Question

Помогите разгадать шифр Виженера! Вот слово: Пшхръчъа, аывдъе Ключевое слово: Код Вот что написано: Шифр Вижерена похож на шифр на шифр Цезаря. Но вместо ключевого символа. Используюется русский алфавит. Букву "А" принимается за "1". Слово "Код" принимается за ключевое слово. Шифруется слово в прямом направлении по кругу,используется ключевой символ.

Answer 1

ОТВЕТ:12 16 5  =)))))))))))))

Answer 2

Understanding the Vigenère Cipher

The Vigenère cipher is a polyalphabetic substitution cipher that was invented by Giovan Battista Bellaso in the 16th century. It is named after Blaise de Vigenère, a French diplomat who promoted its use. The Vigenère cipher is similar to the Caesar cipher, but instead of using a single shift value for all the letters, it uses a keyword to determine the shift value for each letter in the plaintext.

Steps to Decrypt the Vigenère Cipher

To decrypt a message encrypted with the Vigenère cipher, you need to know the keyword used for encryption. Here are the steps to decrypt the Vigenère cipher:

1. Write down the keyword repeatedly below the ciphertext, aligning the letters of the keyword with the corresponding letters of the ciphertext. 2. Convert both the keyword and the ciphertext to their numerical equivalents using a specific mapping. In this case, the Russian alphabet is used, with the letter "А" being equivalent to "1". 3. Subtract the numerical value of each letter in the keyword from the corresponding letter in the ciphertext. If the result is negative, add the number of letters in the alphabet to make it positive. 4. Convert the resulting numbers back to letters using the same mapping as in step 2. 5. The resulting letters form the decrypted plaintext.

Decrypting the Given Vigenère Cipher

Let's decrypt the given Vigenère cipher using the keyword "Код" (which means "code" in Russian) and the Russian alphabet mapping where "А" is equivalent to "1".

The ciphertext is: "Пшхръчъа, аывдъе"

1. Write down the keyword repeatedly below the ciphertext: ``` КодКодКодКодКодКодКод ```

2. Convert the keyword and the ciphertext to their numerical equivalents: ``` Пшхръчъа, аывдъе 16 21 24 18 31 30 1, 1 32 30 4 31 7 ```

3. Subtract the numerical value of each letter in the keyword from the corresponding letter in the ciphertext: ``` 16 21 24 18 31 30 1, 1 32 30 4 31 7 -11 -9 -6 -12 -19 -20 -19, -11 2 0 -26 -1 -23 ```

4. Convert the resulting numbers back to letters: ``` 5 12 18 6 12 10 8, 15 2 1 20 6 4 ЕЛРФЛЖИ, ОБАТФД ```

5. The decrypted plaintext is: "ЕЛРФЛЖИ, ОБАТФД"

Therefore, the decrypted message for the given Vigenère cipher is "ЕЛРФЛЖИ, ОБАТФД".

Please note that the Vigenère cipher can be more complex to decrypt if the keyword is longer or if the ciphertext is longer. In such cases, additional steps may be required to fully decrypt the message.