# Can you solve the #F5CipherChallenge at Black Hat 2019?

If you are at Black Hat, definitely stop by the F5 booth in the expo hall to get a free t-shirt and participate in the F5 Cipher Challenge! You will be given both a t-shirt and an F5 Cipher Challenge card that has instructions for how to play and how to use both resources to solve the puzzle.

The puzzle can be solved using just the card and the t-shirt, but we know that some folks would prefer to solve it with code. You will still need to complete the steps on the card in order to figure out how to decipher the encrypted message, but if you want to do that with code in lieu of using the t-shirt, we've got you covered. To that end, here is a JSON block which is a model of the data structure on the t-shirt itself.

Please continue to bring your solved puzzles by the booth. Feel free to ask for help here or on Twitter, but avoid posting hints, answers, or spoilers here.

Check it out!

```{
"name": "/",
"children":  [{
"name": "E",
"children":  [{
"name": "R",
"children":  [{
"name": "R",
"children":  [{
"name": "P",
"children":  [{
"name": "A",
"children":  [{
"name": "O",
"children":  [{
"name": "E",
"children":  []
}, {
"name": "R",
"children":  [{
"name": "A",
"children":  []
}, {
"name": "N",
"children":  []
}]
}]
}, {
"name": "F",
"children":  []
}]
}, {
"name": "E",
"children":  [{
"name": "U",
"children":  []
}, {
"name": "A",
"children":  []
}]
}]
}, {
"name": "T",
"children":  [{
"name": "O",
"children":  [{
"name": "P",
"children":  [{
"name": "Y",
"children":  []
}, {
"name": "F",
"children":  []
}]
}, {
"name": "Y",
"children":  [{
"name": "A",
"children":  []
}, {
"name": "G",
"children":  []
}]
}]
}, {
"name": "N",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "U",
"children":  []
}]
}]
}]
}, {
"name": "Z",
"children":  [{
"name": "O",
"children":  []
}, {
"name": "R",
"children":  [{
"name": "O",
"children":  [{
"name": "Z",
"children":  [{
"name": "X",
"children":  []
}, {
"name": "T",
"children":  []
}]
}, {
"name": "I",
"children":  []
}]
}, {
"name": "E",
"children":  [{
"name": "D",
"children":  []
}, {
"name": "A",
"children":  []
}]
}]
}]
}]
}, {
"name": "V",
"children":  [{
"name": "E",
"children":  [{
"name": "N",
"children":  [{
"name": "L",
"children":  [{
"name": "L",
"children":  [{
"name": "L",
"children":  []
}, {
"name": "G",
"children":  [{
"name": "H",
"children":  []
}, {
"name": "N",
"children":  []
}]
}]
}, {
"name": "R",
"children":  [{
"name": "I",
"children":  [{
"name": "H",
"children":  []
}, {
"name": "S",
"children":  [{
"name": "I",
"children":  [{
"name": "L",
"children":  []
}, {
"name": "T",
"children":  []
}]
}, {
"name": "L",
"children":  []
}]
}]
}, {
"name": "F",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "F",
"children":  [{
"name": "V",
"children":  []
}, {
"name": "L",
"children":  []
}]
}]
}]
}]
}, {
"name": "I",
"children":  [{
"name": "L",
"children":  [{
"name": "S",
"children":  []
}, {
"name": "A",
"children":  []
}]
}, {
"name": "A",
"children":  [{
"name": "G",
"children":  []
}, {
"name": "A",
"children":  []
}]
}]
}]
}, {
"name": "G",
"children":  [{
"name": "N",
"children":  [{
"name": "H",
"children":  []
}, {
"name": "R",
"children":  []
}]
}, {
"name": "I",
"children":  [{
"name": "S",
"children":  [{
"name": "B",
"children":  []
}, {
"name": "P",
"children":  []
}]
}, {
"name": "N",
"children":  [{
"name": "R",
"children":  [{
"name": "M",
"children":  [{
"name": "H",
"children":  []
}, {
"name": "B",
"children":  []
}]
}, {
"name": "G",
"children":  []
}]
}, {
"name": "E",
"children":  [{
"name": "G",
"children":  [{
"name": "A",
"children":  []
}, {
"name": "H",
"children":  []
}]
}, {
"name": "R",
"children":  []
}]
}]
}]
}]
}]
}, {
"name": "L",
"children":  [{
"name": "E",
"children":  [{
"name": "U",
"children":  [{
"name": "S",
"children":  []
}, {
"name": "L",
"children":  []
}]
}, {
"name": "L",
"children":  []
}]
}, {
"name": "I",
"children":  []
}]
}]
}]
}, {
"name": "I",
"children":  [{
"name": "E",
"children":  [{
"name": "S",
"children":  [{
"name": "N",
"children":  [{
"name": "A",
"children":  []
}, {
"name": "D",
"children":  []
}]
}, {
"name": "S",
"children":  [{
"name": "Q",
"children":  []
}, {
"name": "E",
"children":  [{
"name": "T",
"children":  []
}, {
"name": "N",
"children":  [{
"name": "F",
"children":  [{
"name": "P",
"children":  []
}, {
"name": "V",
"children":  []
}]
}, {
"name": "Z",
"children":  []
}]
}]
}]
}]
}, {
"name": "D",
"children":  [{
"name": "G",
"children":  []
}, {
"name": "I",
"children":  [{
"name": "N",
"children":  [{
"name": "C",
"children":  []
}, {
"name": "D",
"children":  []
}]
}, {
"name": "S",
"children":  [{
"name": "N",
"children":  [{
"name": "O",
"children":  [{
"name": "V",
"children":  []
}, {
"name": "C",
"children":  []
}]
}, {
"name": "A",
"children":  [{
"name": "L",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "A",
"children":  []
}]
}, {
"name": "H",
"children":  []
}]
}]
}, {
"name": "O",
"children":  [{
"name": "B",
"children":  []
}, {
"name": "D",
"children":  [{
"name": "L",
"children":  []
}, {
"name": "N",
"children":  []
}]
}]
}]
}]
}]
}]
}, {
"name": "N",
"children":  [{
"name": "A",
"children":  [{
"name": "H",
"children":  [{
"name": "M",
"children":  [{
"name": "C",
"children":  []
}, {
"name": "T",
"children":  []
}]
}, {
"name": "E",
"children":  [{
"name": "E",
"children":  [{
"name": "I",
"children":  []
}, {
"name": "M",
"children":  []
}]
}, {
"name": "C",
"children":  [{
"name": "C",
"children":  []
}, {
"name": "M",
"children":  []
}]
}]
}]
}, {
"name": "Y",
"children":  [{
"name": "N",
"children":  [{
"name": "B",
"children":  [{
"name": "T",
"children":  []
}, {
"name": "S",
"children":  [{
"name": "Y",
"children":  []
}, {
"name": "B",
"children":  []
}]
}]
}, {
"name": "Y",
"children":  []
}]
}, {
"name": "A",
"children":  [{
"name": "S",
"children":  [{
"name": "K",
"children":  []
}, {
"name": "B",
"children":  [{
"name": "H",
"children":  []
}, {
"name": "A",
"children":  [{
"name": "Y",
"children":  []
}, {
"name": "B",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "N",
"children":  []
}]
}]
}]
}]
}, {
"name": "S",
"children":  [{
"name": "R",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "C",
"children":  []
}]
}, {
"name": "E",
"children":  [{
"name": "P",
"children":  [{
"name": "A",
"children":  []
}, {
"name": "I",
"children":  []
}]
}, {
"name": "B",
"children":  []
}]
}]
}]
}]
}]
}, {
"name": "E",
"children":  [{
"name": "R",
"children":  [{
"name": "T",
"children":  [{
"name": "L",
"children":  []
}, {
"name": "I",
"children":  [{
"name": "D",
"children":  []
}, {
"name": "R",
"children":  [{
"name": "D",
"children":  []
}, {
"name": "E",
"children":  [{
"name": "S",
"children":  []
}, {
"name": "D",
"children":  []
}]
}]
}]
}]
}, {
"name": "N",
"children":  [{
"name": "L",
"children":  [{
"name": "A",
"children":  []
}, {
"name": "V",
"children":  []
}]
}, {
"name": "G",
"children":  [{
"name": "E",
"children":  [{
"name": "S",
"children":  []
}, {
"name": "A",
"children":  []
}]
}, {
"name": "A",
"children":  [{
"name": "L",
"children":  []
}, {
"name": "L",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "U",
"children":  []
}]
}]
}]
}]
}]
}, {
"name": "R",
"children":  [{
"name": "C",
"children":  [{
"name": "O",
"children":  [{
"name": "P",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "N",
"children":  [{
"name": "F",
"children":  []
}, {
"name": "T",
"children":  [{
"name": "R",
"children":  [{
"name": "N",
"children":  []
}, {
"name": "M",
"children":  [{
"name": "A",
"children":  []
}, {
"name": "E",
"children":  [{
"name": "N",
"children":  []
}, {
"name": "T",
"children":  []
}]
}]
}]
}, {
"name": "T",
"children":  []
}]
}]
}]
}, {
"name": "M",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "F",
"children":  [{
"name": "D",
"children":  []
}, {
"name": "T",
"children":  []
}]
}]
}]
}, {
"name": "R",
"children":  [{
"name": "R",
"children":  [{
"name": "O",
"children":  []
}, {
"name": "N",
"children":  [{
"name": "T",
"children":  []
}, {
"name": "C",
"children":  []
}]
}]
}, {
"name": "F",
"children":  [{
"name": "E",
"children":  []
}, {
"name": "T",
"children":  [{
"name": "M",
"children":  [{
"name": "M",
"children":  []
}, {
"name": "E",
"children":  [{
"name": "N",
"children":  [{
"name": "E",
"children":  []
}, {
"name": "F",
"children":  []
}]
}, {
"name": "E",
"children":  [{
"name": "R",
"children":  []
}, {
"name": "N",
"children":  [{
"name": "P",
"children":  []
}, {
"name": "O",
"children":  []
}]
}]
}]
}]
}, {
"name": "C",
"children":  [{
"name": "T",
"children":  []
}, {
"name": "O",
"children":  [{
"name": "O",
"children":  []
}, {
"name": "R",
"children":  [{
"name": "T",
"children":  []
}, {
"name": "N",
"children":  []
}]
}]
}]
}]
}]
}]
}]
}, {
"name": "S",
"children":  [{
"name": "N",
"children":  []
}, {
"name": "V",
"children":  [{
"name": "D",
"children":  [{
"name": "U",
"children":  []
}, {
"name": "P",
"children":  [{
"name": "V",
"children":  [{
"name": "V",
"children":  []
}, {
"name": "A",
"children":  []
}]
}, {
"name": "Z",
"children":  []
}]
}]
}, {
"name": "S",
"children":  [{
"name": "D",
"children":  [{
"name": "P",
"children":  [{
"name": "P",
"children":  []
}, {
"name": "U",
"children":  [{
"name": "S",
"children":  [{
"name": "D",
"children":  []
}, {
"name": "E",
"children":  []
}]
}, {
"name": "P",
"children":  []
}]
}]
}, {
"name": "U",
"children":  [{
"name": "U",
"children":  []
}, {
"name": "P",
"children":  [{
"name": "U",
"children":  [{
"name": "E",
"children":  []
}, {
"name": "A",
"children":  []
}]
}, {
"name": "V",
"children":  [{
"name": "D",
"children":  []
}, {
"name": "I",
"children":  []
}]
}]
}]
}]
}, {
"name": "V",
"children":  [{
"name": "D",
"children":  []
}, {
"name": "R",
"children":  []
}]
}]
}]
}]
}]
}]
}]
}]
}]
}
```

You can also download and use the attached zip file which contains both the above block as well as a simplified JSON structure (they are more or less the same but one may be easier to work with depending on your preferred language.

Published Aug 07, 2019
Version 1.0