Operation WIRE STORM

A Race To Relay

Your Mission

A critical situation has emerged, and we're calling on the brightest technical minds to assist. In order to transmit highly sensitive data through a known-compromised server, we’ve crafted a custom protocol, the CoreTech Message Protocol (CTMP).

Time is of the essence, and we need your expertise to rapidly handle this data before it's too late. Your mission is to develop a high-speed program in C, C++ or Rust to relay these sensitive messages via a custom proxy, to make sure our teams have all they need to know to operate safely.

CoreTech Message Protocol

The protocol has been specially crafted to encapsulate large data transfers over TCP.

Each message will be prepended with the CTMP header, consisting of:

  1. A single MAGIC byte, which will always be 0xCC

  2. A single PADDING byte, filled with 0x00

  3. The LENGTH of the data to follow, NOT including the length of the header itself.
    This field is unsigned and in network byte order

  4. Four PADDING bytes, again filled with 0x00

0 1 2 3 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAGIC 0xCC | PADDING | LENGTH | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PADDING | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | DATA ...................................................... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7

The Challenge

Our national security hangs in the balance, and every second counts. Our analysts need you to produce a proxy that can:

  1. Allow a single source client to connect on port 33333

  2. Allow multiple destination clients to connect on port 44444

  3. Accept CTMP messages over TCP from the source client, and broadcast to all destination clients. Messages should be broadcast in the order that they are received from the source.

  4. Validate the magic byte and length of the data to ensure it matches the header before broadcasting. If the data exceeds the length specified in the header, the entire message should be dropped.

You’ll need to make sure our operational support team can build your solution and verify your results, in order to gauge its operational suitability. Including documentation on expected usage and build instructions is a must.

Operational Validation

Due to the importance of this operation, our analysts have provided some tests to check your solution can handle operational data.

These tests, written for Python 3.12, will attempt to repeatedly connect to both localhost:33333 and localhost:44444, sending various CTMP messages to the source port. These will be validated against data received on the destination port.

To ensure this critical mission is a success, please run these tests against your solution prior to submission.

Grab the tests here
Submission form

Your Reward

We will invite the authors of the top submissions to a mission debriefing at our headquarters on the 11th September 2025, and arrange for travel and a hotel in Cheltenham for you to stay the night before.

On the day, you’ll have the opportunity to meet some of our teams and Technical Directors, and be taken out for lunch. You’ll also be fast-tracked to a single-stage interview for our software engineering graduate position starting September 2026, and have an opportunity to present your solution to a group of your peers on the day.

If you are successful and start a graduate role with us in September 2026, you will also receive an additional sign-on bonus of £2,000 in your first pay packet.

Entries will be assessed by an internal panel from CoreTech’s Software Engineering team for their speed, readability, memory efficiency, design and innovative approach.

Terms and Conditions

  • The deadline for receipt of submissions is 08:00 on Friday 22nd August 2025. Successful applicants will be notified by 29th August.

  • All submissions must be hosted using a public code-hosting service such as Github, and submitted using the submission form.

  • All submissions must include a detailed README for building and verifying your solution

  • All submissions must build for Ubuntu 24.04 LTS

  • Only one submission is permitted per candidate

  • You may not use third-party libraries other than your chosen language’s standard library

  • Submissions are restricted to those hoping to earn a Junior Consultant position at CoreTech in September 2026

  • Successful applicants must be available to attend our offices in Cheltenham on 11th September 2025

  • All decisions are final and at the sole discretion of CoreTech Security

  • Spotted an issue? Get in touch

Please note, due to sensitivity of the role, successful submission applicants must be British Citizens and willing to undergo extensive background checks to obtain a security clearance. Further details are given on the submission form.