Using Encrypted Models with OpenVINO

Deploying deep-learning capabilities to edge devices can present security challenges like ensuring inference integrity, or providing copyright protection of your deep-learning models.

One possible solution is to use cryptography to protect models as they are deployed and stored on edge devices. Model encryption, decryption and authentication are not provided by OpenVINO but can be implemented with third-party tools (i.e., OpenSSL). While implementing encryption, ensure that the latest versions of tools are used and follow cryptography best practices.

This guide presents how to use OpenVINO securely with protected models.

Secure Model Deployment

After a model is optimized by the OpenVINO Model Optimizer, it’s deployed to target devices in the OpenVINO Intermediate Representation (OpenVINO IR) format. An optimized model is stored on edge device and is executed by the OpenVINO Runtime. TensorFlow (check TensorFlow Frontend Capabilities and Limitations), ONNX and PaddlePaddle models can be read natively by OpenVINO Runtime as well.

Encrypting and optimizing model before deploying it to the edge device can be used to protect deep-learning models. The edge device should keep the stored model protected all the time and have the model decrypted in runtime only for use by the OpenVINO Runtime.

deploy_encrypted_model

Loading Encrypted Models

The OpenVINO Runtime requires model decryption before loading. Allocate a temporary memory block for model decryption and use the ov::Core::read_model method to load the model from a memory buffer. For more information, see the ov::Core Class Reference Documentation.

std::vector<uint8_t> model_data, weights_data;

std::string password; // taken from an user
std::ifstream model_file("model.xml"), weights_file("model.bin");

// Read model files and decrypt them into temporary memory block
decrypt_file(model_file, password, model_data);
decrypt_file(weights_file, password, weights_data);

Hardware-based protection such as Intel Software Guard Extensions (Intel SGX) can be used to protect decryption operation secrets and bind them to a device. For more information, see the Intel Software Guard Extensions.

Use the ov::Core::read_model to set model representations and weights respectively.

Currently there is no way to read external weights from memory for ONNX models. The ov::Core::read_model(const std::string& model, const Tensor& weights) method should be called with weights passed as an empty ov::Tensor.

ov::Core core;
// Load model from temporary memory block
std::string str_model(model_data.begin(), model_data.end());
auto model = core.read_model(str_model,
    ov::Tensor(ov::element::u8, {weights_data.size()}, weights_data.data()));

Additional Resources