In this challenge the task is to integrate QKD encryption into the OpenSSL library. This will allow easy integration of many user applications with QKD since many already use OpenSSL for the purposes of encryption. At the end of the challenge, you will hopefully be able to demonstrate your integration by running a browser session over a TLS connection encrypted with a QKD generated key. The quantum network in this hackathon is simulated in the quantum network simulator SimulaQron, but we will be using the CQC API that was designed to be supported on the first demonstration network that is currently being built in the Netherlands.

The challenge is split up into two parts:

1. Integrate an abstract QKD API into OpenSSL
2. Implement QKD in software using the CQC API

The two parts can be done independently and they require different expertise so you can chose which one is better aligned with your own interests.

The boundary between the two tasks is a high-level QKD API. We will not be designing such an API from scratch, instead we will use one that ETSI has been working on. The fully documented API is can be found in this repository or online.

In the first task, the OpenSSL integration, the challenge is to integrate this API into OpenSSL. We provide a mock implementation for testing purposes.

In the second task, the QKD implementation, the challenge is to implement a full QKD scheme in software that uses the CQC API to interact with a simulated network.

Once both tasks are complete, the mock implementation used in the first part can be replaced with the full implementation from the second part so that we can eventually run a browser session across the network.

Looking ahead, once the demo network is up and running, this OpenSSL integration should then be able to run on top of the real thing by replacing the simulated network with actual connections to the real hardware.

The first part is to integrate the QKD API with OpenSSL and demo it by running a browser session (or some other user-level application) encrypted with QKD.

You can find the C definition of this API in the qkd_api.h header and its documentation in its own README.

We have written up a small guide that should get you started with the OpenSSL code base:

📖 OpenSSL QKD integration manual

For testing purposes we also provide you with a mock implementation of this API. This API does nothing quantum and has limited capabilities, but it should be enough for you test the OpenSSL integration without having to wait for the full software implementation from the second part. This mock implementation can be found in qkd_api and its documentation is in MOCK.md.

An actual implementation of the QKD API is also needed. The goal here is to implement the API defined in qkd_api such that the OpenSSL integration can transparently switch over from the mock implementation to the actual QKD implementation.

A high-level overview of what is necessary to produce a key using a QKD scheme is illustrated here. A more detailed description with pseudocode can be found in the Quantum Protocol Zoo. However, you may want to consider basing your implementation on the E91 protocol instead of the BB84 protocol since the creation of entangled pairs is a more fundamental operation than qubit transmission on the quantum internet.