Crow Ciphers

Crow Language

Note: We already know CROW translates to NILS, NILS translates to THEA, and THEA translates to CROW in Crow Language.

Vigenère Cipher

How They Work

Crow Language

Crow Language is a monoalphabetic substitution cipher, which means that every letter in the plaintext (the original, non-encoded message) is substituted with one specific letter in the cipher 'alphabet', resulting in the ciphertext (the encoded message). For Crow language, the 'alphabet' is:

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

So if you wanted to encode "CROW", you would go through each letter of "CROW" in order and find the associated letter - 'C' becomes 'N', 'R' becomes 'I', 'O' becomes 'L' and 'W' becomes 'S', leaving you with a ciphertext of "NILS".

If you want to decode a message, you follow the same process, except translating from the letters in the ciphertext alphabet to the letters in the plaintext alphabet. So 'N' decodes to 'C', 'I' decodes to 'R', and so on.

Vigenère Cipher

The "Vigenère cipher" used in Catastrophe Crow! is significantly different than the normal version. (It is probably more accurately described as a version of the variant Beaufort cipher with the tabula recta replaced with a special table, but it is most commonly referred to as a Vigenère cipher in the community.)

To use this cipher, you need a plaintext (as explained above) and a key, which is another phrase used in encoding. You also need the following table:

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
0 R S A K F B R S I M E R B S E N N O E I T T U S L M
1 O J T A U I O S E R O E A I N P T G E T I I N E Z U
2 O E G D E S A E Q I D W T A N U I O B U E R O L T H
3 S D F E N H F F M O Y M L N F R I H A I O I S A N U
4 R H D E E I H O V T R M D O O D A I L A P J R I R I
5 L I M U O M D A E H S A D P E L W T O T A D E G K T
6 A A E W I N M Z L J D E M L S A E P H S N A Y I E H
7 E D O H N T N T A S H L D M R R O U M R F T S E N E
8 O G K A D I Y H L K A H Q I T W A E S Y S E O N B L
9 N E R E N S C H R C I X D E L T D Y T T A S T U M V

Let's follow through the process with an example plaintext "TEAM" with the key "HI".

First, write down the key repeated until it has the same length as the plaintext. In this case, we need to repeat the key twice in order for it to be long enough.

Plaintext TEAM
Key HIHI

Then, for each letter in the key and plaintext, you first find the column associated with that letter, then find a row of that column which contains the letter in the plaintext. For example, the first letter of the key is 'H' and the first letter in the plaintext is 'T', so we look at the column with the 'H' heading (the eight column), and see that 'T' is in the row with the label '7' - so the first digit of the decoded message is '7'.

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
0 R S A K F B R S I M E R B S E N N O E I T T U S L M
1 O J T A U I O S E R O E A I N P T G E T I I N E Z U
2 O E G D E S A E Q I D W T A N U I O B U E R O L T H
3 S D F E N H F F M O Y M L N F R I H A I O I S A N U
4 R H D E E I H O V T R M D O O D A I L A P J R I R I
5 L I M U O M D A E H S A D P E L W T O T A D E G K T
6 A A E W I N M Z L J D E M L S A E P H S N A Y I E H
7 E D O H N T N T A S H L D M R R O U M R F T S E N E
8 O G K A D I Y H L K A H Q I T W A E S Y S E O N B L
9 N E R E N S C H R C I X D E L T D Y T T A S T U M V

NOTE: Since there are only 10 letters in each column at most, and there are duplicate letters in many columns, not every combination of plaintext and key will be able to produce a message (for example, you can't encode 'G' with key 'H'), and some letters can be encoded multiple ways with certain keys (for example, you can encode plaintext 'S' with key 'H' as either '0' or '1').

If you repeat this process for the second letters of the key/plaintext, you get '1', with the third letters, you get '5', and the fourth letters are encoded as '3'. So, the ciphertext of the message "TEAM" with key "HI" is "7153".

Plaintext TEAM
Key HIHI
Ciphertext 7153

Decoding a message using this cipher is easier than encoding it - the first letter of the plaintext is the letter in the column of the first letter of the (repeated) key and the row of the first number in the ciphertext, and so on.