Codebusters C

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

Re: Codebusters C

Postby dragonfruit35 » January 25th, 2019, 6:38 am

I got my test back and realized that they encoded it using a 24-letter alphabet instead of 26 and I am now kicking myself, because the left symbols were A and right symbols were B, which is what I tried initially.
Oh nooooo :cry:

PS: I think this might help you :)
2018
(VT/FFX/Reg/States/Nats) MV 1/1/5/-/- Mission 3/4/4/-/- Herp 7/2/4/-/- WiFi -/-/-/4/13 Indoor Bottle Rocket -/-/-/1/- Code -/-/-/-/1
2019
(Duke/Reg/Cornell/States/Nats) MV 2/3/7/3/10 Mission 3/7/- Sounds 4/2/- Code 3/1/1/1/5 Herp -/-/11/1/26
[/color]
Goooooooo Colonials!!!

User avatar
jimmy-bond
Member
Member
Posts: 314
Joined: January 8th, 2018, 11:25 pm
Division: C
State: HI
Location: On Earth, I think

Re: Codebusters C

Postby jimmy-bond » January 25th, 2019, 9:23 am

I got my test back and realized that they encoded it using a 24-letter alphabet instead of 26 and I am now kicking myself, because the left symbols were A and right symbols were B, which is what I tried initially.
Oh nooooo :cry:

PS: I think this might help you :)
Thank you. I didn't know that. That might be the reason I mess up on most practice tests.
If life gives you melons, you're dyslexic.

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

Season's over, I can sleep now.
2019 Nats
Code Busters(16), DD(40), FQ(39), Forensics(36), WQ(27)
2018 Nats
CriB(26), DP (11), FF(1), MM(14), P&P(6)
2017 Nats
CriB(36), DD(35), FF(2), MM(20)

Carrot
Member
Member
Posts: 32
Joined: January 8th, 2018, 8:16 am
Division: Grad
State: OH

Re: Codebusters C

Postby Carrot » January 30th, 2019, 8:44 am

For solving the timed question, can you get it checked when you still have 1 or 2 errors (as often I can't think of the last word with two missing letters in it) or do you have to fully solve the problem?

User avatar
Riptide
Exalted Member
Exalted Member
Posts: 189
Joined: December 4th, 2017, 7:09 pm
Division: Grad
State: TX
Contact:

Re: Codebusters C

Postby Riptide » January 30th, 2019, 10:13 am

For solving the timed question, can you get it checked when you still have 1 or 2 errors (as often I can't think of the last word with two missing letters in it) or do you have to fully solve the problem?
Yes you can have it checked with up to 2 errors.
University of California at Berkeley '23
Seven Lakes High School '19
Seven Lakes Junior High '15

mpnobivucyxtz
Member
Member
Posts: 34
Joined: January 22nd, 2018, 6:25 pm
Division: C
State: NY

Re: Codebusters C

Postby mpnobivucyxtz » January 31st, 2019, 6:33 am

Is there a standard format for this event? Last year's nationals test provided frequency tables and the Vigenere table as well, but some invitationals I've seen provide neither. What can I expect from regionals and states?

Longivitis
Member
Member
Posts: 24
Joined: February 17th, 2018, 7:19 am
Division: Grad
State: TX

Re: Codebusters C

Postby Longivitis » January 31st, 2019, 7:23 am

Is there a standard format for this event? Last year's nationals test provided frequency tables and the Vigenere table as well, but some invitationals I've seen provide neither. What can I expect from regionals and states?
Ideally they should provide the Vigenere table, letters to numbers (A = 0, B = 1), Baconian table, modulo inverse (rarely), and texts for running key ciphers. They should also have frequency percentages for English and Spanish as well.
University of Texas at Austin '23
Cypress Lakes High School '19

Chemistry Lab, Codebusters, Game On, Science Word, Towers, We've Got Your Number

User avatar
jimmy-bond
Member
Member
Posts: 314
Joined: January 8th, 2018, 11:25 pm
Division: C
State: HI
Location: On Earth, I think

Re: Codebusters C

Postby jimmy-bond » January 31st, 2019, 8:10 am

Is there a standard format for this event? Last year's nationals test provided frequency tables and the Vigenere table as well, but some invitationals I've seen provide neither. What can I expect from regionals and states?
Ideally they should provide the Vigenere table, letters to numbers (A = 0, B = 1), Baconian table, modulo inverse (rarely), and texts for running key ciphers. They should also have frequency percentages for English and Spanish as well.
And unideally, you get nothing and have to do Vigenere the long way, write out the letters to numbers, manually calculate Baconian, and memorize the modulo inverse table as well as frequencies of English and Spanish letters. However this normally only comes up with student-made tests so I wouldn't worry about it at a higher level.
If life gives you melons, you're dyslexic.

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

Season's over, I can sleep now.
2019 Nats
Code Busters(16), DD(40), FQ(39), Forensics(36), WQ(27)
2018 Nats
CriB(26), DP (11), FF(1), MM(14), P&P(6)
2017 Nats
CriB(36), DD(35), FF(2), MM(20)

User avatar
Riptide
Exalted Member
Exalted Member
Posts: 189
Joined: December 4th, 2017, 7:09 pm
Division: Grad
State: TX
Contact:

Re: Codebusters C

Postby Riptide » January 31st, 2019, 9:58 am

Is there a standard format for this event? Last year's nationals test provided frequency tables and the Vigenere table as well, but some invitationals I've seen provide neither. What can I expect from regionals and states?
Ideally they should provide the Vigenere table, letters to numbers (A = 0, B = 1), Baconian table, modulo inverse (rarely), and texts for running key ciphers. They should also have frequency percentages for English and Spanish as well.
And unideally, you get nothing and have to do Vigenere the long way, write out the letters to numbers, manually calculate Baconian, and memorize the modulo inverse table as well as frequencies of English and Spanish letters. However this normally only comes up with student-made tests so I wouldn't worry about it at a higher level.
I don’t see any reason why event supervisors should provide a baconion table, modulo inverse, or even a letters to numbers table. Kind of takes away any skill gap this event could have for the non mono alphabetic ciphers. I do all the Vigenere by hand because it’s faster for me, but I can understand providing a table for that.
University of California at Berkeley '23
Seven Lakes High School '19
Seven Lakes Junior High '15

mpnobivucyxtz
Member
Member
Posts: 34
Joined: January 22nd, 2018, 6:25 pm
Division: C
State: NY

Re: Codebusters C

Postby mpnobivucyxtz » January 31st, 2019, 10:27 am

Is there a standard format for this event? Last year's nationals test provided frequency tables and the Vigenere table as well, but some invitationals I've seen provide neither. What can I expect from regionals and states?
Ideally they should provide the Vigenere table, letters to numbers (A = 0, B = 1), Baconian table, modulo inverse (rarely), and texts for running key ciphers. They should also have frequency percentages for English and Spanish as well.
And unideally, you get nothing and have to do Vigenere the long way, write out the letters to numbers, manually calculate Baconian, and memorize the modulo inverse table as well as frequencies of English and Spanish letters. However this normally only comes up with student-made tests so I wouldn't worry about it at a higher level.
For frequencies, I meant the frequency of the letters in a particular ciphertext. Usually seen on tests below the question, where you can fill in the plaintext letters.

User avatar
jimmy-bond
Member
Member
Posts: 314
Joined: January 8th, 2018, 11:25 pm
Division: C
State: HI
Location: On Earth, I think

Re: Codebusters C

Postby jimmy-bond » January 31st, 2019, 6:53 pm

For frequencies, I meant the frequency of the letters in a particular ciphertext. Usually seen on tests below the question, where you can fill in the plaintext letters.
Yeah, they'll usually have that. If they do not provide it, the test maker just hates children
If life gives you melons, you're dyslexic.

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

Season's over, I can sleep now.
2019 Nats
Code Busters(16), DD(40), FQ(39), Forensics(36), WQ(27)
2018 Nats
CriB(26), DP (11), FF(1), MM(14), P&P(6)
2017 Nats
CriB(36), DD(35), FF(2), MM(20)

User avatar
TheChiScientist
Member
Member
Posts: 666
Joined: March 11th, 2018, 11:25 am
Division: Grad
State: IL
Location: Suffering in a college class

Re: Codebusters C

Postby TheChiScientist » January 31st, 2019, 6:54 pm

For frequencies, I meant the frequency of the letters in a particular ciphertext. Usually seen on tests below the question, where you can fill in the plaintext letters.
Yeah, they'll usually have that. If they do not provide it, the test maker just hates children
^Facts. :( Try to memorize them the best you can in this case.
A Science Olympian from 2015 - 2019
Medal Count:30 8-)
School:Crystal Lake Central High School Wiki
Assassinator #119 and Co-Conspirator in #120
President of The Builder Cult. Builders rise up!

User avatar
Name
Member
Member
Posts: 284
Joined: January 21st, 2018, 4:41 pm
Division: C
State: NY
Location: Syosset

Re: Codebusters C

Postby Name » January 31st, 2019, 10:25 pm

For frequencies, I meant the frequency of the letters in a particular ciphertext. Usually seen on tests below the question, where you can fill in the plaintext letters.
Yeah, they'll usually have that. If they do not provide it, the test maker just hates children
^Facts. :( Try to memorize them the best you can in this case.
The average overall frequency table really isn't that useful, these are usually shorter quotes where frequencies can be skewed. Just know generally what is more common. The frequency of the particular cipher is more useful, but at least for aristocrats, I find word patterns are more useful, and not having the frequencies shouldn't be a huge problem. If they want to give a patristocrat with no frequencies though... Yeah have fun. I can't even do them with frequencies lol
South Woods MS (5 medals)/Syosset HS (24 medals)
Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Next Year: Astro, Code, hopefully Orni, and maybe Compound
2018-19 highlights
mit- 1st code, 3rd fermi cornell- 1st fermi states- 1st fermi, 3rd astro, 3rd code 19 medals

Anonymous15
Member
Member
Posts: 50
Joined: January 14th, 2019, 7:55 pm

Re: Codebusters C

Postby Anonymous15 » February 4th, 2019, 1:49 pm

Hey guys!

Do you know what the difference between K1, K2, and random alphabets are? I can't find a good definition online.

Also, for patristocrats, do you know what method is best to use? I know there are five listed on the wiki for monoalphabetic ciphers, but sometimes they don't always work when the spacings are messed up. For example, as has been said on this thread before, letter frequencies don't always work because the text can be so short.

Thanks!

UTF-8 U+6211 U+662F
Exalted Member
Exalted Member
Posts: 1491
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

Re: Codebusters C

Postby UTF-8 U+6211 U+662F » February 4th, 2019, 5:37 pm

Hey guys!

Do you know what the difference between K1, K2, and random alphabets are? I can't find a good definition online.

Also, for patristocrats, do you know what method is best to use? I know there are five listed on the wiki for monoalphabetic ciphers, but sometimes they don't always work when the spacings are messed up. For example, as has been said on this thread before, letter frequencies don't always work because the text can be so short.

Thanks!
http://www.cryptogram.org/wp-content/th ... togram.pdf for your first question

User avatar
pepperonipi
Member
Member
Posts: 57
Joined: January 21st, 2019, 11:38 am
Division: C
State: FL

Re: Codebusters C

Postby pepperonipi » February 4th, 2019, 6:29 pm

Hey guys!

Do you know what the difference between K1, K2, and random alphabets are? I can't find a good definition online.

Also, for patristocrats, do you know what method is best to use? I know there are five listed on the wiki for monoalphabetic ciphers, but sometimes they don't always work when the spacings are messed up. For example, as has been said on this thread before, letter frequencies don't always work because the text can be so short.

Thanks!
1. K1 is when there is a keyword in the plaintext and K2 is when there is a keyword in the ciphertext. I believe random alphabets are, well, random alphabets - no particular order. Definitely check out the link UTF posted before this.

2. I don't know of any "superb, easy, ultra quick" method for patristocrats because I don't think one exists. Just keep guessing and keep an open mind because some words may be way different than the words you are thinking they are. For example, you could think seeing "TH" must correspond to "THE" when it actually corresponded to the end of "FIFTH."

Good luck!
rip [hide] :?

Boca Raton Community High School
Relevant Wiki Pages: My Wiki Page (Subpages: PR · T · S) | School Wiki Page

My Events
2019: Code Busters, Fermi Questions, Thermodynamics
2019 Trials: What the Function (MIT), Detector Building (Nationals)
2020: Detector Building, Ornithology


Return to “2019 Lab Events”

Who is online

Users browsing this forum: No registered users and 0 guests