Cryptography RRS feed

  • Question

  • Please solve this for me.

    The following enciphered message was intercepted. Derive the type of algorithm used, then recover the key, decrypt the message and answer the question




    4) Alice and Bob are going to use a Vigenere cipher with the bit stream generated by a 4 bit linear shift register:

    b<sup>,</sup><sub>1   </sub>< --b<sub>2</sub>

    b<sup>,</sup><sub>2   </sub><<sub> </sub>--b<sub>3   </sub>

    b<sup>,</sup><sub>3  </sub><-- b<sub>4</sub>

    b<sup>,</sup><sub>4  </sub><-- b<sub>2</sub>+b<sub>4</sub>

    <sub> </sub>

    String w/

                             b<sup>,</sup><sub>1   </sub>= 1

                            b<sup>,</sup><sub>2   </sub>= 0

                            b<sup>,</sup><sub>3 </sub> = 0

                            b<sup>,</sup><sub>4 </sub>=  1

    Populate the frequency table and decipher the following message in binary


                         01110010    10011000  11110010   10001010

    Sunday, December 9, 2018 6:40 PM


All replies