When you want to share a model with a third-party without revealing intellectual property, protect the model. Protecting a model conceals the implementation details of the original model by compiling it into a referenced model. The protected model includes derived files to support the optional functionalities that you specify.
When you protect a model, you can allow the user of the protected model to:
Open a read-only web view of the model, including model contents and block parameters.
Simulate the model in accelerator (default), rapid accelerator, and normal modes.
Generate code for a model that includes the protected model.
Generate HDL code for a model that includes the protected model.
Generate code for the protected model through the standalone interface, if you have Embedded Coder® and specify an ERT-based system target file for the model.
You can optionally password-protect each option. If you choose-password protection for one of these options, the software protects the supporting files by using AES-256 encryption.
When you create a protected model:
Simulink® creates and stores a protected version of the model in a file that
has the same name as the source model, with an
The original model file, with the
.slx extension, does not
change. If you protect the model through a Model block, that
Model block does not change.
Optionally, Simulink creates a project archive (
contains the protected model, a harness model for the protected model, and
additional supporting files.
This example shows how to create a protected model from a referenced model for read-only viewing, simulation, or code generation.
Configure the Model blocks in the parent model to refer to the original referenced model. This step prevents the Model blocks from becoming protected references when you create the protected model.
Open the parent model that references the model you want to protect. For
this example, open the model
To run the workflow, create a local copy of the model
sldemo_mdlref_counter that you want to protect. You
can then create a local copy of the parent model
sldemo_mdlref_basic. You must save the parent model
in the same folder as the referenced model.
sldemo_mdlref_basic model that you saved
locally. Make sure that the Model blocks
CounterC reference the
sldemo_mdlref_counter model that you saved
For each Model block, open the Block Parameters dialog box
and specify the extension
.slx in the Model
name field. When both the model and the protected model exist
in the same folder,
.slxp takes precedence over
.slx. If you do not specify an extension, then the
original Model block in the model refers to the protected
model instead of the original model. Click OK.
sldemo_mdlref_basic model, click
any of the three Model
blocks. On the Simulink Toolstrip Model Block tab, click
In the Create Protected Model dialog box, select the Simulate and Use generated code check boxes. These options allow the protected model user to simulate and generate code for a model that references the protected model. If you want to password-protect the functionality of the protected model, enter a password with a minimum of four characters. Each option can have a unique password.
If you have Embedded Coder and specify an ERT-based system target file (for example,
ert.tlc) for the model, the Code
interface field is visible.
In this example,
sldemo_mdlref_basic does not specify
an ERT-based system target file, therefore the Code
interface options are not available in the Create Protected
Model dialog box.
From the Code interface drop-down list, select one of these options:
Model reference — Specifies
code access through the model reference code interface, which
allows use of the protected model within a model reference
hierarchy. Users of the protected model can generate code from a
parent model that contains the protected model. Users can run
Model block SIL/PIL simulations with the
Top model — Specifies code
access through the standalone interface. Users of the protected
model can run Model block SIL/PIL simulations
with the protected model.
From the Content type list, select
Obfuscated source code to conceal the source
code purpose and logic of the protected model. For more information on the
model protection options, see Content type.
In the Destination folder box, specify the folder path for the protected model. The default value is the current working folder.
To automatically collect, create, and package supporting files with the
protected model, set Contents to
Model (.slxp) and dependencies in a project.
Before sharing the project, check whether the project contains the necessary supporting files. If supporting files are missing, simulating or generating code for the related harness model can help identify them. Add the missing dependencies to the project and update the harness model as needed.
Setting Contents to
(.slxp) and dependencies in a project selects the
Create harness model for protected model check box.
The harness model is included in the project and provides an isolated
environment for the Model block that references the protected
To further customize your protected model, you can:
A project archive (
.mlproj) that contains the protected
model, harness model, and supporting files appears in the specified
destination folder. To test the protected model, extract the contents of the
project archive by double-clicking it in the Current Folder browser and
specifying the destination folder. Alternatively, right-click on the project
archive and click Extract Here. The project opens, and
the extracted files are in a new folder named after the project
When you create the protected model from the Simulink Editor, a protected model report is generated and included as part of the protected model. For this example, to view the protected model report, double-click the protected model or right-click the protected-model badge icon on the block in the harness model and select Display Report.
The report contains:
A Summary, including the following tables:
Environment, providing the Simulink version and other product versions and the platform used to create the protected model.
with password protection for each
possible functionality that the protected model
supports. If you configure your protected model for
multiple targets, this table includes a list of
An Interface Report, including model interface information such as input and output specifications, exported function information, interface parameters, and data stores.
The report does not contain other sections that appear in a code generation report for non-protected models, such as a code metrics report and traceability report, because these reports include more information about the model's design.
You can test the protected model to compare it to the original model. For more information, see Test Protected Models.
To use the protected model in a model hierarchy, reference it through a
Model block such as the one included in the harness
model. The Simulation mode for Model
blocks that reference a protected model is set to
Accelerator. You cannot change the mode. For
more information, see Reference Protected Models from Third Parties.
To create a protected model from the current model, use one of these options:
On the Simulink Toolstrip Simulation tab, click the Save button arrow, then select Protected Model.
On the Simulink Toolstrip C Code tab, click the Share button arrow, then select Generate Protected Model.
To programmatically create a protected model, use the
When you create a protected model, consider these following requirements:
You must have a Simulink Coder™ or HDL Coder™ license to create a protected model.
The model must be available on the MATLAB® path.
The model cannot have unsaved changes.
The model uses the configuration that is active during protection. You cannot change the configuration of a protected model.
If the model contains variants, the protected model includes only the variant that is active during protection.
The model protection process does not preserve callbacks. For more information on creating callbacks for use with a protected model, see Define Callbacks for Protected Models
Do not rename the protected model or change its suffix. If you do so, the model is unusable until you restore its original name and suffix.
Use a unique name for the model and for models that it references. If a protected model references a model that shares a name with either a different protected model or a different model within the hierarchy of another protected model, there are limitations for using the protected models. If a top model references two protected models that have such a naming conflict, you cannot protect the top model, generate code for the top model, or simulate the top model in software-in-the-loop (SIL), processor-in-the-loop (PIL), or rapid accelerator modes.
If your model includes a non-inlined S-function, use a unique name for the .MEX file. If there is a name conflict with a different .MEX file on the MATLAB path, you cannot simulate the protected model.
The model must also meet the requirements listed in Model Reference Requirements and Limitations.
To create a protected model that supports code generation, your model must meet these requirements:
The protected model must use normal, accelerator, software-in-the-loop (SIL), or processor-in-the-loop (PIL) modes and a single target.
The protected model must not include non-inlined S-functions.
Do not select the Code Generation > Verification > Measure function execution time check box. If you have this option selected when you protect your model, the software turns off the parameter and displays a warning.
Protected referenced models must support code generation without password protection.
The protected model must be compatible with the Content type of each protected referenced model. This table provides compatibility information.
Code Generation Content Type Compatibility
|Protected Parent Model Content Type||Compatible Protected Referenced Model Content Types|
When the Content type of the protected parent model
and protected referenced models do not match, code generation applies the
Content type that provides the higher level of
protection. For example, a protected parent model set for
Binaries for protected referenced models that
are set to
Obfuscated source code. A protected
parent model set for
Readable source code
Obfuscated source code for protected
referenced models that are set to
To avoid an error during code generation of a model that includes the protected model:
The protected model name must be unique from other model names in the same model reference hierarchy.
The interfaces must match.
The parameters must be compatible.
If your protected model is referenced by another model that is protected, your model must:
Support accelerator mode. You must select
Simulate in the Create Protected Model dialog
box or set
'CodeGeneration' by using the
Use the default
Not use password-protection for simulation.
Not have callbacks.
Support the operations that the protected parent model supports without password-protection.
Use a Content type that is compatible with the Content type of the protected parent model if the protected parent model will support code generation. For a list of compatible Content type options, see the table in the preceding section.
Not reference a model that shares a name with either a different protected model or a different model within the hierarchy of another protected model.
If the model that you want to protect references a protected model, the protected referenced model must meet the preceding requirements.
A protected model that you create with the Use generated HDL code option selected allows encryption and support for simulation and HDL code generation from a model that references the protected model. You cannot obfuscate the HDL source code, have callbacks, or use nested protected models with this option. To learn more about HDL code generation limitations, see Protected Model Restrictions for HDL Code Generation (HDL Coder).