## Codebusters C

TheWood
Member
Posts: 13
Joined: February 20th, 2019, 2:30 pm
Division: C
State: GA

### Re: Codebusters C

Sorry mb for not posting earlier.

Find the inverse of the following hill encryption key:
BRA
CEL
ETS

KITN1931
Member
Posts: 1
Joined: February 27th, 2019, 10:19 pm

### Re: Codebusters C

Can someone give me tips on solving patristocrats????

CongminhTran
Member
Posts: 2
Joined: October 12th, 2017, 4:17 pm

### Re: Codebusters C

Hey guys,

I was just wondering if any of you guys could help me with the Hill Cipher, both decryption and encryption?

For encryption, how do you make an encryption matrix given plaintext- ciphertext letter pairs?

For decryption, how do you make a decryption matrix given plaintext-ciphertext letter pairs? Also, how do you decrypt when given a key and some ciphertext? Lastly, what if they ask you to produce a decryption matrix given only some plaintext (with number values all arranged in a matrix)? I was asking because at the Regionals test for my school, a couple of Hill Cipher questions where you had to produce A (the other one was THE) decryption matrix showed up, and we had no idea on how to do them.

If you guys could try to help, I would very much appreciate that!

jimmy-bond
Member
Posts: 333
Joined: January 8th, 2018, 11:25 pm
Division: C
State: HI
Location: On Earth, I think

### Re: Codebusters C

Hey guys,

I was just wondering if any of you guys could help me with the Hill Cipher, both decryption and encryption?

For encryption, how do you make an encryption matrix given plaintext- ciphertext letter pairs?

For decryption, how do you make a decryption matrix given plaintext-ciphertext letter pairs? Also, how do you decrypt when given a key and some ciphertext? Lastly, what if they ask you to produce a decryption matrix given only some plaintext (with number values all arranged in a matrix)? I was asking because at the Regionals test for my school, a couple of Hill Cipher questions where you had to produce A (the other one was THE) decryption matrix showed up, and we had no idea on how to do them.

If you guys could try to help, I would very much appreciate that!
Can someone give me tips on solving patristocrats????
These should go under the Code Busters thread under "Lab Events".
If life gives you melons, you're dyslexic.

Why can't dinosaurs ski? Because they're dead.

Merry Chrysler.
`Code Busters(16), DD(40), FQ(39), Forensics(36), WQ(27)`
`CriB(26), DP (11), FF(1), MM(14), P&P(6)`
`CriB(36), DD(35), FF(2), MM(20)`

Name
Member
Posts: 327
Joined: January 21st, 2018, 4:41 pm
Division: C
State: NY
Location: Syosset

### Re: Codebusters C

Sorry mb for not posting earlier.

Find the inverse of the following hill encryption key:
BRA
CEL
ETS
This year's rules doesn't cover inverting 3x3 hill keys.
However it should be
```HUV
SIL
EDE```
(I kinda stole this question, but I really liked the way they presented the Bacon cipher)
ADELE DEALT DEREK LAMPS DATED AS THE BLUNT CELLO DEALT FREED ACTORS GETS A DEATH FLYER EAGLE A YEAR YELLS OFTEN A ROAD
The first 4 letters in the ciphertext is "real"
South Woods MS/Syosset HS '21
Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Events!: Astro, Code, Fossils
Div C medals: 29

dragonfruit35
Exalted Member
Posts: 279
Joined: February 28th, 2015, 7:49 am
Division: C
State: VA
Location: TJHSST

### Re: Codebusters C

(I kinda stole this question, but I really liked the way they presented the Bacon cipher)
ADELE DEALT DEREK LAMPS DATED AS THE BLUNT CELLO DEALT FREED ACTORS GETS A DEATH FLYER EAGLE A YEAR YELLS OFTEN A ROAD
The first 4 letters in the ciphertext is "real"

Hmmm... KINDA...
`REALITY BEATS FANTASY`
PS: I think you added an extra "S" at the end of ACTORS, because that makes six letters in the group.

2019 (Duke/Reg/Cornell/States/Nats)
Mission 3/7/- Sounds 4/2/- Herp -/-/11/1/26 MV 2/3/7/3/10 Code 3/1/1/1/5
2020 (CMU/Reg/SOUP?/States?/Nats?)
GV ?/? Detector ?/? Code ?/?

Goooooooo Colonials!!!

Name
Member
Posts: 327
Joined: January 21st, 2018, 4:41 pm
Division: C
State: NY
Location: Syosset

### Re: Codebusters C

(I kinda stole this question, but I really liked the way they presented the Bacon cipher)
ADELE DEALT DEREK LAMPS DATED AS THE BLUNT CELLO DEALT FREED ACTORS GETS A DEATH FLYER EAGLE A YEAR YELLS OFTEN A ROAD
The first 4 letters in the ciphertext is "real"

Hmmm... KINDA...
`REALITY BEATS FANTASY`
PS: I think you added an extra "S" at the end of ACTORS, because that makes six letters in the group.
Yup and oops yeah I did.
South Woods MS/Syosset HS '21
Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Events!: Astro, Code, Fossils
Div C medals: 29

dragonfruit35
Exalted Member
Posts: 279
Joined: February 28th, 2015, 7:49 am
Division: C
State: VA
Location: TJHSST

### Re: Codebusters C

Decode this Vigenere-encrypted text where the five-letter key saved physicists from using Coulomb’s law infinitely for the rest of their lives.

zhy w-xoefv wwuudk felg atscvw g cifvacngj zhul ay ih klgtcu wwucdahrcme
`The word “e-field” is part of the plaintext.`
`The key is GAUSS.`

2019 (Duke/Reg/Cornell/States/Nats)
Mission 3/7/- Sounds 4/2/- Herp -/-/11/1/26 MV 2/3/7/3/10 Code 3/1/1/1/5
2020 (CMU/Reg/SOUP?/States?/Nats?)
GV ?/? Detector ?/? Code ?/?

Goooooooo Colonials!!!

starfruit
Member
Posts: 29
Joined: February 24th, 2018, 3:51 am
Division: C
State: VA

### Re: Codebusters C

the e-field equals zero inside a conductor that is in static equilibrium
2020 events - we'll seeeeee

fhs&aet '23

dragonfruit35
Exalted Member
Posts: 279
Joined: February 28th, 2015, 7:49 am
Division: C
State: VA
Location: TJHSST

### Re: Codebusters C

the e-field equals zero inside a conductor that is in static equilibrium

2019 (Duke/Reg/Cornell/States/Nats)
Mission 3/7/- Sounds 4/2/- Herp -/-/11/1/26 MV 2/3/7/3/10 Code 3/1/1/1/5
2020 (CMU/Reg/SOUP?/States?/Nats?)
GV ?/? Detector ?/? Code ?/?

Goooooooo Colonials!!!