Welcome to the world of radio frequency! Before we give you real-life raw I/Q files and let you start hacking protocols, let's make sure you understand and can show basic competency in the fundamentals.

Note: challenges in this category are gated. Completion of babyrf 1 will unlock babyrf 2, and completion of babyrf 2 will unlock all the challenges in the RF category.

--- Hint ---

If you're still struggling with babyrf1 and begging for a sine,

Look at the data you've unpickled and then you'll be fine.

Digital cannot capture infinitely as much as analog a point,

So instead we have many samples discretely disjoint.

But one should look to see if they can recover analog waves that be

And once you find out then you'll realize how easy this challenge is to see.

samples.zip

Hint!

The given data is pickled. This is not a part of the challenge. This is the standard way to marshall data in Python. You should unmarshall the data in the pickles. https://docs.python.org/3/library/pickle.html

Hint!

Please do not play the pickle in VLC.

By: skat

Great job with babyrf 1! But what do we do if we have a really long string of 1s or a really long string of 0s? What kind of problem do we run into, and what kinds of solutions are there?

Note: challenges in this category are gated. Completion of babyrf 2 will unlock all the challenges in the RF category.

samples.zip

Hint!

Once you finish babyrf1, you can very easily finish babyrf2 building off of that same codebase.

Hint!

If I sent a really long string of 0s via radio... I would have no idea how many 0s I actually sent! I wonder if there's some way to solve this without needing an additional clock signal, almost like a signal that could clock itself.

Hint!

Part 2's encoding scheme is a very standard scheme first created by IBM in 1956 by Bryon E. Phelps. It is not inherently self-clocking, but probabilistically achieves the same solution at lower precisions.

By: skat

Great job completing those babyrf challenges earlier. Now, we're moving from the theoretical domain into the real world! Let's get you started with real world RF.

My buddy sent me this file the other day of some signals he recorded. We think it holds the flag, but we're not sure what kind of file this is, nor do we have any idea how to open it! Do you think you could get the flag for us?

Important: do not attempt to retransmit any given transmissions unless you know what you are doing. Always check your local laws and legislations before you transmit. In the United States, unauthorized transmission outside of certain frequency bands is illegal and can even be considered a felony offense in some cases. Radio frequency is cool, but don't get in trouble!

sample.zip

Hint!

Try learning tools that real radio hackers use. There are 2 major ones that we all use!

By: skat

Dog goes woof, cat goes meow, bird goes tweet, and mouse goes squeak. Cow goes moo, frog goes croak, and the elephant goes toot. Ducks say quack, and fish go blub, and the seal goes ow ow ow! But there's one sound that no one knows.

What does the monkey say?

Important: do not attempt to retransmit any given transmissions unless you know what you are doing. Always check your local laws and legislations before you transmit. In the United States, unauthorized transmission outside of certain frequency bands is illegal and can even be considered a felony offense in some cases. Radio frequency is cool, but don't get in trouble!

sample.zip

By: skat

Sometimes I go around with a radio in my backpack and just see what I pick up.

Once you recover the message, wrap it with irisctf{} before submitting the flag.

Important: do not attempt to retransmit any given transmissions unless you know what you are doing. Always check your local laws and legislations before you transmit. In the United States, unauthorized transmission outside of certain frequency bands is illegal and can even be considered a felony offense in some cases. Radio frequency is cool, but don't get in trouble!

sample.zip

By: skat

My arch-nemesis, Billy Bob Bobertson, just moved into a new house. I'm still upset at him for stealing my Pringles all those years ago -- my delicious lemon, cheese, and garlic Pringles! Let's break into Billy Bob Bobertson's house and steal his new Lamborghini parked in his garage. I hear they're a lot of fun to drive in the Hollywood hills.

I planted a secret radio receiver near his house and picked up some signals from when he parks in the garage. Unfortunately, it looks like the RF-based access mechanism he uses uses non-static codes, so I can't just replay a captured signal (unless I were to rolljam it, of course). There must be some way to break in!

Note: this challenge was set up using the unlicensed frequency spectrum. This is a resource shared by all. There may be other transmissions unrelated to the challenge due to other devices using the medium when these samples were recorded.

The flag format for this challenge is the sequence of bits required to be transmitted in order to open the garage. If there is a preamble, do not include it. If there are any frame header/trailer bits, do not include them. You may assume these bits will be retransmitted on the same frequency using the same modulation mechanism. If there are multiple correct answers, submit only the first. Wrap your answer with irisctf{} .

Important: do not attempt to retransmit any given transmissions unless you know what you are doing. Always check your local laws and legislations before you transmit. In the United States, unauthorized transmission outside of certain frequency bands is illegal and can even be considered a felony offense in some cases. Radio frequency is cool, but don't get in trouble!

samples.zip

By: skat