Trust described in
    :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to
diff --git a/docs/getting_started/porting-guide.rst b/docs/getting_started/porting-guide.rst
index e8357b3..d634d2e 100644
--- a/docs/getting_started/porting-guide.rst
+++ b/docs/getting_started/porting-guide.rst
@@ -872,6 +872,35 @@
 
 On success the function should return 0 and a negative error code otherwise.
 
+Function : plat_get_enc_key_info() [when FW_ENC_STATUS == 0 or 1]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+    Arguments : enum fw_enc_status_t fw_enc_status, uint8_t *key,
+                size_t *key_len, unsigned int *flags, const uint8_t *img_id,
+                size_t img_id_len
+    Return    : int
+
+This function provides a symmetric key (either SSK or BSSK depending on
+fw_enc_status) which is invoked during runtime decryption of encrypted
+firmware images. `plat/common/plat_bl_common.c` provides a dummy weak
+implementation for testing purposes which must be overridden by the platform
+trying to implement a real world firmware encryption use-case.
+
+It also allows the platform to pass symmetric key identifier rather than
+actual symmetric key which is useful in cases where the crypto backend provides
+secure storage for the symmetric key. So in this case ``ENC_KEY_IS_IDENTIFIER``
+flag must be set in ``flags``.
+
+In addition to above a platform may also choose to provide an image specific
+symmetric key/identifier using img_id.
+
+On success the function should return 0 and a negative error code otherwise.
+
+Note that this API depends on ``DECRYPTION_SUPPORT`` build flag which is
+marked as experimental.
+
 Common optional modifications
 -----------------------------
 
diff --git a/docs/getting_started/tools-build.rst b/docs/getting_started/tools-build.rst
index bb707cb..c050f58 100644
--- a/docs/getting_started/tools-build.rst
+++ b/docs/getting_started/tools-build.rst
@@ -135,6 +135,33 @@
 
     ./tools/cert_create/cert_create -h
 
+.. _tools_build_enctool:
+
+Building the Firmware Encryption Tool
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``encrypt_fw`` tool is built as part of the TF-A build process when the
+``fip`` make target is specified, DECRYPTION_SUPPORT and TBB are enabled, but
+it can also be built separately with the following command:
+
+.. code:: shell
+
+    make PLAT=<platform> [DEBUG=1] [V=1] enctool
+
+``DEBUG=1`` builds the tool in debug mode. ``V=1`` makes the build process more
+verbose. The following command should be used to obtain help about the tool:
+
+.. code:: shell
+
+    ./tools/encrypt_fw/encrypt_fw -h
+
+Note that the enctool in its current implementation only supports encryption
+key to be provided in plain format. A typical implementation can very well
+extend this tool to support custom techniques to protect encryption key.
+
+Also, a user may choose to provide encryption key or nonce as an input file
+via using ``cat <filename>`` instead of a hex string.
+
 --------------
 
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