Kids Crypto

Avi Zajac @_llzes

You'll need to zoom out to 33% to view the slides properly.

Hi, my name is Avi!

Crypto nerd

Lockpicker

Developer

I love rabbits, cheesecake, and cute things. Cute things like crypto!

L oryh udeelwv, fkhhvhfdnh, dqg fxwh wklqjv. Fxwh wklqjv olnh fubswr!

Introductions

Hi, my name is ${class.kids[i].yourName}

for(kids=0;kids<class.length;kids++){

Introductions

}
Tell me if you know any crypto or not already!

Some things we might go over quicker and go more in-depth in others based off of everyone's experience here huzzah!

Voting

Make your own adventure unconf class style!

Do you want to do more...

  • Learning?

  • Making cute stuff?

  • Practicing solving?

What

Is
Crypto?

cryptography

noun  cryp·tog·ra·phy  \ krip-ˈtä-grə-fē \

  1. secret writing
  2. the enciphering and deciphering of messages in secret code or cipher; also : the computerized encoding and decoding of information
  3. cryptanalysis

ciphers

steps for how to solve a problem (an algorithm) for enciphering and deciphering!

Concealing

Hiding something in plain sight in another message! Is this really a bunbun? Or is it a chicken?

 

You usually don't know for sure if the person you sent it to got it. It can be a flag, how you set up your window display, it's your choice!

 

Cardboard grille ciphers!

Transposition

When you jumble up or re-arrange what you're saying (but in a way that the other person knows how to change it back huzzah)!

RABBITS ARE CUTE

R B I S  R  C T 
 A B T  A E  U E

 

RB IS RC TA BT AE UE

Substitution

When you're replacing parts of your message with something else, like other letters, numbers, and more!

Plaintext:  ABC
Ciphertext: CDE

OR

Ciphertext: 123

How to
Solve
Puzzles

You could use online solvers...

But you don't really actually know how to solve puzzles then!

All you need is:

(graph) paper

and

pen!

This is how I'd attack a new puzzle!

Prerequisite: Is your puzzle not in English letters? Convert them back to English with simple substitution! In a few slides are cheat sheets on other possibilities whoo 🐰

0.) Look for patterns, repeating letters, 1-4 letter words

1.) Caesar Cipher (all variations)

2.) Key maybe? Try Vigenère!

3.) Have you tried Autokey yet?

4.) Playfair maybe?

5.) Google it!

2-Letters

of, to, in, it, is, be, as, at, so, we, he, by, or, on, do, if, me, my, up, an, go, no, us, am

3-Letters

the, and, for, are, but, not, you, all, any, can, had, her, was, one, our, out, day, get, has, him, his, how, man, new, now, old, see, two, way, who, boy, did, its, let, put, say, she, too, use

I, a

1-Letter

4-Letters

that, with, have, this, will, your, from, they, know, want, been, good, much, some, time

Doubles

ss, ee, tt, ff, ll, mm, oo

If you see any of these, stop!

This is all Base64

UmFiYml0IGN1dGVuZXNzIQ==

UmFiYml0cyBzdXBwb3J0IFRyZXZvckZvcmdldCE=

UmFiYml0cyBzdXBwb3J0ICNUcmV2b3JGb3JnZXQh

This is Morse Code

-.-. ..- - .     .-. .- -... -... .. - ...

This is Hexadecimal

43 68 65 65 73 65 63 61 6b 65 20 79 61 79

This is ASCII

079 111 104 032 099 117 116 101 033

(cont.)

This is binary!

01010010 01100001 01100010 01100010 01101001 01110100 01110011 00100001

"Hey Avi, how can I super easily find out the binary for any number?"

Do you know 0 and 1? Can you multiply by 2 and add numbers? You got this! ✨

128 64  32  16  8   4   2   1   Set it up like this!

0   0   0   0   0   0   0   0   So this is zero!
0   0   0   0   0   1   1   1   Add all the 1's, so
                                this becomes 7!

0   0   0   1   0   0   1   1   Guess what this is?

Did you think that was all cute? If so check out ASCII tables! ✨

Super good to remember these!

  • Everything can (and will) be broken!

  • One-time pad (OTP) --- Always destroy the key sheet immediately to prevent reuse and attacks!

  • Use something that's good enough to delay a bad person from getting your message so it's worthless once they get to it!

  • Keep your messages short and don't reuse stuff!

  • Destroy it all!

Remember, a human made these!

  1. People are repetitive, that's why we destroy keys!

  2. Do Open-Source Intelligence (OSINT) to get facts on them!
  3. See things they're very into or seem to have an interest in? Make sure to note that down somewhere.
  4. Don't be afraid to ask for clues! Even if they won't give you one they might (accidentally or purposely) give one.
  5. Check out past contests they've made for sure.

Are you really stuck on a problem?

  • Try taking a nap! Sleep is really good for your brain, especially when it's still developing 🌌
  • Eat something healthy, stay away from the soda and candy! 🐰💙🍭
  • Spend time with friends and family

If you forget everything just remember these two things:

1. Do it because it's fun

2. Ignore everyone else around you

Queercon
Crypto
Contest

This is a block of ciphertext!

What do you notice first?

What should we do next?

What's weird about this?

AZZSUAPYDD
ZRQNXSDJCC
JVYIAEYUHH
DMANTVAPGG
LIERRDJUDD
KWHVEBDEEE
XHYGVTDRHH
ATKIOVAEEE
HIBKVOPGFF
AVLTKCAHDD
YQBEHWOQGG
FUKKEDVNAA
PLKBRRHWEE
BOJYWZSTBB
GDMPRJZVDD
FDENZSLKCC
JYREDODYGG
FMQAAQOGGG
IHPTBAFWHH
VEAWSMROAA
FULGUKEKFF
SENGQCEXDD
TISZKQHEBB
PSOKSHXTFF
MAGTVOTOEE

Sweet! This looks a lot better.

Do you see anything that really sticks out right now?

   0 1 2 3 4 5 6 7 8 9
0  A Z Z S U A P Y D D
1  Z R Q N X S D J C C
2  J V Y I A E Y U H H
3  D M A N T V A P G G
4  L I E R R D J U D D 
5  K W H V E B D E E E
6  X H Y G V T D R H H
7  A T K I O V A E E E 
8  H I B K V O P G F F
9  A V L T K C A H D D 
10 Y Q B E H W O Q G G
11 F U K K E D V N A A
12 P L K B R R H W E E
13 B O J Y W Z S T B B
14 G D M P R J Z V D D
15 F D E N Z S L K C C
16 J Y R E D O D Y G G
17 F M Q A A Q O G G G
18 I H P T B A F W H H
19 V E A W S M R O A A
20 F U L G U K E K F F
21 S E N G Q C E X D D
22 T I S Z K Q H E B B
23 P S O K S H X T F F
24 M A G T V O T O E E

Oh golly we're on a roll now!

Thank goodness for whiteboard displays

   A B C D E F G H
   0 1 2 3 4 5 6 7 8 9
0  A Z Z S U A P Y D D
1  Z R Q N X S D J C C
2  J V Y I A E Y U H H
3  D M A N T V A P G G
4  L I E R R D J U D D 
5  K W H V E B D E E E
6  X H Y G V T D R H H
7  A T K I O V A E E E 
8  H I B K V O P G F F
9  A V L T K C A H D D 
10 Y Q B E H W O Q G G
11 F U K K E D V N A A
12 P L K B R R H W E E
13 B O J Y W Z S T B B
14 G D M P R J Z V D D
15 F D E N Z S L K C C
16 J Y R E D O D Y G G
17 F M Q A A Q O G G G
18 I H P T B A F W H H
19 V E A W S M R O A A
20 F U L G U K E K F F
21 S E N G Q C E X D D
22 T I S Z K Q H E B B
23 P S O K S H X T F F
24 M A G T V O T O E E

Here's the answer!

SQUAREROOTOFROPEDOWVKGIHV

 

Super cute right?

   A B C D E F G H
   0 1 2 3 4 5 6 7 8 9
0  A Z Z S U A P Y D D
1  Z R Q N X S D J C C
2  J V Y I A E Y U H H
3  D M A N T V A P G G
4  L I E R R D J U D D 
5  K W H V E B D E E E
6  X H Y G V T D R H H
7  A T K I O V A E E E 
8  H I B K V O P G F F
9  A V L T K C A H D D 
10 Y Q B E H W O Q G G
11 F U K K E D V N A A
12 P L K B R R H W E E
13 B O J Y W Z S T B B
14 G D M P R J Z V D D
15 F D E N Z S L K C C
16 J Y R E D O D Y G G
17 F M Q A A Q O G G G
18 I H P T B A F W H H
19 V E A W S M R O A A
20 F U L G U K E K F F
21 S E N G Q C E X D D
22 T I S Z K Q H E B B
23 P S O K S H X T F F
24 M A G T V O T O E E

Beyond
Binaries
Challenge

This is the 2017 challenge!

Lets break this down

  • What did you notice?
  • Are there weird symbols at all?
  • What should our first steps be?

Clue #1

You know the theme of @sidechannel_org's @Queercon challenge this year for the end!

[SUPERINCIPHERMENT]
 

Clue #2

What hotel are we at? It's definitely a classic! Also imagine the possibilities of movement in grids and crosses

[CAESAR'S PALACE]Avi  🐰 🏳️‍🌈added,​

Clue #3

I have a haiku

Your dictionary won't know

What do I like most? 🐰

Lets try it out? 🐰


Caesar
Cipher

Lets write the alphabet

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Easy right? The next thing I do is write numbers right away next to them, I recommend beginning with 0 to 25!

0  1  2  3  4  5  6  7  8  9  10 11 12
A  B  C  D  E  F  G  H  I  J  K  L  M
13 14 15 16 17 18 19 20 21 22 23 24 25
N  O  P  Q  R  S  T  U  V  W  X  Y  Z

Why am I not doing 1-26? Well, that's because...

0  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
1  B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
2  C D E F G H I J K L M N O P Q R S T U V W X Y Z A B
3  D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
4  E F G H I J K L M N O P Q R S T U V W X Y Z A B C D
5  F G H I J K L M N O P Q R S T U V W X Y Z A B C D E
6  G H I J K L M N O P Q R S T U V W X Y Z A B C D E F
7  H I J K L M N O P Q R S T U V W X Y Z A B C D E F G
8  I J K L M N O P Q R S T U V W X Y Z A B C D E F G H
9  J K L M N O P Q R S T U V W X Y Z A B C D E F G H I
10 K L M N O P Q R S T U V W X Y Z A B C D E F G H I J
11 L M N O P Q R S T U V W X Y Z A B C D E F G H I J K
12 M N O P Q R S T U V W X Y Z A B C D E F G H I J K L
13 N O P Q R S T U V W X Y Z A B C D E F G H I J K L M
14 O P Q R S T U V W X Y Z A B C D E F G H I J K L M N
15 P Q R S T U V W X Y Z A B C D E F G H I J K L M N O
​16 Q R S T U V W X Y Z A B C D E F G H I J K L M N O P
17 R S T U V W X Y Z A B C D E F G H I J K L M N O P Q
18 S T U V W X Y Z A B C D E F G H I J K L M N O P Q R
19 T U V W X Y Z A B C D E F G H I J K L M N O P Q R S
20 U V W X Y Z A B C D E F G H I J K L M N O P Q R S T
21 V W X Y Z A B C D E F G H I J K L M N O P Q R S T U
22 W X Y Z A B C D E F G H I J K L M N O P Q R S T U V
23 X Y Z A B C D E F G H I J K L M N O P Q R S T U V W
24 Y Z A B C D E F G H I J K L M N O P Q R S T U V W X
25 Z A B C D E F G H I J K L M N O P Q R S T U V W X Y
0 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425

Okay, that looked a little scary. Oops! But thankfully it's really not!

Lets try an example together.

D fxwh udeelw dqg d fxwh frujl duh iulhqgv!

Thank goodness we have a whiteboard display!


Vigenère
Cipher

0  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
1  B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
2  C D E F G H I J K L M N O P Q R S T U V W X Y Z A B
3  D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
4  E F G H I J K L M N O P Q R S T U V W X Y Z A B C D
5  F G H I J K L M N O P Q R S T U V W X Y Z A B C D E
6  G H I J K L M N O P Q R S T U V W X Y Z A B C D E F
7  H I J K L M N O P Q R S T U V W X Y Z A B C D E F G
8  I J K L M N O P Q R S T U V W X Y Z A B C D E F G H
9  J K L M N O P Q R S T U V W X Y Z A B C D E F G H I
10 K L M N O P Q R S T U V W X Y Z A B C D E F G H I J
11 L M N O P Q R S T U V W X Y Z A B C D E F G H I J K
12 M N O P Q R S T U V W X Y Z A B C D E F G H I J K L
13 N O P Q R S T U V W X Y Z A B C D E F G H I J K L M
14 O P Q R S T U V W X Y Z A B C D E F G H I J K L M N
15 P Q R S T U V W X Y Z A B C D E F G H I J K L M N O
​16 Q R S T U V W X Y Z A B C D E F G H I J K L M N O P
17 R S T U V W X Y Z A B C D E F G H I J K L M N O P Q
18 S T U V W X Y Z A B C D E F G H I J K L M N O P Q R
19 T U V W X Y Z A B C D E F G H I J K L M N O P Q R S
20 U V W X Y Z A B C D E F G H I J K L M N O P Q R S T
21 V W X Y Z A B C D E F G H I J K L M N O P Q R S T U
22 W X Y Z A B C D E F G H I J K L M N O P Q R S T U V
23 X Y Z A B C D E F G H I J K L M N O P Q R S T U V W
24 Y Z A B C D E F G H I J K L M N O P Q R S T U V W X
25 Z A B C D E F G H I J K L M N O P Q R S T U V W X Y
0 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425
A  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
B  B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
C  C D E F G H I J K L M N O P Q R S T U V W X Y Z A B
D  D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
E  E F G H I J K L M N O P Q R S T U V W X Y Z A B C D
F  F G H I J K L M N O P Q R S T U V W X Y Z A B C D E
G  G H I J K L M N O P Q R S T U V W X Y Z A B C D E F
H  H I J K L M N O P Q R S T U V W X Y Z A B C D E F G
I  I J K L M N O P Q R S T U V W X Y Z A B C D E F G H
J  J K L M N O P Q R S T U V W X Y Z A B C D E F G H I
K  K L M N O P Q R S T U V W X Y Z A B C D E F G H I J
L  L M N O P Q R S T U V W X Y Z A B C D E F G H I J K
M  M N O P Q R S T U V W X Y Z A B C D E F G H I J K L
N  N O P Q R S T U V W X Y Z A B C D E F G H I J K L M
O  O P Q R S T U V W X Y Z A B C D E F G H I J K L M N
P  P Q R S T U V W X Y Z A B C D E F G H I J K L M N O
​Q  Q R S T U V W X Y Z A B C D E F G H I J K L M N O P
R  R S T U V W X Y Z A B C D E F G H I J K L M N O P Q
S  S T U V W X Y Z A B C D E F G H I J K L M N O P Q R
T  T U V W X Y Z A B C D E F G H I J K L M N O P Q R S
U  U V W X Y Z A B C D E F G H I J K L M N O P Q R S T
V  V W X Y Z A B C D E F G H I J K L M N O P Q R S T U
W  W X Y Z A B C D E F G H I J K L M N O P Q R S T U V
X  X Y Z A B C D E F G H I J K L M N O P Q R S T U V W
Y  Y Z A B C D E F G H I J K L M N O P Q R S T U V W X
Z  Z A B C D E F G H I J K L M N O P Q R S T U V W X Y
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Lets make this less scary!

See the rows (going across) and columns (going down)? We're going to look at it like this:

abcde.....
bcdef.....
cdefg.....
defgh.....
efghi.....

PLAINTEXT

KEY

ENCIPHERED

A  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
B  B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
C  C D E F G H I J K L M N O P Q R S T U V W X Y Z A B
D  D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
E  E F G H I J K L M N O P Q R S T U V W X Y Z A B C D
F  F G H I J K L M N O P Q R S T U V W X Y Z A B C D E
G  G H I J K L M N O P Q R S T U V W X Y Z A B C D E F
H  H I J K L M N O P Q R S T U V W X Y Z A B C D E F G
I  I J K L M N O P Q R S T U V W X Y Z A B C D E F G H
J  J K L M N O P Q R S T U V W X Y Z A B C D E F G H I
K  K L M N O P Q R S T U V W X Y Z A B C D E F G H I J
L  L M N O P Q R S T U V W X Y Z A B C D E F G H I J K
M  M N O P Q R S T U V W X Y Z A B C D E F G H I J K L
N  N O P Q R S T U V W X Y Z A B C D E F G H I J K L M
O  O P Q R S T U V W X Y Z A B C D E F G H I J K L M N
P  P Q R S T U V W X Y Z A B C D E F G H I J K L M N O
​Q  Q R S T U V W X Y Z A B C D E F G H I J K L M N O P
R  R S T U V W X Y Z A B C D E F G H I J K L M N O P Q
S  S T U V W X Y Z A B C D E F G H I J K L M N O P Q R
T  T U V W X Y Z A B C D E F G H I J K L M N O P Q R S
U  U V W X Y Z A B C D E F G H I J K L M N O P Q R S T
V  V W X Y Z A B C D E F G H I J K L M N O P Q R S T U
W  W X Y Z A B C D E F G H I J K L M N O P Q R S T U V
X  X Y Z A B C D E F G H I J K L M N O P Q R S T U V W
Y  Y Z A B C D E F G H I J K L M N O P Q R S T U V W X
Z  Z A B C D E F G H I J K L M N O P Q R S T U V W X Y
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Lets try these together!

Plaintext: RABBITS
Key: HI

 

Key: GLOW

Ciphertext: NPZHU


Autokey
Cipher

A  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
B  B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
C  C D E F G H I J K L M N O P Q R S T U V W X Y Z A B
D  D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
E  E F G H I J K L M N O P Q R S T U V W X Y Z A B C D
F  F G H I J K L M N O P Q R S T U V W X Y Z A B C D E
G  G H I J K L M N O P Q R S T U V W X Y Z A B C D E F
H  H I J K L M N O P Q R S T U V W X Y Z A B C D E F G
I  I J K L M N O P Q R S T U V W X Y Z A B C D E F G H
J  J K L M N O P Q R S T U V W X Y Z A B C D E F G H I
K  K L M N O P Q R S T U V W X Y Z A B C D E F G H I J
L  L M N O P Q R S T U V W X Y Z A B C D E F G H I J K
M  M N O P Q R S T U V W X Y Z A B C D E F G H I J K L
N  N O P Q R S T U V W X Y Z A B C D E F G H I J K L M
O  O P Q R S T U V W X Y Z A B C D E F G H I J K L M N
P  P Q R S T U V W X Y Z A B C D E F G H I J K L M N O
​Q  Q R S T U V W X Y Z A B C D E F G H I J K L M N O P
R  R S T U V W X Y Z A B C D E F G H I J K L M N O P Q
S  S T U V W X Y Z A B C D E F G H I J K L M N O P Q R
T  T U V W X Y Z A B C D E F G H I J K L M N O P Q R S
U  U V W X Y Z A B C D E F G H I J K L M N O P Q R S T
V  V W X Y Z A B C D E F G H I J K L M N O P Q R S T U
W  W X Y Z A B C D E F G H I J K L M N O P Q R S T U V
X  X Y Z A B C D E F G H I J K L M N O P Q R S T U V W
Y  Y Z A B C D E F G H I J K L M N O P Q R S T U V W X
Z  Z A B C D E F G H I J K L M N O P Q R S T U V W X Y
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

This is like the other one but better!

'HELLO' was 5 characters long but our key, 'GLOW', was 4 characters! So our 'G' repeated! This isn't good so we can do this instead:

I LOVE CUTE THINGS [Plaintext]
BUN I LOVE CUTE THINGS [Key]
J FBDP QPXG NAMGNA [Ciphertext]

 

ILOVECUTETHINGS [Plaintext]
BUNILOVECUTETHI [Key]
JFBDPQPXGNAMGNA [Ciphertext]


Playfair
Cipher

B U N I E
S A R C T
D F G H K
L M O P Q
V W X Y Z

This is a 5x5 grid! I and J become one single letter so we can fit the entire alphabet in.

 

Choose a key (this example is "Bunnies are cute").

 

Don't repeat any letters!

 

Huzzah the key table is done!

E

N

E

U


Pigpen
Cipher

B

A

D

C

E

G

F

H

I

K

J

L

M

O

N

Q

P

R

T

S

U

V

X

W

Y

Z

Cardan/
Cardboard
Grille


RSA
Algorithm


Cute
Projects!

Thank you note

Do you know their favourite book? Take a page from their book and try to see if you can say something nice like, "I appreciate you," with the Cardan/Cardboard grille!

Postcards

Send your friends cute postcards with pigpen or a Caesar cipher! That way whoever takes your mail can't read it but you and your friend can!

Practice RSA

Do you really love prime numbers like Avi? Huzzah try out the algorithm with different prime numbers and see what happens!

Write a story

You can definitely write a book without enciphering it, but how about making it a little bit harder to read by using the Autokey cipher?

Crypto Contests

Try out a contest or two!

Some good friendly ones with different levels of hardness are done by Tess Schrodinger (@TessSchrodinger).

 

Many capture-the-flags (CTFs) will have a crypto puzzle somewhere or another.

 

Check out kids villages at conferences.

 

If all else fails ask Avi to make you some puzzles huzzah!

Thanks everyone 💙

Kids Crypto

By Avi Zc

Kids Crypto

BSidesDE 2017 Spawn-Kids Village Class. You'll have to zoom out in the browser to 33% to see the entirety of some of the slides, sorry!

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